Aeolian dust is a key component of the Earth system, influencing biogeochemical cycle, cloud microphysics, and the radiative energy budget and atmospheric dynamics, while also degrading air quality around major source regions. Large uncertainties persist in simulating atmospheric dust emission and transport, arising from the complex coupling between surface properties, boundary-layer processes, and atmospheric forcing. 

Previous efforts to evaluate the dust modelling performance of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) have mostly relied on short-term or region-specific case studies, typically focused on individual dust outbreaks or restricted geographical domains.
In this study, we present a comprehensive, year-long evaluation of WRF-Chem (v4.7.1) over the dust belt spanning North Africa, the Middle East, and Central Asia. We evaluate an ensemble of six simulations using three widely applied dust emission schemes (GOCART, AFWA, and UoC) combined with two advanced land surface models (LSM): Noah-MP and CLM4. The ensemble model output is assessed against multiple observation and reanalysis datasets, including AERONET aerosol optical depth (AOD), the MODIS-derived MIDAS dust optical depth product, and ERA5-Land surface fields of soil moisture and wind speed, which control dust emission fluxes. 

Our analysis shows that land-surface representation exerts a strong influence on dust emission magnitude and spatial distribution, with Noah-MP yielding systematically higher agreement with observed meteorology and AOD. Among the dust emission schemes, AFWA performs most consistently, while UoC04 exhibits lower precision. Empirical scaling factors are derived for each dust emissions–LSM pairing.To our knowledge this is the first year-round, multi-scheme assessment of WRF-Chem dust performance, offering guidance for improved dust forecasting and climate applications. 

How to cite: Deb, S., Louca, E., Violaris, A., Kiriakidis, P., Proestos, Y., and Christoudias, T.: Evaluation of WRF-Chem aeolian dust emission and land surface models over the dust belt., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-192, https://doi.org/10.5194/egusphere-egu26-192, 2026.

EGU26-192

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Dust aerosols constitute a key component of the Earth–atmosphere system, affecting the radiation budget, the microphysical and optical properties of clouds, air quality, terrestrial and aquatic processes, and human health. Dust-related impacts are critically governed by the atmospheric load of mineral particles and are amplified when the dust burden substantially exceeds background levels. Such conditions, commonly referred to as episodes or events, are exceptional and characterized by pronounced spatiotemporal heterogeneity.

In this study, we present an intercomparison of three state-of-the-art climate models (EC-Earth3, CESM2, and NorESM2) and the GiOcean Reanalysis in representing dust events over the Mediterranean, North Africa, and the Middle East during the period 2003–2018. A percentile-based threshold methodology is applied to  daily dust optical depth (DOD) and aerosol optical depth (AOD) values, at both the grid-cell and regional scales, to identify three intensity-based episode categories: weak, moderate and extreme.  In addition, the satellite-based MIDAS dataset, which provides columnar DOD at 550 nm, is used as a reference for model evaluation.

The primary objective of this study is to assess inter-model differences in the representation of dust episode frequency of occurrence and intensity across multiple spatiotemporal scales, considering both free-running and nudged model configurations. Our working framework enables a comprehensive analysis by: (i) evaluating the ability of state-of-the-art climate models to represent different dust episode regimes, and (ii) investigating how threshold definitions influence the resulting spatiotemporal patterns of dust episodes. Finally, the outcomes of this study are expected to substantially enhance understanding of the strengths and limitations of climate models in depicting dust episode characteristics, thereby supporting improved projections under different climate scenarios throughout the 21^st century.

How to cite: Mavroudis, F., Gkikas, A., Barahona, D., Gonçalves Ageitos, M., Leung, D., Garcı́a-Pando, C. P., Haugvaldstad, O. W., and Sotiropoulou, G.: How well do climate models represent dust events over the Mediterranean, North Africa, and the Middle East?, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18628, https://doi.org/10.5194/egusphere-egu26-18628, 2026.

EGU26-18628

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Dust aerosols are a key component of the Earth's climate system. However, global climate models often depict mineral dust as a uniform aerosol. This simplification limits the physical realism of dust simulations, necessitating comparison with available observations to determine whether mineralogical variability is accurately represented when incorporated into a global climate-aerosol model.

In this study, we examine how well a mineralogical soil database translates into realistic mineral-resolved dust transport and deposition in the global climate model ICON coupled with the aerosol module HAM. This implementation is based on the mineralogical soil database of Journet et al. (2014), as modified by Goncalves-Ageitos et al. (2023), and it explicitly represents 12 individual minerals. Using multi-year global simulations, we evaluate the simulated mineralogical dust cycle with a focus on emission patterns, transport pathways, regional deposition, and the representation of seasonal and interannual variability. Model results are compared with available observations and datasets to assess the added value and limitations of mineral-resolved dust representation.

The evaluation demonstrates where mineralogical information helps to better constrain dust transport and deposition and identifies key uncertainties that remain. These results provide a basis for future work on mineral-specific dust deposition and its role in biogeochemical cycles.

How to cite: Hofmann, E., Wagner, R., and Schepanski, K.: How well does a mineralogical soil database translate into realistic mineral-resolved dust transport and deposition in a global climate model?, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7789, https://doi.org/10.5194/egusphere-egu26-7789, 2026.

EGU26-7789

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Mineral dust is a major atmospheric aerosol, affecting climate, air quality, and human health through radiative and microphysical processes. The Iberian Peninsula is frequently impacted by dust intrusions from North Africa, leading to episodic exceedances of PM₁₀ concentrations that challenge operational air quality forecasts. Accurate simulation of dust emission and transport remains difficult due to uncertainties in soil erodibility, land surface characteristics, and meteorological drivers.

In this study, we assess the impact of two newly developed high-resolution soil erodibility datasets on regional dust simulations using WRF-Chem with the GOCART scheme. The first dataset, EROD, improves dust source representation by integrating fine-resolution topography (GMTED2010), achieving 0.0625° (≈5 km) resolution globally and 1 km locally for the Iberian Peninsula. The second dataset, SOILHD, further refines dust source characterization by incorporating local-scale soil composition (sand, silt, clay fractions) and removing areas erroneously classified as bare soil, reaching 1 km resolution globally. These datasets aim to capture the spatial heterogeneity of dust sources, which is critical in semi-arid regions with sparse vegetation and variable soil properties.

We conduct WRF-Chem simulations for five periods between 2022 and 2025, representing a range of dust episodes with local and long-range transport. Model performance is evaluated against PM₁₀ measurements from the SINQLAIR network across coastal and inland stations in the Region of Murcia. Results indicate that the high-resolution datasets substantially improve the spatial and temporal representation of dust emissions. Inland and low-anthropogenic-influence stations show better agreement with observed PM₁₀ peaks in both magnitude and timing compared to simulations using standard coarse-resolution erodibility fields. At coastal and industrially influenced sites, improvements are more limited due to missing anthropogenic emissions and additional aerosol components, but statistical metrics such as correlation, Mean Bias Error (MBE), and Root Mean Square Error (RMSE) still indicate significant enhancement.

Overall, the results demonstrate that high-resolution, type–aware soil erodibility datasets significantly enhance the skill of dust simulations in WRF-Chem, reducing biases and capturing observed variability more accurately. These findings underscore the importance of detailed soil and topographic information for regional dust modeling and highlight the potential benefits of incorporating such datasets into operational dust forecasting systems.

How to cite: Segado-Moreno, L., Montávez, J. P., Raluy-López, E., Garnés-Morales, G., Cordero, A., and Jiménez-Guerrero, P.: Improving dust emission in WRF-Chem GOCART scheme using a high-resolution erodibility dataset, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10600, https://doi.org/10.5194/egusphere-egu26-10600, 2026.

EGU26-10600

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Recent observations show that large mineral dust particles are more abundant in the atmosphere than expected and travel further than their mass and theoretical rapid deposition allow for. The presence of these large particles alters the impact of dust on Earth’s radiative budget, carbon and hydrological cycles, and human health. Research into the impacts of the mechanisms influencing large dust particle lifetime in models is vital in ascertaining how large dust particles travel thousands of kilometres further than expected. We employ a series of model simulations to better understand the long-range transport of large particles from the Sahara to the West Atlantic. We present results from two models—HadGEM3A and ICON-ART—which are run at differing resolutions and with different dust representations (size bins and lognormal modes). Observations are used to verify long-range transport in model simulations, including in-situ aircraft observations at the Sahara, Canary Islands, Cape Verde, and Caribbean. Coarse particle mass loading (validated against observations) is limited by excessively rapid deposition in both models, but is further limited in ICON-ART by a reduced size-range representation, with the coarsest mode having a mean diameter by mass of 14.2 µm, whereas the maximum dust size in HadGEM3A extends to 63.2 µm. The sensitivity of large particle long-range transport to sedimentation, convective and turbulent mixing, shortwave absorption, and impaction scavenging are tested in global HadGEM3A climate simulations. A reduction in sedimentation by 80% is required to bring the modelled large particle transport into agreement with aircraft observations. None of the other processes tested were able to make the multiple order of magnitude changes to long-range large particle concentration in the model required for agreement with the observations. Convective and turbulent mixing in the model have minimal impact on large particle long-range transport, but are key in controlling the vertical distribution in the Saharan air layer and marine boundary layer, respectively. This work adds to the growing body of evidence that points to processes involved in large mineral dust transport and deposition which are not represented accurately or at all in models, which counteract the sedimentation of large particles in the real-world.

How to cite: Ratcliffe, N., Ryder, C., Bellouin, N., Klose, M., Woodward, S., Jones, A., Johnson, B., Wieland, L.-M., Baer, A., Gasteiger, J., and Weinzierl, B.: New processes to counteract sedimentation of coarse dust particles are required for climate models to agree with observations, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3373, https://doi.org/10.5194/egusphere-egu26-3373, 2026.

EGU26-3373

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Haboobs, dust storms triggered by convective cold pool outflows, contribute significantly to the global dust cycle and cause severe socioeconomic impacts through rapid visibility reduction and health hazards. However, haboob processes are inadequately represented in current reanalysis products (MERRA-2, EAC4) due to insufficient resolution to resolve mesoscale convection and hydrostatic dynamics that cannot properly describe the small-scale vertical motions. To date, haboobs have been studied primarily through individual cases and regional statistics, while systematic global-scale understanding remains lacking. This study investigates the global spatiotemporal patterns of haboobs and quantifies their contributions to dust emissions using the 12.5-km iDust model with analysis wind nudging. We perform multi-year global simulations, validate them against ground-based and satellite observations, and systematically identify and characterize haboob events worldwide. Our findings reveal global haboob patterns and their role in the dust cycle, advancing scientific understanding of convective dust processes.

How to cite: Chong, M. and Chen, X.: Understanding Global Haboobs Using iDust, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4611, https://doi.org/10.5194/egusphere-egu26-4611, 2026.

EGU26-4611

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Due to its radiative effects, mineral dust constitutes a critical component in global aerosol climate models. However, the representation of dust emissions currently remains a substantial source of uncertainties in dust model simulations. Convective systems are major contributors to dust emission. Moist convection, however, is still a sub-grid scale process in most climate models, which has to be parameterized. Recent comparison studies between high-resolution, convection-resolving simulations and models with horizontal resolutions, that do not allow for considering moist convection explicitly, have revealed the model resolution as a key driver for the model uncertainties.  To further evaluate the impact of model resolution on dust emission, we conducted an analysis based on surface winds from two distinct modeling frameworks: (i) the coarse-resolution CMIP6 model ensemble, where convection is parameterized, and (ii) high-resolution ICON simulations from the DYAMOND (DYnamics of the Atmospheric general circulation Modeled On Non-hydrostatic Domains) project, which explicitly resolve moist convection. An indicator of dust emissions is the so-called dust emission potential, which is calculated offline for these different datasets and systematically evaluated for key global source regions. The analysis reveals pronounced regional and seasonal differences in the magnitude and characteristics of the modeled dust emission proxy. To investigate the origins of these uncertainties, we further compare the model outputs with high-resolution regridded data and analyze the diurnal cycle of dust emissions in selected source regions with a special focused investigation of the Central Asian dust sources. The results highlight the necessity of using high-resolution emission modeling in specific dust source regions to more accurately represent dust-generating processes and their climate impacts.

How to cite: Kunze, P., Heinold, B., and Tegen, I.: The impact of grid resolution on global dust emission potential, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7557, https://doi.org/10.5194/egusphere-egu26-7557, 2026.

EGU26-7557

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Saharan dust outbreaks intermittently exert strong radiative, air quality and depositional impacts across the Euro-Mediterranean, due to the intrinsic characteristics of this phenomenon, yet their numerical reproduction remains challenging. Here we investigate modelling strategies that preserve spatio-temporal consistency in sub seasonal integrations with WRF-Chem, focusing on three major dust intrusions affecting Italy in 2024: 25 March to 1 April, 18 to 21 June, and 8 to 14 July. We perform a set of reanalysis driven experiments over a single 5 km grid domain spanning North Africa and the Mediterranean into continental Europe, forced by ECMWF IFS analyses at 6 hourly frequencies. Model performance is assessed against complementary observing systems over the Euro-Mediterranean with emphasis on Italy. Our core objective is to quantify how spectral nudging can mitigate large scale phase errors and long run drift, while avoiding an overly constrained mesoscale circulation that may distort dust emission, uplift and transport. In addition, using a sequence of sensitivity runs initialized at increasing lead times, we estimate event dependent spin-up thresholds that stabilize domain integrated dust mass and optical depth, while maintaining realistic emission timing, intensity and extension, to suggest a transferable good practice workflow for episodic dust reanalysis and for longer sub seasonal experiments. Overall, this study frames spectral nudging not as an arbitrary choice but as a tunable constraint whose optimal setting depends on the intended balance between large scale fidelity and internally generated aerosol meteorology feedback, with clear implications for WRF-Chem based dust assessments over Italy and the central western Mediterranean. The focus is on the fact that, despite an approximate 40% increase in computational time, the use of spectral nudging emerges as an optimized approach, both in terms of physical consistency and final computational cost savings. This technique proves particularly advantageous in reducing the overall number of simulations required within the context of sub-seasonal reanalysis.

How to cite: Chiappini, A., Rizza, U., Passerini, G., and Ricchi, A.: Sub-seasonal WRF-Chem reanalysis of extreme Saharan dust outbreaks in spring-summer 2024: balancing phase consistency and aerosol realism, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-22343, https://doi.org/10.5194/egusphere-egu26-22343, 2026.

EGU26-22343

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Mineral dust aerosol shapes the global climate, mainly through interactions with radiation and clouds, and especially on the regional level close to major emission sources. However, the Coupled Model Intercomparison Project, phase six (CMIP6) models with coupled dust emission parameterization schemes fail to reproduce the 55 ± 30% increase in atmospheric dust concentration since 1850 (Kok et al. 2023). In the present study, we construct the historically changing monthly 'Dust Plumes' (DuPlumes) climatology (Sudarchikova et al. in prep.) and investigate implications of changing dust aerosol for the global climate in ICON-XPP, Germany's designated model for CMIP7. DuPlumes consists of a parameterized analytical framework, originally designed for anthropogenic aerosols (Stevens et al. 2017).  To create the representation of natural desert-dust aerosols, this study utilizes reanalysis data of dust optical depth, measurement data of scattering properties, and a marine-core-based reconstruction of the historical trend. To constrain the spatial pattern of present-day optical depth by observation, we use data of four reanalysis products (CAMS, MERRA2, JAero, and NAAPS), monthly averaged for the decade around the year 2010 (2004–2015). Plume functions related to ten dust plumes globally are fitted to the data using a gradient descent algorithm. The fit achieves a spatial correlation of r=0.98 with the data, with maximum deviations in summer of 0.08, or 2% of maximum aerosol optical depth, which is smaller than the uncertainty measured across the reanalysis ensemble. Compared to the currently implemented static ICON-XPP dust climatology, the reanalysis ensemble and, subsequently, dust plumes suggest considerably higher optical depth (~0.1) in the Eastern Asian Taklamakan and Gobi Desert regions. The vertical profile is informed by the 2007–2019 climatology derived from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) retrievals. We also include measurements of dust scattering properties from literature, including in-situ data and laboratory measurements. Ongoing work includes ICON-XPP experiments with dust optical properties represented by DuPlumes. These allow us to estimate the spatial pattern of effective radiative effects of the present-day natural dust relative to the pre-industrial levels.

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Kok, J.F., Storelvmo, T., Karydis, V.A., Adebiyi, A.A., Mahowald, N.M., Evan, A.T., He, C., Leung, D.M.: Mineral dust aerosol impacts on global climate and climate change. Nat Rev Earth Environ. 4, 71–86 (2023). https://doi.org/10.1038/s43017-022-00379-5

Stevens, B., Fiedler, S., Kinne, S., Peters, K., Rast, S., Müsse, J., Smith, S.J., Mauritsen, T.: MACv2-SP: A parameterization of anthropogenic aerosol optical properties and an associated Twomey effect for use in CMIP6. Geoscientific Model Development. 10, 433–452 (2017). https://doi.org/10.5194/gmd-10-433-2017

How to cite: Sarnighausen, C., Sudarchikova, N., and Fiedler, S.: Towards Understanding the Climate Response to the Historical Dust Increase in ICON-XPP, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7253, https://doi.org/10.5194/egusphere-egu26-7253, 2026.

EGU26-7253

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Dust aerosols impact High Mountain Asia (HMA) glacier mass balance through reducing albedo (direct effect) and affecting the accumulation of glacial materials by disturbing precipitation (indirect effect), but the mechanism remains unclear.  Using a regional climate model and coupling it to a glacier energy-mass balance model for the period 2016-2022, we demonstrate that dust amplifies glacier mass loss by 6%, primarily by reducing solid precipitation (46%) and albedo (41%). This dust-induced glacier retreat leads to significant declines in water storage, particularly in the Tarim Basin (-13%). As dust emissions are projected to rise, transboundary mitigation is urgently needed to preserve regional water security.

How to cite: Mao, X.: Dust amplified Glacier Mass Loss in High Mountain Asia, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7051, https://doi.org/10.5194/egusphere-egu26-7051, 2026.

EGU26-7051

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Sand and dust storms (SDS) are among the most impactful atmospheric hazards, affecting air quality, climate, ecosystems, and socio-economic activities across continents. East Asia is one of the world’s major dust source regions, and recent observations indicate a renewed increase in SDS frequency and intensity since the mid-2010s, with several extreme events occurring in 2021, 2023, and 2025. This contribution presents recent advances in SDS early warning and forecasting developed at the WMO Asian Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS) Regional Center, hosted by the China Meteorological Administration.

We highlight progress in multi-source monitoring, multi-model forecasting, and artificial intelligence (AI) applications for SDS prediction. Satellite-based minute-scale dust identification has been achieved through multi-sensor data fusion, enabling near-real-time monitoring of dust severity and three-dimensional vertical structure by integrating satellite, lidar, radar, and ground-based observations. On the forecasting side, operational multi-model ensemble systems provide regional dust concentration, optical depth, emission, and deposition products. A machine-learning-based ensemble correction approach further improves surface dust concentration forecasts by optimally combining multiple models based on their historical performance.

In addition, an AI-driven global coupled aerosol–meteorology forecasting system has been developed, delivering 5-day, high-resolution forecasts of dust optical depth and surface concentrations. Case studies demonstrate that this system captures long-range dust transport from both Asian and Saharan sources, including events affecting Europe, with forecast skill exceeding that of several regional numerical models.

As a WMO SDS-WAS Asian Regional Center, we emphasize the importance of strengthening collaboration with the WMO SDS-WAS program and other regional nodes. Enhanced data sharing, harmonized observational datasets, and coordinated multi-model and AI-based forecasting efforts are essential to improve global SDS early warning capabilities. The experience gained in Asia offers valuable insights for Europe and other downwind regions, supporting transboundary aerosol monitoring, risk assessment, and mitigation strategies at the global scale.

How to cite: An, L.: Developments in Monitoring and Multi-Model Applications of Dust Weather in SDS-WAS ASIAN REGIONAL CENTER, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4602, https://doi.org/10.5194/egusphere-egu26-4602, 2026.

EGU26-4602

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The characteristics and potential influence of dust events under the background of Northeast China Cold Vortex (NCCV) have rarely been investigated. Based on meteorological observational data and ERA5 reanalysis data from 2015 to 2023, we examined the spatiotemporal and environmental characteristics of dust events under NCCV and non-NCCV conditions and explored the potential impacts of the NCCV on dust events. The results indicate that dust days in Northeast China exhibited a trend of first decreasing and then increasing during the study period, and severe dust events mainly occurred in central Inner Mongolia, a key dust source region in China. Dust days associated with the NCCV accounted for 32.7% of the total dust days, and their station-frequency ratio reached 43.7%. Dust events were predominantly concentrated in the southwest quadrant of the NCCV periphery (60.1%), mostly within a range of 1.0–2.6 times the NCCV radius. This distribution pattern can be attributed to the strong baroclinity often related to the low-level shear lines and dry ambient conditions in this region. Moreover, strong downward momentum transfer and weakly stable stratification within the planetary boundary layer under NCCV conditions also facilitated the formation of dust events. This study reveals the important impacts of the NCCV on dust events, thereby providing a scientific basis for further understanding the formation mechanisms of such events.

How to cite: Li, X. and Xu, S.: Characteristics and impacts of dust events under the background of Northeast China Cold Vortex (NCCV), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5478, https://doi.org/10.5194/egusphere-egu26-5478, 2026.

EGU26-5478

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Recent observations over the Arabian Peninsula reveal an apparent paradox: while the frequency of synoptically forced dust storms has declined since the late 1990s, mean near-surface dust concentrations, poor-visibility events, and chronic air-quality degradation have increased. This contrast is often attributed to changes in emissions or land use. Here, we propose instead that the paradox reflects an abrupt dynamical regime shift in large-scale circulation and boundary-layer ventilation. The Arabian Peninsula is strongly influenced by baroclinic disturbances generated by short-wavelength Rossby waves radiated from the subtropical jet stream (STJ). These disturbances drive deep vertical coupling, strong surface winds, and efficient ventilation of the boundary layer. Multiple independent diagnostics indicate that the regional circulation underwent an abrupt transition in the late 1990s, marked by increased static stability, increased pressure depth of the troposphere, a reduction in the squared meridional temperature gradient, and a corresponding decline in mean available potential energy. These changes are consistent with weakened Rossby wave radiation and reduced baroclinic activity downstream of the STJ.

The consequences of this transition are twofold. First, reduced baroclinic activity suppresses deep convection, strong downdrafts, and synoptically driven high-wind events, leading to a decline in dust storm frequency. Second, and critically, weakened ageostrophic flow at the top of the boundary layer reduces shear-driven turbulence generation, particularly under stable boundary-layer conditions. The resulting collapse of vertical mixing limits ventilation and increases the residence time of dust near the surface, leading to higher mean surface concentrations despite fewer extreme dust events.

This framework extends a dynamical theory previously developed to explain abrupt increases in fog under weakened baroclinic forcing to mineral dust and air quality. The results demonstrate that reduced ventilation alone is sufficient to reconcile declining dust storm frequency with increasing surface dust loading, highlighting the nonlinear sensitivity of boundary-layer processes to large-scale circulation changes. The findings underscore the importance of regime shifts in atmospheric dynamics for understanding long-term changes in dust, pollution, and visibility in arid regions.

How to cite: Mhawish, A., Gunturu, U. B., Alamoudi, S., Alduaji, S., and Alqahtani, J.: Fewer Dust Storms, Greater Dust Concentration in the Air, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19014, https://doi.org/10.5194/egusphere-egu26-19014, 2026.

EGU26-19014

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Abstract: Dust emissions from the Tarim Basin, China, are governed by strong surface heterogeneity and finite sediment supply, two pivotal controls that can induce source depletion and wind-flux hysteresis during dust events. In this study, we adopt the source-limited dust emission (SLDE) scheme proposed by Shao (2025) and develop a landform-specific parameterization that couples remotely sensed surface units with field-measured particle-size data. Specifically, we generate a mutually exclusive seven-class geomorphology map in Google Earth Engine via a hierarchical decision tree, which integrates multi-source datasets including topography (MERIT DEM), vegetation coverage (MODIS NDVI), surface water occurrence (JRC Global Surface Water), and Sentinel-1 backscatter texture characteristics. The resultant geomorphological units comprise mobile dunes, vegetated hummock dunes, fixed/semi-fixed sandy lands, interdune areas, gobi/deflation surfaces, fluvial-lacustrine sediments, and mountain/loess terrains. For each unit, class-specific particle-size distributions are compiled from in-situ measurements and converted into discretized lookup tables, which serve as static input parameters for the SLDE scheme. Initial diagnostic experiments at both column and point scales, driven by hourly 10-m wind data from ERA5-Land (for the April 2020 case study), reveal distinct dust emission regimes across different landform types. On supply-limited surfaces-notably gobi/deflation and fluvial-lacustrine units-our simulations demonstrate that dust flux declines markedly under sustained high-wind conditions as the near-surface sediment reservoir becomes depleted, leading to pronounced hysteresis in the wind-flux relationship. The effective emission efficiency decreases from nearly unity at the onset of dust events to ~0.1 by the late stages, even when wind speeds remain above the threshold friction velocity for dust emission. In contrast, transport-limited behavior dominates in regions with ample sediment supply. These findings establish a physically interpretable framework for deriving SLDE parameters from geomorphological classifications and particle-size properties. Ongoing gridded simulations will quantify the extent to which sediment depletion reshapes the spatial contribution of key deflation zones, as well as the event-integrated dust emission budget, relative to results derived under conventional transport-limited assumptions.

Keywords: Source-limited dust emission; Source depletion; Wind-Flux Hysteresis; Particle size distribution

How to cite: Guo, Y., Gao, X., Lei, J., and Cornelis, W.: Source-Limited Dust Emission in the Tarim Basin, China: Landform-Specific Parameterisation and Wind-Flux Hysteresis, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19098, https://doi.org/10.5194/egusphere-egu26-19098, 2026.

EGU26-19098

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Sand dunes are not typically considered a major contributor to atmospheric dust loading due to coarse grain sizes and the infrequent observation of dust emission events. In vegetated dune systems, dust emission is less common as plant cover inhibits wind erosion. However, disturbances, such as fire, can rapidly remove protective vegetation cover which exposes resident fine sediments to wind erosion.

This study investigates dust emission potential following fire-induced de-vegetation in the driest region of the world’s largest sand sea, the southwest Kalahari. Adopting a hybrid approach, we combine remote sensing to characterise fire extent and timing and portable wind tunnel (PI-SWERL) experiments to quantify erosion potential.

A 24-year fire inventory reveals that burning is most frequent during or immediately after La Niña events, although anthropogenic land management significantly influences the spatial and temporal distribution of fires. The period for dust emission potential following fire is short, constrained by rapid vegetation recovery typically within 2 years. Grain size analyses indicate that dust-sized particles (<62.5 μm) are present in both burned and unburned dune surfaces; however, no significant depletion of fine particles from burned surfaces was observed, suggesting minimal loss through aeolian processes.

PI-SWERL experiments confirm that these fine particles can be entrained, yet higher threshold friction velocities are required for erosion at burned sites. The presence of biological soil crusts (biocrust) at all burned sites implies a stabilising influence on the erosion threshold. Where the surface had been disturbed, resulting in the removal of the typically present biocrust, our data suggest that dust emission fluxes are, on average, 8-13 times higher than those of unburned surfaces.

These findings indicate that currently there is little potential for dust emission in the post-fire de-vegetation period. This study provides new insights into the mechanisms controlling dust emissions in partially vegetated dune landscapes and highlights the importance of multiple, interacting, surface properties in governing aeolian processes.

How to cite: Huck, R., Wiggs, G., Thomas, D., and Wallum, N.: Re-evaluating Dust Emission Potential from Burned Surfaces on Vegetated Dunes in the Southwest Kalahari, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5689, https://doi.org/10.5194/egusphere-egu26-5689, 2026.

EGU26-5689

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West Africa is a key region for the transport and deposition of Saharan mineral dust, with major impacts on air quality, climate, and ecosystems. Dust sources are numerous within the Sahara and their spatial extent remains poorly constrained, as do their granulometric, mineralogical, and chemical characteristics, which however control their impacts. Moreover, emission maps available in the literature do not allow the relative contribution of different source regions to a given impacted area to be assessed.

This study proposes a sink-to-source reverse approach aimed at improving the characterization of dust emission areas affecting the coastal West Africa. It is based on a three-year time series of PM₁₀ concentrations measured in Casamance, southern Senegal, a region under the influence of easterly winds (Harmattan) responsible for the transport of Saharan dust in the lower troposphere during the dry season. The measurements were conducted at a rural site (Pointe Saint Georges), minimally influenced by local and anthropogenic emissions.

PM₁₀ concentrations were coupled with air mass back-trajectories calculated using the HYSPLIT model and analyzed with the ZeFir software in order to identify potential source regions. Preliminary results suggest that, during high PM₁₀ concentration events observed along the West African coast, dust derived from two dominant sectors : one to the north-east including areas in Mauritania and across the Algerian-Mali border, and one to the east across the Sahelian region, confirming earlier findings (Le Quilleuc et al., 2021, JGR, doi.org/10.1029/2021JD035030). These results will be discussed in the light of emission areas provided by the satellite-based IDDI (Infrared Difference Dust Index) product as well as data on dust sources from the literature.

The results that will be presented highlight the potential of this sink-to-source approach for identifying mineral dust source areas based on airborne concentrations. This methodology, relying on low-cost sensors, is reproducible and applicable to any site located downwind of desert regions.

Keywords : PM₁₀, Saharan dust, Casamance, Senegal, air mass back-trajectories, HYSPLIT, ZeFir software, IDDI, sources

How to cite: Bassene, M. M. A., Bory, A., Camara, M., Derimian, Y., Petit, J.-E., Rajot, J.-L., Marticorena, B., Verfaille, L., Yock, D., Sambou, F., Ndiaye, T. M., Diallo, A., and Roumazeilles, V.: A sink-to-source reverse approach to identify dust source regions within the Sahara based on PM₁₀ levels measured on the West African coast, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18712, https://doi.org/10.5194/egusphere-egu26-18712, 2026.

EGU26-18712

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Coarse mineral dust aerosols originating from arid and semi-arid regions worldwide constitute one of the dominant tropospheric aerosol species by mass. Mineral dust both absorbs and scatters solar and terrestrial radiation, thereby influencing the radiance spectrum at the surface and at the top of the atmosphere, as well as the atmospheric heating rate. Dust is a key, yet still highly uncertain, contributor to both historical and contemporary climate change.

Modelling the interaction of dust with atmospheric radiation remains challenging because dust absorption and scattering properties, represented by the complex refractive index, depend on mineralogical composition – which varies with the emission source – and on particle size distribution, which evolves during transport. Climate models and remote-sensing retrievals therefore require accurate, regionally dependent information to improve dust representation and reduce uncertainties in radiative effect estimates.

Laboratory investigation has proven to be a powerful approach for unravelling the optical properties of mineral dust across the solar and terrestrial infrared spectrum. Original experiments based on realistic aerosols generated from natural soils have provided important new insights into the optical properties of global mineral dust in the solar and thermal infrared spectral ranges, as well as their variability with particle composition and during transport. These results have motivated the modelling and remote-sensing communities to revisit dust representation in models, leading to new evaluations of the dust direct radiative effect and its associated uncertainty, as well as to the development of innovative remote-sensing products. Current research is now extending the investigated spectral range toward the far infrared and to emerging source regions, for which knowledge of dust–radiation interactions remains very limited.

This presentation highlights key results and open scientific questions that have driven recent research on the radiative properties of mineral dust, and outlines perspectives for future studies.

How to cite: Di Biagio, C., Sellitto, P., Picquet-Varrault, B., Doussin, J.-F., and Formenti, P.: Laboratory investigation of the radiative properties of mineral dust across the solar and terrestrial spectrum: key achievements and future directions, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9453, https://doi.org/10.5194/egusphere-egu26-9453, 2026.

EGU26-9453

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 Mineral dust deposited on snow surfaces plays an important role in snow and ice melting by reducing surface albedo and modifying surface energy balance. In addition to its direct radiative effects, mineral dust can indirectly enhance snow surface darkening by supplying nutrients that stimulate snow algal activity. Despite its importance, the sources and mineralogical characteristics of dust preserved in alpine snowpacks remain insufficiently constrained, particularly with respect to seasonal changes during the melt period.

 Most previous studies have interpreted mineral dust on snow as long-range transported material originating from continental desert regions. In alpine environments, however, progressive snow retreat during the melt season exposes surrounding ground surfaces and bedrock, potentially increasing contributions from locally derived mineral particles. How these local and remote dust sources vary seasonally, and how they are recorded in the mineralogical composition of snow-surface particles, remains poorly understood. This study aims to clarify the seasonal and spatial variability of mineral dust sources on alpine snow surfaces in the central Japanese mountains.

 We analyzed mineral particles deposited on snow surfaces in the Tateyama Mountains, central Japanese Alps. Surface snow samples collected during the melt season (May–July 2017) were compared with dust-layer samples from a snow pit excavated in April 2008, representing springtime deposition. Mineralogical analyses using X-ray diffraction and optical microscopy show that dust deposited in April and during the early melt season is dominated by quartz and feldspar, consistent with long-range transported mineral dust. As the melt season progressed, the relative abundances of Fe–Mg–bearing minerals, including chlorite, biotite, and amphibole, increased systematically. Spatial variations further reveal localized feldspar enrichment at specific sites, indicating increasing inputs from locally derived mineral particles sourced from surrounding bedrock.

 These results demonstrate a pronounced seasonal shift in mineral dust provenance on alpine snow surfaces, from dominantly long-range transported dust in spring to increasing local geological contributions during the melt season. Such changes in mineralogical composition may alter snow surface albedo and melt processes, highlighting the need to consider mineral dust composition, not only dust loading, when evaluating alpine snowmelt dynamics.

How to cite: Ataka, P., Sugiyama, R., Furukawa, N., and Takeuchi, N.: Seasonal variability of mineral dust composition on an alpine snowpack in the Tateyama Mountains, Japan , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3933, https://doi.org/10.5194/egusphere-egu26-3933, 2026.

EGU26-3933

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Aerosols over the Indian region exhibi large spatial and seasonal Variation, however long-term ground-based Measurements that can consistently illustrate these variations are still limited. In this work, I utilize Level-2 AERONET data from selected locations in India to investigate how aerosol loading and optical attributes have changed during the last decade. The analysis centers chiefly on on Aerosol Optical Depth (AOD), Ångström exponent, and basic inversion products that help identify the dominant aerosol types.

The results indicate a clear seasonal variation at all stations. High AOD values appear during the pre-monsoon months, which is consistent with dust-laden air mass intrusion from arid regions, while winter months present increased fine-mode aerosols linked to vegetation fires and area-specific emission activities. Stations located in the Indo-Gangetic Plain exhibit the highest overall AOD levels, whereas coastal and semi-arid stations demonstrate lower values and more mixed aerosol regimes. Some sites indicate a gradual rise in fine-mode aerosol contribution, suggesting increasing anthropogenic influence, while others show small or no long-term trends.

These observations assist into better understand the aerosol environment over India and also furnish a reliable reference for measuring satellite retrievals. The study highlights how AERONET measurements can support regional climate and air-quality assessments by offering consistent, long-term optical property data that cannot be captured fully by satellites alone.

How to cite: Saxena, A.: Aerosol Characteristics over India Based on Long-Term AERONET Measurements, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-261, https://doi.org/10.5194/egusphere-egu26-261, 2026.

EGU26-261

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The chemical and physical properties of atmospheric mineral dust play a key role in determining its climatic and environmental effects. These properties also vary globally, highlighting the importance of observational studies and regional investigations in enhancing global models. One of the major global dusty regions is Central-East Asia, where severe dust events occur frequently. It also hosts the largest terrestrial mineral dust record on Earth, the Chinese Loess Plateau (CLP), where dust has been deposited over the past 2.6 million years and beyond. The CLP region thus offers a globally unique archive to investigate the role of dust in both past and present climate states.

In this ongoing project, dust was collected in 2019–2021 by passive and active dust samplers from a total of six locations across the CLP region. Active collectors were placed at the Lanzhou University Semi-Arid Climate and Environment Observatory (SACOL; Gansu) and in the Shapotou District of Zhongwei (Ningxia) in the southeastern margin of the Tengger Desert. Passive samplers were placed at SACOL, Lingtai (Gansu), Yinchuan (Ningxia), Luochuan (Shaanxi), and Fugu (Shaanxi).

Grain size distributions and grain shape parameters (e.g., circularity, convexity, elongation) were measured simultaneously by Dynamic Image Analysis (DIA), while magnetic susceptibility measurements were also applied to the samples. The mineralogy of different size fractions was analysed using a single grain approach by Raman spectroscopy in the 2–10, 10–20, 20–63, and >63 µm grain size windows. Future investigations will include X-ray diffraction mineralogical analysis of the <2 µm fraction.

Temporal variations with up to daily resolution of the above-mentioned dust properties were studied from the Shapotou site, and initial magnetic susceptibility analyses suggest a change in the iron oxide composition and/or grain size during a severe dust storm event in March 2021. Future analyses will combine dust source contribution modelling and sedimentological dust provenance studies to better understand the dust cycle in Central-East Asia and its driving forces. We will also use the information on the modern dust properties and provenance to enhance understanding of the past Central-East Asian dust cycle during varying global climate states in Earth’s history and during the formation of the CLP. These include periods of warmer global climates that can be considered analogous to future conditions on our planet.

How to cite: Bohm, K., Tang, H., Wang, B., Andò, S., Kaakinen, A., Stevens, T., Salminen, J., Haugvaldstad, O., Garzanti, E., and Bi, J.: Size-resolved mineralogy and grain size-shape analysis of airborne and deposited mineral dust in northern China, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16641, https://doi.org/10.5194/egusphere-egu26-16641, 2026.

EGU26-16641

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Mineral dust, emitted from soils in arid regions by wind erosion, represents one of the largest fractions of atmospheric aerosol by mass. Once airborne, dust can travel thousands of kilometers, influencing the atmosphere through scattering and absorption of sunlight, acting as ice-nucleating particles, and depositing on the ground where it reduces snow albedo and delivers nutrients to remote regions. High-altitude mountain stations provide a unique opportunity to study dust in the free troposphere and its long-range transport.

The Sonnblick Observatory (3106 m a.s.l.), located on the main ridge of the Austrian Alps, receives dust, particularly from Northern Africa, throughout the year. In this study, we focus on selected dust events during 2024, a year of particular interest due to one of the most intense events (aerosol mass above 700 µg/m³, 30 min averages) detected at the observatory. The observatory is a Global Atmosphere Watch (GAW) station, an Aerosol, Clouds, and Trace Gases Research Infrastructure (ACTRIS) aerosol in situ national facility and hosts a variety of aerosol, cloud and meteorological measurements.

Saharan dust events (SDEs) are initially identified using the “Saharan Dust Event Index,” routinely derived from in-situ optical measurements (nephelometer and aethalometer) at the station (Schauer et al. 2016). In addition, positive matrix factorization (PMF) of in-situ aerosol data is applied, with one significant factor interpreted as mineral dust and used for a second, independent event identification. PMF highlights events that may not be captured by the Saharan Dust Index, illustrating its potential as a complementary approach for dust detection. Individual events are further characterized using the full suite of in-situ measurements and weekly offline chemical composition analyses (inorganic ions, selected elements and carbohydrates as well as elemental and organic carbon) of PM₁₀ filter samples, again combined with PMF analysis to identify major aerosol sources. Particle size distributions up to 100 µm during SDEs are retrieved from multiple instruments, including a mobility spectrometer, optical particle counter, and holographic measurements (SwisensPoleno Jupiter). Average size distributions are calculated for each event. Meteorological and atmospheric conditions are analyzed in relation to particle size distributions and optical properties. Particular attention is given to events identified solely by PMF.

Typical transport pathways are investigated using FLEXPART, and dust concentrations are simulated with WRF-Chem (Weather Research and Forecasting (WRF) model coupled with Chemistry) and compared with in-situ observations. The WRF-Chem simulation considers only dust emissions, generated by the AFWA (Air Force Weather Agency) dust emission scheme. Hourly-resolved surface dust concentration, vertically resolved dust concentration profiles, and dust load are available on a 0.2° x 0.2° latitude-longitude grid. The data also contribute to the Sand and Dust Storms Warning Advisory and Assessment System (SDS-WAS) model ensemble.

We summarize a full season of observed dust events, identify their characteristic features and develop a data analysis strategy applicable to longer time periods. In particular, we examine PMF analysis as a potential tool for SDE detection.

Schauer, G., Kasper-Giebl, A. and Mocnik, G. (2016); https://doi.org/10.4209/aaqr.2015.05.0337

Acknowledgements
The participation of A. Skiba was supported by the program “Excellence Initiative – Research University” for the AGH University of Krakow (ID:13958).

How to cite: Schauer, G., Scherllin Pirscher, B., Skiba, A., Bachleitner, T., Baumann-Stanzer, K., Kasper-Giebl, A., and Burkart, J.: Selected Mineral Dust Events at the Sonnblick Observatory in 2024: Identification and Characterization Using In-Situ Data, PMF analysis and Atmospheric Transport Modelling, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20205, https://doi.org/10.5194/egusphere-egu26-20205, 2026.

EGU26-20205

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Southern Africa (SAf) is a key region for dust emissions, characterised by a wide variety of natural and anthropogenic sources, but also a critical knowledge gap in the mineral dust budget of the Southern Hemisphere. Projected climate warming is expected to lead to an increase in mineral dust emissions, which are increasingly linked to human activity. Although the transport and deposition pathways of SAf dust suggest that it can directly affect the regional climate and nearby marine ecosystems through dust-aerosol interaction and indirectly through aerosol-cloud/ice interaction and nutrient deposition, the extent of this impact is highly uncertain due to significant uncertainties in atmospheric loads and climate-relevant properties.

This study provides the first comprehensive characterisation of the chemical and mineralogical composition of SAf dust aerosols. Aerosol samples were laboratory-generated using soils collected from key dust sources in southern Africa, including the Namib gravel plain, coastal ephemeral riverbeds, the Etosha salt pan, the Kalahari Desert, and anthropogenic sources such as agricultural soils from the Free State, savannah soils from the Kruger National Park, and a copper mine in Namibia.

A geographical distribution of the chemical and mineralogical properties of SAf dust was identified based on the elemental ratios Si/Al, (Ca + Mg)/Al, and K/Al. This is influenced by both the regional geology and rainfall distribution, which shows an increase in the Si/Al ratio and a decrease in the (Ca + Mg)/Al and K/Al ratios, in areas with higher rainfall inland compared to the arid coast, while the salt pans exhibit unique features with significantly higher (Ca+Mg)/Al and Si/Al ratios.

The SAf dust appears to be more enriched in Ca, Mg, and K than other dust sources in the Southern Hemisphere and northern African dust. Although Fe, a key micronutrient, occurs at similar levels in dust from both hemispheres, SAf dust contains more P, highlighting its potential significance in biogeochemical cycling. Despite limited mineralogical observations in the Southern Hemisphere, our results indicate that SAf dust contains more feldspar minerals than northern African dust, and may strongly influence the load of ice-nucleating particles over the Southern Ocean and, in turn, the regional radiative budget.

How to cite: Baldo, C., Nowak, S., Chevaillier, S., Noyalet, G., Becagli, S., Ito, A., Lafon, S., Di Biagio, C., Desboeufs, K., Stanus, R., Mattielli, N., Vos, H. C., Okin, G. S., King, J. S., Chaput, A., Language, B., Piketh, S., and Formenti, P.: The chemical and mineralogical composition of southern African dust aerosols, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12288, https://doi.org/10.5194/egusphere-egu26-12288, 2026.

EGU26-12288

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Mineral dust is a key component of Earth’s climate system; it influences the global radiation budget, fertilises ecosystems, and constitutes a threat to human health. Accumulation of windblown dust in marine archives provides a means to assess past change in Earth’s continental hydroclimate. However, interpretations of these records are often undermined by an attribution problem: the uncertainty of provenance. Here we report new radiogenic isotope data (Sr, Nd, and Pb) from unconsolidated surface sediments sampled from active dust sources and integrate them with published geochemical and satellite-derived datasets (such as dust source activation frequency (DSAF)) to define preferential source areas (PSAs) across the Northern Hemisphere dust belt. Our analysis shows that pairing Pb with Nd or Sr isotope data allows clearer discrimination between source regions that overlap in Nd-Sr space. We also show that Pb data are particularly helpful to discriminate between sources when presented as D²⁰⁷Pb/²⁰⁴Pb and D²⁰⁸Pb/²⁰⁴Pb: deviations of Pb from the Northern Hemisphere Reference Line (NHRL) that defines the Pb isotopic evolution of the Northern Hemisphere’s mantle. Comparison with published Pb isotope data reveals major limitations in spatial coverage and suggests that application of more consistent cleaning protocols is merited including removal of anthropogenic Pb. Nevertheless, our new data help to discriminate among the dust sources of East Africa and Western Asia more clearly than before, improving our ability to interpret past continental hydroclimate change recorded in marine sediment cores from the northern Indian Ocean.

How to cite: Howcroft, D., Crocker, A., Taylor, R., Michalik, A., Milton, J. A., Drake, N., Breeze, P., Keir, D., Petraglia, M., Jotheri, J., Jha, D., and Wilson, P.: The Pb, Nd, and Sr isotopic characterisation of dust sources in North Africa and Western Asia., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19688, https://doi.org/10.5194/egusphere-egu26-19688, 2026.

EGU26-19688

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Mineral dust is a key component of the globally-emitted aerosol mass. Although, mineral dust mixes with anthropogenic pollution during its atmospheric lifetime, data on polluted mineral dust layers have been scarce.

In April 2017, the A-LIFE aircraft field experiment (www.a-life.at) was carried out in the Eastern Mediterranean. A-LIFE combined ground-based, airborne, satellite, and modelling efforts to characterize mineral dust mixtures with unprecedented detail. In 22 research flights (~80 flight hours), outbreaks of Saharan and Arabian dust, as well as pollution, biomass burning, and dust-impacted clouds were studied, and a unique aerosol and cloud data set was collected. Aerosol source apportionment was achieved with the Lagrangian transport and dispersion model FLEXPART version 8.2. Based on FLEXPART model results and aerosol measurements, the observations were classified into 12 aerosol types consisting of four main aerosol types (Saharan dust, Arabian dust, mixtures with and without coarse mode). Each of the four main aerosol types was further separated into three sub-classes (clean, moderately-polluted and polluted). For each of the 12 aerosol classes, microphysical and optical aerosol properties were derived.

For the first time, the effect of pollution on the microphysical and optical properties of Saharan and Arabian dust was investigated systematically, revealing significant changes as a function of pollution content. The particle size distribution changes as a function of pollution content with effective diameters systematically decreasing for increasing pollution content. The collected data also provide new insights into the impact of Saharan and Arabian dust on cloud evolution processes, atmospheric radiation budget, and local meteorology. One outstanding finding of A-LIFE is that scattering properties of polluted dust mixtures do not show the typical dust signature, but rather show a wavelength-dependency of the scattering coefficient which is typical for pollution. This means that optical properties of mineral mixtures are frequently dominated by the pollution.

In this presentation, we will show the results of the A-LIFE project including its mission objectives, experimental design, and meteorological conditions; highlight major A-LIFE findings; and feature the available data products on the optical, microphysical, and hygroscopic properties of pure and polluted mineral dust.

How to cite: Weinzierl, B., Dollner, M., Gasteiger, J., Teri, M., Schöberl, M., Heimerl, K., Tipka, A., Seibert, P., Huntrieser, H., Wagner, R., Kandler, K., Sudharaj, A., Müller, T., Brilke, S., Fölker, N., Sauer, D., Reitebuch, O., Groß, S., Freudenthaler, V., and Toledano, C. and the A-LIFE Science Team: The A-LIFE aircraft field experiment in the Eastern Mediterranean: what have we learned about mineral dust mixtures?, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21358, https://doi.org/10.5194/egusphere-egu26-21358, 2026.

EGU26-21358

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Atmospheric dust affects the Earth’s radiation budget through scattering and absorption, processes governed by its optical properties linked to their microphysical characteristics (size, shape, refractive index, and orientation). While knowledge of dust particle size has progressed in the last few decades, dust morphology remains poorly constrained beyond the generic category of “irregular particles”. Although some studies suggest that dust particles can exhibit preferred orientations within the atmospheric column, most radiative-transfer models still represent dust as ensembles of randomly oriented spheres or spheroids. The limited availability of direct observational evidence limits our understanding of how dust’s non-sphericity and orientation influence remote-sensing retrievals, atmospheric processes, and aerosol radiative forcing. Given that mineral dust accounts for one of the largest global mass fluxes of primary aerosols, reducing these uncertainties is crucial to better constrain its overall radiative impact.

To address these gaps, we collect new UAV-based datasets on dust particle shape, internal structure, and orientation. In spring 2025, the Cyprus Institute conducted a two-month UAV campaign aiming for two goals: (1) to advance airborne dust-sampling methods, and (2) to investigate dust composition, size, shape, and orientation. Multiple UAV platforms were deployed during eight dust-affected flight days, guided by daily dust and weather forecasts. This strategy enabled sampling of diverse atmospheric conditions, including a strong dust event on 17/05/2025 with total AOD at 500- nm approaching the value of 1. Additional campaigns will further expand the dataset.

The UAV payloads included the Compact Optical Backscatter Aerosol Detector (COBALD) and Giant Particle Collectors (GPAC), supplemented by Optical Particle Counters (OPCs). To detect signatures of particle orientation two COBALD instruments, each operating at two wavelengths (455 and 940 nm), were deployed in a dual-field-of-view configuration pointing horizontally and vertically with two nearly orthogonal viewing directions. GPAC were adapted to carry TEM grids (small, ultra-thin mesh substrates used to collect particles for transmission electron microscopy) enabling airborne dust sampling suitable for high-resolution imaging and 3-D reconstruction of particle morphology. These combined measurements provided a unique dataset for assessing dust particle morphology, size, and potential orientation effects in the atmospheric column.

How to cite: Tschorn, K. M., Kandler, K., Wienhold, F. G., Kezoudi, M., Papetta, A., Fragkos, K., Schneiders, K., Bona, Z., and Marenco, F.: UAV observations to reveal new insights into dust particle morphology and orientation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-943, https://doi.org/10.5194/egusphere-egu26-943, 2026.

EGU26-943

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Keywords: Mass Spectrometry, Real-Time, Trace Elements, Source Apportionment, Mobile

Determination of the elemental composition of airborne nanoparticles and micro-particles is essential to understand the source(s) of these particles and also to predict potential health effects.¹ The most common approach to measure the metal content of air is to collect samples on filters and then analyze digests by ICP-MS; however, this strategy offers poor time resolution (e.g. days) and only provides bulk element composition information. To understand the spatiotemporal characteristics of the emission of metal-containing aerosols, which is key to assessing exposure, real-time analysis strategies are essential. Here, we report on the development of a microwave induced plasma time-of-flight mass spectrometer (mipTOF) used for the direct analysis of metal-containing airborne particles.

The mipTOF is a field-deployable trace-element mass spectrometer. It uses a nitrogen-sustained high-power plasma (MICAP, Radom Instruments)^{2, 3} to quantitatively vaporize and atomize aerosols with sizes from the ultrafine to PM10. Singly charged atomic ions are generated in the plasma with high efficiency (up to 99%), and then extracted into the mass spectrometer, where they are sorted according to mass-to-charge ratio and recorded. Ambient air is sampled into the plasma via a concentric pneumatic nebulizer set up as a Venturi pump⁵ at flowrates from 100-200 cm³/min. With the mipTOF, concentration LODs range from 10 ng/m³ (potassium) to 0.05 ng/m³ (lead) with a time resolution of 10 seconds. The high-sensitivity, high-speed metal-aerosol measurements possible with mipTOF enable new research into real-time spatiotemporal analysis of metals in air. We will report on the use of the mipTOF in mobile lab measurements in Switzerland and Massachusetts, USA. In these measurements, we identified several unique sources of airborne metals, including emissions from automotive brake wear, trains, metal-plating industries, cement manufacturers, and light aircraft. In addition to presenting data from these campaigns, we will discuss aspects of instrument design and operation, including power and size requirements, calibration strategies, and instrumental figures of merit.

References:

(1) Daellenbach, K. R. et al. Nature 2020, 587 (7834), 414-419.

(2) Jevtic, J.; Menon, A.; Pikelja, V. PCT/US14/24306, 2015.

(3) Schild, M. et al.  Analytical Chemistry 2018, 90 (22), 13443-13450.

(4) Nishiguchi, K.; Utani, K.; Fujimori, E. J. Anal. Atom. Spec. 2008, 23 (8), 1125-1129.

How to cite: Tanner, M., Gundlach-Graham, A., Rittner, M., Gfeller, L., Slowik, J., Prevot, A., Fortner, E., and Jayne, J.: Real-time analysis of trace metals in air by microwave induced plasma time-of-flight mass spectrometry (mipTOF), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7724, https://doi.org/10.5194/egusphere-egu26-7724, 2026.

EGU26-7724

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How to cite: Reid, D., Aplin, K., and Teanby, N.: Experimental Characterisation of the Electric and Magnetic Fields Generated by Dust Devils , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19364, https://doi.org/10.5194/egusphere-egu26-19364, 2026.

EGU26-19364

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Clouds with temperatures between −39° and 0 °C can be capped by either a liquid or an ice layer, strongly influencing their radiative forcing and precipitation. The cloud-top ice-to-total frequency (ITF) quantifies the occurrence of clouds with ice tops relative to all clouds, yet the processes controlling ITF remain poorly understood. Using 35 years of satellite observations (Cloud_cci v3) and dust reanalysis (MERRA2), we show that in the Northern Hemisphere, at temperatures between −15° and −30 °C, ITF is strongly correlated with dust aerosol variability in both time and space. Moreover, we find that the sensitivities of ITF to temperature and dust occur in a ratio consistent with laboratory measurements of immersion droplet freezing, indicating that dust aerosols impose a logarithmic control on cloud-top phase.

How to cite: Villanueva, D., Stengel, M., Hoose, C., Jeggle, K., Bruno, O., Ansmann, A., and Lohmann, U.: Dust-driven droplet freezing explains cloud-top phase in the northern extratropics., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11564, https://doi.org/10.5194/egusphere-egu26-11564, 2026.

EGU26-11564

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In the temperature range between 0 °C and −39 °C, clouds may exist in the liquid phase, the ice phase, or as a mixture of both. Cloud glaciation, defined as the transition from liquid to ice, can be driven by multiple processes. On the one hand, enhanced glaciation may result from secondary ice production. On the other hand, atmospheric aerosols can act as ice-nucleating particles (INPs) and initiate ice crystal formation. Previous studies have highlighted the role of mineral dust as the dominant INP source for cloud glaciation at temperatures below −15 °C.

Although recent findings indicate a correlation between aerosol concentration and cloud glaciation, quantifying aerosol–cloud interactions remains challenging. To better characterize and disentangle the natural spatial and temporal variability of relevant observables governing this relationship, this study combines data from multiple satellite instruments (MSG SEVIRI, MODIS, and IASI). In addition, these observations are compared to ICON model outputs and CAMS reanalysis data. The objective is to provide an assessment of the sensitivity of cloud phase to dust aerosol concentration for given temperatures and synoptic conditions across different datasets.

We primarily investigate the influence of the dust aerosol optical depth (DAOD) in the region between the equator and the subtropical dust belt (0–30° N/S). Our findings highlight the relationship between DAOD and cloud glaciation, characterized by a particularly strong increase in glaciation at high DAOD values. The analysis further includes stratification by large-scale synoptic conditions and cloud type, allowing us to narrow down potential differences between convective and stratiform clouds.

Finally, we examine how the integration of vertical profiles from EarthCARE may facilitate the detection of not only horizontally but also vertically collocated cloud and aerosol layers, thereby improving statistical estimates of aerosol–cloud interactions.

How to cite: Brüning, S., Stengel, M., and Robbins, D.: Investigating dust aerosol effects on mixed-phase cloud glaciation based on an intercomparison of satellite observations, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12744, https://doi.org/10.5194/egusphere-egu26-12744, 2026.

EGU26-12744

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In the atmosphere, organic and inorganic compounds can partition into clouds, fog, raindrops, and aqueous aerosols, where they undergo rapid chemical oxidation, yielding secondary aerosols. This process is governed by the availability of radicals such as hydroxyl (OH) and nitrate (NO₃) radicals in the liquid phase. The presence of dissolved iron can boost the OH reactivity via Fenton reactions. Dust is a major source of iron in the atmosphere, occurring primarily in the crystalline lattices of aluminosilicates or as iron oxides. Following its emission, iron tends to be mostly insoluble but can be converted into soluble forms when inorganic acids decrease the pH, and organic ligands create iron complexes during atmospheric transport. In this study, we address the importance of iron in global atmospheric oxidation processes by mechanistically modelling the related chemical processes in the gas and liquid phases within clouds, fog, rain droplets, and, for the first time, aqueous aerosols. We employ the atmospheric chemistry MESSy model infrastructure, coupled to the global general circulation model ECHAM5 (EMAC). We represent three mechanisms of iron dissolution into aerosol water, driven by aerosol acidity, irradiation, and the presence of oxalate in the solution, which acts as an organic ligand. In the atmosphere, oxalate is the dominant dicarboxylic acid, mainly formed via aqueous-phase oxidation of glyoxal and other organic compounds. Our new approach is to explicitly account for oxalate-related aqueous-phase chemistry. Through a series of sensitivity simulations, with and without soluble iron, we address the global impact of iron on aqueous-phase oxidation capacity. We find that iron uptake into aerosol water enhances OH reactivity, particularly in cloud droplets, thereby increasing the aqueous oxidation of isoprene oxidation products and influencing secondary organic aerosol formation.

How to cite: Rosanka, S., Klingmüller, K., Sander, R., Pozzer, A., Lelieveld, J., and Taraborrelli, D.: Impact of iron-containing dust on atmospheric oxidation processes, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13178, https://doi.org/10.5194/egusphere-egu26-13178, 2026.

EGU26-13178

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Atmospheric deposition of aerosols constitutes a major source of iron and other micronutrients to remote ocean regions, where nutrient limitation constrains primary productivity and carbon sequestration. However, large uncertainties persist due to sparse observational data and the lack of sensitive techniques capable of resolving metal solubility at low aerosol loadings. Here we present first results from a shipborne campaign conducted aboard R/V Sonne across the Indian Ocean in late 2024 within the framework of the GEOTRACES program.

Aerosol particles were characterized using a novel single-particle mass spectrometer (SPMS) employing resonant laser ionization, enabling the analysis of the chemical composition of several hundred thousand individual particles. While sea spray aerosols dominated the overall particle population, thousands of iron-containing particles were detected, primarily associated with long-range transported mineral dust. Notably, a subset of sea spray aerosol particles exhibited detectable iron signals, suggesting in-cloud mixing or surface re-emission processes as potential sources.

For mineral dust particles, nitrate represented the dominant secondary component even in air masses without continental influence for more than ten days. Elevated iron contents within dust particles frequently coincided with the presence of dicarboxylic acids, whereas Mg/Ca-rich particles were preferentially associated with sulfate, indicating distinct atmospheric processing pathways, transport histories, and likely differences in iron solubility. By resolving such internal mixtures at the single-particle level, the SPMS provides a powerful approach for source attribution and for assessing the potential bioavailability of aerosol-derived metals. These observations reveal an unexpectedly high abundance and chemical diversity of iron-containing aerosols over the Indian Ocean, underscoring their importance for ocean biogeochemistry and nutrient cycling in this understudied region.

How to cite: Passig, J., Kalamašņikovs, A., Hakkim, H., Irsig, R., Ehlert, S., Walte, A., Achterberg, E., and Zimmermann, R.: Trace metal-containing aerosols in the atmosphere of the Indian Ocean, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14701, https://doi.org/10.5194/egusphere-egu26-14701, 2026.

EGU26-14701

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At a global scale, dust can serve as a vector for transferring elements from nutrient-rich soils to nutrient-depleted ecosystems, acting as a natural fertilizer [1]. The Amazonian rainforest, which is partly developed over nutrient-poor lateritic soils, illustrates this concept by receiving annually 8.5 Tg of dust from North African regions [2]. This phenomenon is well-documented and captured by both satellite-derived and in situ observations; however, the documentation of the long-term dust sources in North Africa and their associated chemical composition remains debated today [3,4]. This study presents two chronicles of dust collected at the Atmospheric Tall Tower Observatory (ATTO) during the dust-active season (February to April) in 2016 and 2017. Following a chemical extraction procedure already reported elsewhere [5], the chemical compositions and Sr-Nd-Pb isotope signatures of samples collected during low-dust conditions and dust outbreak events have been analyzed.

Following a statistical ACP and clustering analysis, the extracted water-soluble, acid-soluble, and residual fractions show that dust loading is the main driver of aerosol composition. Carbonated minerals do not survive efficiently in the atmospheric conditions encountered during transatlantic transport within the Saharan Air Layer and are readily solubilized. Most of the silicates and oxides are resistant to atmospheric chemical weathering, with the exception of poorly crystallized Al-Fe oxides. Finally, the geochemical signals of trace metals, potassium, and phosphorus can be complicated by anthropogenic particles or emitted bioaerosols, in addition to dust.

Predominant north African dust sources are identified by combining rare earth element patterns with Sr-Nd-Pb radiogenic isotopes, both of which are clearly diagnostic. A Bayesian mixing model (MixSIAR) is also used to quantify the long-term proportion of each source, while satellite products (CALIPSO, MERRA-2) and back trajectory analyses (HYSPLIT) are used to confirm our observations. Western African soils characterized by alluvial deposits in wadis developed over Phanerozoic terrains are the dominant dust sources (55-90%), while soils associated with Precambrian cratonic areas can act sporadically during significant dust events. As already postulated using a satellite-derived model [3], the Bodélé Depression’s impact on dust reaching the Amazon Basin is negligible, despite its status as the dustiest place on Earth. These results are consistent with conclusions drawn for the Northern Hemisphere, particularly for the Caribbean [5], although dust transport and atmospheric conditions over North Africa differ seasonally (between boreal winter and boreal summer). Finally, the chemical composition of the dust measured for all dust events reaching ATTO in 2016 and 2017 is remarkably uniform and consistent with 2024 and 2025 collected samples from French Guiana and ATTO (Collignon et al., in prep.), allowing for a preliminary estimate of a long-term “averaged North African dust” composition reaching the Amazon Basin.

[1] Reicholf (1986), SNFE, 21, 251-255.

[2] Kok et al. (2021), ACP, 21, 8169-8193.

[3] Yu et al. (2020), GRL, e2020GL088020.

[4] Barkley et al. (2022), GRL, e2021GL097344.

[5] Kumar et al. (2018), EPSL, 487, 94-105.

How to cite: Guinoiseau, D., Pöhlker, C., Kral, A., Saturno, J., Ditas, F., Artaxo, P., Andreae, M. O., and Galer, S. J. G.:  Dust source transfer from North Africa to the Amazon Basin: geochemical constraints on their long-term sources and composition , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12006, https://doi.org/10.5194/egusphere-egu26-12006, 2026.

EGU26-12006

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Desert dust is the most abundant aerosol by mass in Earth’s atmosphere (global dust loading of 22-29 Tg; [1]). One key region of interest is the Amazon Basin, which acts as a major sink for mineral dust transported from North Africa (deposition flux of ∼10 Tg.yr^-1; [1]), impacting the nutrient supply to this rainforest ecosystem [2]. Currently, Western African sources are expected to be the predominant dust source based on previous geochemical studies [3] and atmospheric modeling [4], while the contribution of the Bodélé region is highly debated [4]. However, further constraints are still needed to elucidate the nutrient bioavailability associated with dust and other aerosol types, as well as how chemical transformations may affect the dust geochemical signal during transport and continentalization.

This study focuses on simultaneous high-resolution records of North African dust episodes reaching two different South American locations from January to March 2025. The first location is a coastal observatory in French Guiana (ATMO), while the second is located in the central Amazon forest, in Brazil (ATTO). Although these observatories are separated by more than 1,000 km, they are both influenced by similar transatlantic air mass trajectories, enabling an assessment of the impact of air mass continentalization on the chemical and physical characteristics of the aerosol particles. Aerosol samples have been chemically characterized using a recently developed selective extraction protocol [3], which segregates particles into water-soluble, acid-soluble, and residual material, including the silicate fraction of dust [5].

A 65 % dust loading reduction is observed between ATMO and ATTO sites, accompanied by a decrease in the soluble fraction from 20–50 %, dominated by sea salt at ATMO, to less than 10 % at ATTO. Other constituents originate from the dissolution of carbonates (Ca, Mg) due to atmospheric processes, from the leaching of soot particles or the emission of bioaerosols (K, P), and from the partial dissolution of poorly crystallized oxides (Al, Fe).  

The silicate fraction, which dominates the aerosol mass (50-98%), reveals a remarkable stability in the elemental composition of dust, irrespective of the observatory location, the position within the dust event (onset, peak, or decay), or the meteorological conditions. This compositional consistency exhibits a highly coherent signal when compared with previous dust episodes observed in 2016, 2017, and 2024 [3]. Furthermore, isotopic signatures of Sr, Nd, and Pb, known as efficient proxies for dust sources, are in strong agreement with those measured during these earlier episodes, confirming the dominant role of the West African dust source and the negligible contribution of the Bodélé Depression. Overall, these findings underscore the robust stability of the geochemical signal carried by dust, thereby enhancing our understanding of the average dust composition that reaches the Amazon Basin. In contrast, the focus on more labile components is strategic since these elements are preferentially redistributed into the water- and acid-soluble fractions.

[1] Kok et al. (2021), https://doi.org/10.5194/acp-21-8169-2021

[2] Swap et al. (1992), https://doi.org/10.1034/j.1600-0889.1992.t01-1-00005.x

[3] Collignon et al., submitted.

[4] Yu et al. (2020), https://doi.org/10.1029/2020GL088020

[5] Kumar et al. (2018), https://doi.org/10.1016/j.epsl.2018.01.025

How to cite: Collignon, L., Guinoiseau, D., Panechou, K., Gaston, C. J., Brill, S., Galer, S. J. G., Karunanithi, S., Pohlker, C., and Quantin, C.: Unraveling the geochemical signals from major episodes of Saharan dust at two different locations in the Amazon basin., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13474, https://doi.org/10.5194/egusphere-egu26-13474, 2026.

EGU26-13474

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Saharan dust is frequently transported across the Atlantic, yet the chemical, physical, and morphological transformations dust undergoes within the marine atmospheric boundary layer (MABL) remain poorly understood. These transformations are critical for understanding dust’s radiative and geochemical impacts, it’s representation in atmospheric models, and detection via remote sensing. Here, we present coordinated observations from the Office of Naval Research’s Moisture and Aerosol Gradients/Physics of Inversion Evolution (MAGPIE) August 2023 campaign at Ragged Point, Barbados. These include vertically resolved single-particle analyses, mass concentrations of dust and sea spray, and High Spectral Resolution Lidar (HSRL) retrievals. Single-particle data show that dust within the Saharan Air Layer (SAL) remains externally mixed, with a corresponding high HSRL-derived linear depolarization ratio (LDR) at 532 nm of ~0.3. However, at lower altitudes, dust becomes internally mixed with sea spray, and under the high humidity (>80%) of the MABL undergoes hygroscopic growth, yielding more spherical particles, suppressing the LDR to <0.1; even in the presence of  high dust loadings (e.g., ~120 µg/m³). This low depolarization in the MABL is likely due to a combination of the differences between the single scattering properties of dust and spherical particles, and the potential modification of the dust optical properties from an increased hygroscopicity of dust caused by the mixing with sea salt in the humid MABL. These results highlight the importance of the aerosol particle mixing state when interpreting LDR-derived dust retrievals and estimating surface dust concentrations in satellite products and atmospheric models.

How to cite: Gaston, C., Shrestha, S., Holz, R., Marais, W., Buckholtz, Z., Razenkov, I., Eloranta, E., Reid, J., Elliott, H., Lata, N. N., Cheng, Z., China, S., Blades, E., Ortiz, A., Chewitt-Lucas, R., Allen, A., Blades, D., Agrawal, R., Reid, E., and Ruiz-Plancarte, J. and the Ragged Point MAGPIE Team: Transported African Dust in the Lower Marine Atmospheric Boundary Layer is Internally Mixed with Sea Salt Contributing to Increased Hygroscopicity and a Lower Lidar Depolarization Ratio, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13316, https://doi.org/10.5194/egusphere-egu26-13316, 2026.

EGU26-13316

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Australian aridity is primarily governed by large-scale atmospheric circulation and by the influence of the Australian-Indonesian monsoon (AIM). Regional climate variability is further modulated by coupled ocean-atmosphere modes, including the El Niño-Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), and the Southern Annular Mode (SAM), whose interactions regulate moisture supply and hydroclimatic variability across the Australian continent. Western Australia has experienced pronounced hydroclimatic variability through time, characterized by arid glacial intervals and more humid interglacials, highlighting a strong regional sensitivity to insolation forcing, large-scale atmospheric circulation, and changes in Indo-Pacific climate modes. However, Australian hydroclimate responses during intervals of major climatic reorganization, such as the Early-Middle Pleistocene Transition (EMPT), remain poorly constrained. The EMPT (~1.2-0.6 Ma) marks a fundamental reorganization of the climate system, characterized by intensified glacial-interglacial cycles and a shift toward a ~100-kyr periodicity.

Here, we present a grain size record from IODP Site U1460 spanning the EMPT, reflecting changes in aridity within western Australia. Using a grain-size end-member unmixing model, we aim to distinguish relative changes in the proportions of fine-grained material and coarser-grained sediment as proxies for shifts between humid and arid intervals. Furthermore, we are developing a specialized method to remove biogenic silica from marine sediment, as the site contains a high concentration of sponge spicules. These spicules are particularly challenging to remove due to their chemical resilience. This method is critical to prevent interference with sedimentological measurements and to ensure the accuracy of our grain size end-member modelling and hydroclimatic interpretations. Our grain size record will not only provide a refined biogenic silica removal method but also offer new insights into the evolution of Australian arid environments and the mechanisms linking regional hydroclimate to global climate reorganization during the Pleistocene. These findings will serve as critical analogues for understanding hydroclimatic sensitivity under sustained anthropogenic forcing.

How to cite: Kunkelova, T., Arrigoni, A., and Auer, G.: Aridity record from the western Australia across the Early-Middle Pleistocene Transition, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6290, https://doi.org/10.5194/egusphere-egu26-6290, 2026.

EGU26-6290

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Saharan dust input is a well-known phenomenon worldwide but especially concerning landscapes around the Mediterranean Sea and on the Canary Islands since the largest dust source areas on earth are located in the Northern African continent. This dust transport is not just a recent process but has also been going on for the last glacial period with changing intensities. The availability of dust depends mainly on the vegetation cover in the source areas as well as changing wind strengths/pathways and is therefore a function of changing climate. Its effects have been imprinted in several geoarchives and are also well known from aeolianites. These coastal dune archives typically form in dependence of changes in sea level and are comprised of pale coloured carbonate sands, intercalated by reddish silty layers. The reddish silty layers are heavily influenced by dust imprint from the Northern African continent. The presented research project hence focuses on conducting detailed analyses on those layers to reconstruct the local and supraregional environmental conditions during the last glacial.
Our sites on the eastern Canary Islands (Lanzarote, Fuerteventura), SE-Spain, Balearic Islands (Formentera, Eivissa) and Sardinia offer best conditions to
(i) Analyse site-specific characteristics of the dust enriched layers and the stored information about the local environmental conditions,
(ii) Look for differences or systematical similarities in terms of quantities and admixture of dust material when comparing the different silty layers within a single site/profile,
(iii) Identify distinct source areas of dust as well as dominating dust pathways and
(iv) Correlate the different sites from the Canary to the Tyrrhenian basin and deduce supraregional patterns.
So far we conducted extensive fieldwork at all sites and realised a variety of laboratory analyses on samples from the Balearic Islands, for example grain-size specific heavy mineral, XRF-, XRD- and grain-size analysis. With our first results we identified dust enriched layers and utilised analysis of heavy mineral compositions as an additional method to trace possible dust source areas. With this we hope to contribute to the understanding of the large-scale development in the Western Mediterranean region and the Canary Islands during the last glacial.

How to cite: Marburg, C., Gärtner, A., Schäfer, H., Schleicher, A. M., Faust, D., and Roettig, C.-B.: Late Pleistocene dust imprint in coastal dune archives spanning from the Canary to the Tyrrhenian Basin - Preliminary results, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17511, https://doi.org/10.5194/egusphere-egu26-17511, 2026.

EGU26-17511

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Palaeolithic tools preserved in the loess-palaeosol sections of southern Tajikistan as early as ~800 ka evidence the episodic presence of ancient hominins across major Quaternary climate shifts, such as the Mid-Pleistocene and Mid-Brunhes Transitions (MBT). The richest assemblage of lithic tools found in the region, the Karatau Culture, is found mainly in palaeosols associated with Marine Isotope Stages (MIS) 15, 13, and 11, with intervening glacial periods as well as previous and subsequent interglacial periods characterised by a near absence of tools, except for MIS 14 which contains a smaller number of artefacts. Curiously, the disappearance of the Karatau culture coincides with an abrupt increase in magnetic susceptibility in the palaeosol units. Currently, the cause of the alternating phases of occupation and their possible connection to wider-scale climate remain unclear.

The Khovaling Loess Plateau loess-palaeosol sequences provide an opportunity to understand the climatic and environmental context of the appearance and disappearance of early hominins. Since the Khovaling Loess Plateau is located in a transitional zone between climate systems (Mid-Latitude Westerlies, Siberian High and Indian Monsoon) regional climate may be sensitive to global climate reorganisations within the Quaternary. Based on the observed abrupt increase in magnetic susceptibility following MIS 11, it has been hypothesized that monsoon incursions may have occurred during some interglacials, and that these incursions may have ceased after MIS 11, coinciding with the disappearance of the Karatau culture. However, evidence for potential monsoon incursions is highly debated, and the cause for the change in the magnetic susceptibility record remains unclear. In this study, we apply a novel multi-frequency magnetic susceptibility approach, complemented by elemental composition data from XRF and XRD, and by paleoclimate simulations, to investigate possible variations of the hydroclimate in Central Asia. The simulations, performed with the fully-coupled HadCM3 global climate model, allow us to assess the relative and combined effects of orbital, greenhouse gas and ice sheet forcings on the hydroclimate variability including possible moisture transport pathway changes in Central Asia around MIS 13 and 11.

Based on the combined evidence, we argue that the abrupt increase in bulk magnetic susceptibility after MIS 11, observed across different sites in southern Tajikistan, is best explained by a sediment provenance change. It appears to be unrelated to any change in rainfall seasonality, and to a lesser degree, intensity. We demonstrate that relative frequency dependence of magnetic susceptibility (χ_FD %) is the most suitable proxy for calculating quantitative palaeoprecipitation estimates in this region. Our magnetic susceptibility results, calibrated against a modern-analogue based transfer function, indicate that the demise of the Karatau culture coincides with an approximate +25% increase in regional annual mean precipitation. Combined with the other proxy data, this result indicates a relatively stable regional climate across periods of hominin occupation and the MBT.

How to cite: Schneider, R., Kulakova, E., Topal, D., Almqvist, B., Buylaert, J.-P., Khormali, F., Faurschou Knudsen, M., Kurbanov, R., Sørensen, A. L., Újvári, G., Wright, D. K., Yin, Q., and Stevens, T.: Loess deposits record stable Mid-Pleistocene hydroclimate during phases of human occupation of Central Asia, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14556, https://doi.org/10.5194/egusphere-egu26-14556, 2026.

EGU26-14556

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Loess-palaeosol sequences (LPS) are vital among terrestrial archives for reconstructing Quaternary palaeoclimates and environmental change. Their extensive distribution across continental mid-latitudes and high sensitivity to atmospheric and surface processes make them indispensable records of past dust cycles, wind regimes, and regional ecosystem dynamics. However, the reliability of these reconstructions, particularly quantitative measures of dust flux variability, is intrinsically limited by the resolution and accuracy of the underlying geochronological framework. Our research directly addresses this chronometric challenge by applying refined luminescence dating techniques and Bayesian age-depth modelling to loess profiles across the Carpathian and Wallachian Basins. This methodological approach enables the construction of high-resolution, probabilistic chronologies that are essential for robust palaeoenvironmental interpretation. The central outcome of this work is a significantly improved, regional reconstruction of dust flux variability. Our integrated analysis demonstrates that dust mass accumulation rates (MARs) across the basins do not conform to a simplified model of peak deposition solely during glacial maxima (MIS 2). This pattern indicates that dust influx was not driven exclusively by global ice volume but was significantly intensified during specific phases of regional climatic amelioration. These findings compel a reinterpretation of regional atmospheric and sediment dynamics. The high dust fluxes during MIS 3 highlight the critical influence of regional controls, such as changes in palaeowind intensity and pathways, episodic sediment supply from major river systems, and the variable dust-trapping efficiency of sparsely vegetated, dynamic landscapes. This underscores the necessity of disentangling the effects of global climate drivers from those of local environmental and geomorphic settings when interpreting the LPS record. The broader objective of this synthesis is to establish a robust, integrated stratigraphic and chronological framework that enables detailed correlation and comparison of loess-derived palaeoenvironmental proxies across the Carpathian and Wallachian Basins. By doing so, we provide new insights into the timing, magnitude, and climatic forcing of past atmospheric dust activity, challenging purely glacially-driven models and contributing to a more nuanced understanding of Quaternary environmental dynamics in Central and Eastern Europe.

How to cite: Perić, Z., Marković, S., Krsmanović, P., Alexanderson, H., and Bosnić, M.: Resolving regional controls on dust flux: High-resolution chronostratigraphy of Carpathian loess, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10511, https://doi.org/10.5194/egusphere-egu26-10511, 2026.

EGU26-10511

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During the Last Glacial Maximum (LGM), global surface air temperatures were up to 6 °C lower than pre-industrial levels, and the mineral dust cycle intensified significantly, with global dust loading two to four times higher than during the Holocene. Loess deposits and Greenland ice cores record peak dust concentrations during this period. While Asian sources were traditionally considered the primary contributors to dust in Greenland, recent geochemical evidence indicates a mixture of Asian, North African, and European origins. Europe itself experienced heightened dust activity, predominantly attributed to local sources. Here, we present trace element data and Sr and Pb isotopic signatures from LGM-aged samples across 15 European sites, from a Western France to Ukraine longitudinal transect, revealing a notable contribution of fine dust from remote sources, particularly Northern Africa. These geochemical findings are corroborated by Earth System model simulations, which underscore Northern Africa's substantial role in dust deposition across the Northern Hemisphere during glacial periods.

Reference: Rousseau et al. (2025). A remote input of African dust to Last Glacial Europe. Comm. Earth & Environ., 6, 847. https://doi.org/10.1038/s43247-025-02888-9

How to cite: Rousseau, D.-D., Chauvel, C., Hopcroft, P. O., Gutiérrez, P., Saulnier-Copard, S., Antoine, P., Fuchs, M., and Ustrzycka, A.: Tracing a Northern African Contribution to European Dust During the Last Glacial Maximum, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2760, https://doi.org/10.5194/egusphere-egu26-2760, 2026.

EGU26-2760

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Asian dust plumes export micronutrients eastward to the Pacific Ocean and are substantial for regulating the marine biogeochemical cycles and productivity. Previous studies from the Gulf of Alaska (a high-nutrient and low-chlorophyll zone) revealed that the dominant nutrient supply during the last deglaciation was primarily sourced from iceberg meltwater instead of local Alaskan dust fluxes. However, attention to distal dust sources from Asia was limited, possibly due to resolution constraints. To address this, we consider here two chronologically well-constrained (by tephrochronology and radiocarbon dating) sedimentary archives from Adak Island (Andrew and Heart lakes), in the central Aleutian Islands, Alaska. These records preserve a high-resolution environmental and climatic history for the last ~10 ka and might also include a continuous record of Asian dust plume sources. Terrigenous materials in these sediments originate from either local weathered basalt units and volcanic ash or from distal Asian dust, comprising erosional products of the granitoid terrane. We studied the siliciclastic fraction of the sediments recovered from both lakes and employed elemental analyses along with radiogenic isotopes (Sr, Nd and Pb) to identify and quantify possible allochthonous dust sources. Our preliminary observations from major and trace elemental ratios and statistical analyses (PCA and factor loadings) suggest that, indeed, there are two dominant sources for terrigenous sediments. The enriched LREE and flat HREE pattern, together with a positive Eu anomaly, further support the mixed source (mafic to felsic) of the sediment supply to the lakes. Additionally, the Chemical Index of Alteration (CIA) and other elemental ratios in both lakes suggest a sharp decreasing trend ca. 4 ka followed by an increasing trend ca. 3.5 ka, which is asynchronous with the increased input of Asian dust and the neoglacial cooling event during this interval. The isotopic and other geochemical studies are in progress, which will further validate these findings.

How to cite: Rout, R. K., Ayodeji, T. J., Waldmann, N., and Palchan, D.: Tracing the provenance and evolution of Asian dust fluxes during the Holocene: A geochemical study of sediment archives from Adak Island, Alaska, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10457, https://doi.org/10.5194/egusphere-egu26-10457, 2026.

EGU26-10457

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