Posters virtual: Fri, 8 May, 14:00–18:00 | vPoster spot 4
Mesozoic Oceanic Anoxic Events (OAEs) are critical geological episodes linked to global carbon cycle perturbations, climate warming, and ecosystem restructuring. However, the regional expression of OAEs in the eastern Tethys remains insufficiently constrained. This study focuses on the Early Jurassic Toarcian OAE (T-OAE)—integrating petrological, mineralogical, and geochemical analyses of two key sections to reconstruct Early Jurassic sedimentary evolution, paleoclimate-paleoenvironment dynamics, and their responses to the T-OAE. Pronounced negative carbon isotope excursions (CIEs) are recorded in both marine strata, correlatable with global T-OAE records. Intensified continental chemical weathering and enhanced terrigenous detrital input are common responses of the eastern Tethys to T-OAE, driven by global warming. Redox proxies reveal oxic-suboxic conditions in open marine settings of the eastern Tethys during OAEs, regulated by regional factors (water depth, basin restriction, freshwater input), contrasting with the anoxic-euxinic environments in the western Tethys. Bioproductivity showed spatial heterogeneity: organic matter accumulation was controlled by redox conditions and productivity, with high accumulation in restricted lagoons versus low-moderate in open shelves.
This study reveals the regional response patterns of the eastern Tethys to Mesozoic OAEs, highlighting the spatial heterogeneity of redox and productivity dynamics, and provides new insights into the Mesozoic climate-ocean-biosphere system.
How to cite: Yi, J. and Fu, X.: Sedimentary Environment Evolution and Response to Mesozoic Toarcian Oceanic Anoxic Event (T-OAE) in the Eastern Tethys, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-279, https://doi.org/10.5194/egusphere-egu26-279, 2026.
Microbially Induced Sedimentary Structures (MISS) are syndepositional primary structures that occur both in some of the earliest forms of life and in modern environments. Throughout geological time, microorganisms developed metabolic strategies that enabled their establishment and proliferation in a wide range of settings, including arid environments such as deserts. However, MISS are widely recognized in tidal flats and other shallow-marine environments, whereas examples preserved in continental deposits remain comparatively scarce. A comprehensive review of Precambrian MISS occurrences indicates a notable expansion of documented records during the Mesoproterozoic, coincident with the assembly of the Columbia supercontinent and a concurrent rise in atmospheric oxygenation. These global transitions may have promoted the ecological diversification of microbial communities and facilitated their dispersal into progressively drier continental interiors. Under favorable conditions, microorganisms proliferate and form microbial mats that interact with external factors such as sedimentation, currents, erosional processes, and other physical drivers. Their presence in arid terrestrial deposits is thus of considerable importance, as it underscores how microbial communities evolved and developed adaptive capabilities that enabled them to colonize and persist within intermittently wet landscapes subjected to elevated environmental stress. This study documents the occurrence of MISS within continental desert depositional systems of the Mangabeira Formation, São Francisco Craton, Brazil (1.6 Ga), preserved in wet sandsheet deposits. These occurrences broaden the sparse record of MISS in Proterozoic desert environments and offer new constraints on the capacity of early microbial communities to endure highly stressful and intermittently wet conditions. To investigate the conditions that enabled microbial establishment in this ancient desert, this study applies a multi-method approach integrating sedimentological, stratigraphic, petrographic, and microtextural datasets. The vertical succession reveals six distinct drying-upward cycles, each associated with fluctuations in groundwater level that periodically generated stable, moisture-rich surfaces suitable for microbial mat development. Within these intervals, MISS occur in millimetric heterolithic laminites displaying wavy–crinkly lamination, wrinkle marks, roll-up structures, deformational features, authigenic minerals with convolute morphologies, trapped grains, and organic carbon remnants. Complementary Raman analyses reveal characteristic carbonaceous peaks (at ~1370, 1590, and 1610 cm⁻¹), confirming the presence of organic carbon and kerogen. Collectively, the integrated dataset indicates that microbial colonization in the Mangabeira Formation was episodically favored by groundwater-controlled moisture stability, which enhanced substrate cohesion and enabled the formation of distinctive biosedimentary fabrics. These findings, contextualized within the broader Mesoproterozoic expansion of MISS, highlight the capacity of early microbial communities to establish themselves in hydrologically stressed desert landscapes and refine the sedimentological and geochemical criteria necessary for recognizing MISS in deep-time continental systems.
How to cite: Feitosa, A., Bállico, M., Souza, E., Scherer, C., Callefo, F., Balbinot, V., Tatsch, G., Yokoyama, E., Leite, A., Reis, A., Silva, S., and Santos, A.: Microbially Induced Sedimentary Structures in a Mesoproterozoic Erg System: A Case Study from the Mangabeira Formation, Brazil, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-633, https://doi.org/10.5194/egusphere-egu26-633, 2026.
The middle–late Eocene climate evolution and its orbital forcing mechanisms remain poorly constrained for Qinghai-Tibet Plateau. We present a radiometrically anchored astrochronological framework and orbital-scale hydroclimate reconstruction from the Niubao Formation in central Tibet, spanning the interval between the Middle Eocene Climatic Optimum (MECO) and the Eocene–Oligocene Transition (EOT). A key tuff bed yields a zircon U–Pb age of 36.50±0.21 Ma, providing an independent tie point for stratigraphic calibration and sedimentation rate assessment. High-resolution elemental geochemistry and carbon isotope stratigraphy were analyzed using MTM spectral methods and cyclostratigraphic approaches. Proxy ratios sensitive to aridity/humidity (Sr/Cu, Al/Mg, K/Al, Sr/Ba), weathering and hydrology (Rb/Sr, Ti/K), and redox conditions (Fe/Mn) display persistent orbital pacing, with dominant periodicities at 405 kyr and 100 kyr, consistent with long and short eccentricity forcing. Across the studied interval we observe an overall trend toward more arid conditions, while eccentricity-band variability modulates hydroclimate and redox states. Carbon isotope variations facilitate correlation to coeval global records, linking central Tibetan environmental change to global Eocene climate transitions.
How to cite: Pan, G. and Fu, X.: Orbital eccentricity pacing of hydroclimate variability in Qinghai-Tibet Plateau during the middle–late Eocene, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7110, https://doi.org/10.5194/egusphere-egu26-7110, 2026.
The Makgadikgadi Basin (MKB), in the central Kalahari Basin of northeastern Botswana, currently consists of a wide complex playa lake system, a relic of the Paleolake Makgadikgadi. Reconstructing the Quaternary depositional, environmental, and climatic history of the lacustrine-playa system has great significance for revealing the basin's evolution. However, its sedimentary record remains largely unexplored due to methodological challenges. In this study, four sediment cores, up to 1.6 m deep, were collected along a generally E-W transect from the western to central parts of the Ntwetwe pan, MKB. Our multi-proxy record, including sedimentology, chronology, ostracod-based biostratigraphy, and clumped (∆47) isotope geochemistry from these cores, reveals three complex hydroclimatic sequences that refine the environmental and climatic evolution of the MKB for the past 29 cal ka BP. The computed Bayesian age depth model and preliminary clumped isotope analysis on ostracod valves suggest the late Pleistocene (~29-19.5 cal ka BP) hypersaline-saline phase occurred under relatively low temperature conditions (∆47-T = ~18.5-21°C), aligning with global glacial cooling and supporting interpretations of severe aridity in the Kalahari during the Last Glacial Maximum. The shift to a freshwater ostracod assemblage by ~5.2 cal ka BP partly corresponds to the termination of the African Humid Period (AHP), with a mean temperature (∆47-T) of ~16.8°C. However, our record reveals significant complexity during the Late Holocene. The dominance of brackish water assemblage from ~4-1.6 cal ka BP suggests a prolonged transitional phase toward aridity, consistent with the broad trend of ITCZ retreat. Most notably, the late Holocene (~1.6-1 cal ka BP) assemblage, indicating a mix of brackish and freshwater taxa alongside extreme and warmer temperatures (∆47-T = ~28.5°C). This implies a period of complex hydrological variability, potentially driven by increased summer rainfall variability or episodic flood inflow. Consequently, the Late Pleistocene and Middle Holocene data align with regional patterns, while the Late Holocene sequence particularly highlights the current extreme climate in the region, suggesting ostracod growth under extreme ephemeral playa lake conditions.
How to cite: Kahsay, T., Asrat, A., Sinha, N., Marchegiano, M., and Franchi, F.: Late Pleistocene to Holocene Multi-proxy Paleoenvironmental and Paleoclimatic Reconstruction of the Makgadikgadi Basin, Central Kalahari, Botswana, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7064, https://doi.org/10.5194/egusphere-egu26-7064, 2026.
Quantitative estimates of Holocene climate conditions have been developed since the 1960s using space‑for‑time calibration approaches. Although hundreds of reconstructions are now available globally, questions persist regarding their accuracy. We evaluate quantitative reconstructions derived from three sources: site‑specific studies, regional reconstruction compilations, and regional products generated from global databases. The focus is on Holocene pollen‑based reconstructions, which remain the most widely used indicators of terrestrial paleoclimate and on North American Arctic and treeline regions. Reconstructions developed at individual sites often display substantial high‑frequency variability, including anomalous values and abrupt shifts, reflecting in part calibration-related artifacts. Regional averages (“stacks”) reduce some of this variability, yet comparisons based on different reconstruction sources reveal divergences. Conversely, studies analyzing paired cores from a single lake or from closely spaced sites frequently demonstrate strong replication and relatively low reconstruction error. Multi‑proxy analyses of Arctic cores likewise reveal both areas of agreement and persistent discrepancies. Addressing these inconsistencies remains a challenge for Holocene climate reconstruction.
How to cite: Gajewski, K.: Analysis of quantitative pollen-based reconstructions, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-15510, https://doi.org/10.5194/egusphere-egu26-15510, 2026.
To understand the climate conditions in Japan before the commencement of modern official meteorological observations, it is necessary to indirectly estimate them using proxy data that serve as climate indicators.
In Japan, there is a nearly continuous annual dataset of Lake Suwa's freezing records spanning over 580 years. Furthermore, diaries from various parts of Japan contain daily weather records. By utilizing these records, daily climate data with the minimum temporal resolution can be obtained. By leveraging these proxies, it is possible to reconstruct the climate of the cold season, which has been previously less understood, across various temporal and spatial scales.
The objective of this study is to reconstruct the changes in cold-season climate in Japan over the past several hundred years with high temporal resolution.
The proxy data currently used include: lake and terrestrial sediments (Lake Suwa, approximately 1000 years), records of cherry blossom flowering and full bloom dates primarily collected in Kyoto (approximately 1000 years), tree rings (approximately 300 years), daily weather records from diaries (approximately 200 years), freezing records of Lake Suwa and Lake Jusan (approximately 580 and 150 years, respectively), early-meteorological observation data (approximately 50 years), and Japan Meteorological Agency observation data (approximately 150 years).
Firstly, the most extensive dataset, the cherry blossom flowering data, is used as a reference. Next, proxy variables are standardized after removing trends caused by human activities. Subsequently, regression analysis is performed for each period where variations either coincide or do not coincide. Furthermore, for each proxy variable, spatial correlations were calculated using 20th-century meteorological observation data to identify the regions represented by that proxy variable.
(This research was funded by JSPS Grant-in-Aid for Scientific Research (24H00118).
How to cite: Hasegawa, N., Katata, G., Hirano, J., Yonenobu, H., Yasue, K., Kumon, F., Hatano, N., Takahashi, H., Zaiki, M., and Mikami, T.: Reconstruction of Japan's Cold-Season Climate in the Past Few Hundred Years Using High-Resolution Multi-Proxy, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4208, https://doi.org/10.5194/egusphere-egu26-4208, 2026.
Instrumental long-term climate records are scarce worldwide, especially in tropical regions such as the Brazilian Amazon. The lack of systematic data prior to the 20th century limits understanding of long-term climate variability and extreme events. This study is situated within the field of Historical climatology. It aims to contribute to knowledge of climate extreme events that occurred during periods of limited climatological data through analysis, focusing on the flooding events of 1859/60 and 1892 in the Amazon River basin. The research aligns 19th-century historical documents, such as newspapers, periodicals, official correspondence, and travel logs, with climate information from dendrochronological studies to reconstruct the magnitude, duration, and impacts of these flood events. Methodologically, it is constructed through an interdisciplinary approach combining environmental history, historical climatology, and hydrology, using written records as climate proxies that provide crucial information on river levels, rainfall seasonality, and flood persistence. Analysis of tree-rings from the Amazonian trees known as “Cedro-Vermelho” (Cedrela Odorata) indicates that the floods of 1859/60 and 1892 were among, if not the, most severe flooding extremes of the 19th century on the Amazon River basin. Historical descriptions of damage to livestock, farming, agriculture, urban infrastructure, and the living conditions of the population, which mainly consisted of “ribeirinhos”, a traditional culture and way of life near the rivers, back this up. The results demonstrate that rescuing and systematizing historical climate information from a region with a traditional lack of instrumental records helps fill a gap in tropical data. Regions such as those analyzed in this study have often been overlooked in historical climate research. The potential of historical records combined with dendrochronological analysis has proven extremely promising. It allows not only cross-validation of information but also the recovery of climate data through a non-conventional method of analyzing climate before the 20th century, helping to build a more comprehensive understanding of past climate in the vast Amazonian territory.
How to cite: Sousa, K., Granato, D., Neto, A., and Nunes, E.: Historical floods of the 19th century in the amazon, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3138, https://doi.org/10.5194/egusphere-egu26-3138, 2026.
Underwater cultural heritage, such as ancient shipwrecks and submerged archaeological sites, faces increasing risks from climate-driven environmental changes. Salinity shifts, temperature anomalies, and biofouling contribute to the degradation of these resources [1]. This study explores deploying 12 IoT-enabled devices with a crowdsourcing strategy to monitor and address these challenges effectively.
Three device variants are available: Type 1 features an acrylic enclosure and is deployable either from boats at depths of 2–3 meters or by divers for short-duration deployments. Type 2 uses an aluminum enclosure and is designed for long-term seabed deployments. Types 1 and 2 both measure temperature, salinity, and pressure. Type 3 is a specialized variant that replaces the pressure sensor with a chlorophyll sensor and is intended for monitoring algal concentrations.
Each device incorporates a data logger built on a microcontroller, connected to sensors via serial interfaces such as RS485 and I2C. The microcontroller interfaces with sensors to record measurements, storing data locally until retrieval. All devices feature a power management system with custom-designed PCBs for efficient energy use.
Data gathered by the devices is stored locally and transferred to a cloud platform via an intuitive mobile app. Communication between the devices and the smartphone uses Bluetooth Low Energy (BLE), while data uploads to the cloud. The application provides immediate and structured access to the data, eliminating the need for additional hardware or infrastructure and enabling seamless data availability without added operational costs.
Community participation plays a central role in this system. Local communities deploy and retrieve boat-based sensors, improving the coverage and frequency of monitoring activities. By pooling data from various contributors, detailed information of environmental conditions near cultural heritage sites is acquired.
The devices are subject to thorough calibration, either through controlled sensing operations or by comparison with ground-truth data acquisitions, to ensure reliable data collection. Conductivity sensors are standardized against established salinity benchmarks, temperature sensors are tested using laboratory-grade reference instruments, pressure sensors are calibrated in controlled pressure chambers, and chlorophyll sensors are validated using fluorescence reference standards.
Field trials at four underwater sites tested the system under diverse conditions, providing a robust environment to assess device performance and crowdsourcing effectiveness. Feedback from divers, local participants, and heritage professionals refined functionality. Adjustments included stronger enclosures, improved BLE connection stability and an enhanced mobile app interface.
This study demonstrates the potential of combining smart sensor technology with community engagement to protect underwater heritage. Leveraging IoT devices and collaboration expands monitoring, reduces costs, and fosters local stewardship, offering a scalable, sustainable solution to mitigate environmental impacts on submerged cultural treasures.
References:
[1] P. Michalis, C. Mazzoli, V. Karathanassi, D. I. Kaya, F. Martins; M. Cocco, A. Guy and A. Amditis, "THETIDA: Enhanced Resilience and Sustainable Preservation of Underwater and Coastal Cultural Heritage," IGARSS 2024 - 2024 IEEE International Geoscience and Remote Sensing Symposium, Athens, Greece, 2024, pp. 2208-2211, doi: 10.1109/IGARSS53475.2024.10642229.
[2] L. Pavlopoulos, P. Michalis, M. Vlachos, A. Georgakopoulos, C. Tsiakos and A. Amditis, "Integrated Sensing Solutions for Monitoring Heritage Risks," IGARSS 2024 - 2024 IEEE International Geoscience and Remote Sensing Symposium, Athens, Greece, 2024, pp. 3352-3355, doi: 10.1109/IGARSS53475.2024.10641101.
Acknowledgement:
This research has been funded by European Union’s Horizon Europe research and innovation programme under THETIDA project (Grant Agreement No. 101095253).
How to cite: Gkatzogias, A., Bitas, D., Georgiou, K., Amditis, A., and Michalis, P.: From Divers to Communities: An IoT-Based Crowdsourcing Sensing Approach to Protect Underwater Heritage Sites, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1934, https://doi.org/10.5194/egusphere-egu26-1934, 2026.
Underwater cultural heritage sites are under increasing pressure from emerging environmental risks: warmer waters and changing seawater chemistry are accelerating corrosion processes in ways that remain difficult to quantify in terms of their impacts on protected archaeological metals. This work proposes an experimental approach that makes these changes measurable and comparable across sites using metallic coupons carefully selected to match materials revealed from a series of wrecks. Coupons were deployed at different depths at four different locations, and retrieved at fixed time intervals. The development of corrosion layers, concretions, and biofouling in the natural environment was investigated. Observations were integrated with results from a second experimental approach. The same set of coupons was exposed to controlled environmental conditions using a custom Micro-Environment Simulator (MES). MES was set to reproduce marine conditions at 4 bar gauge pressure (40 m depth), 20 °C water temperature, and pH 7.7, simulating ocean acidification by the end of this century according to the CMIP6 projections for the Mediterranean under the SSP5-8.5 Warming 4 °C scenario. Results have shown a significant shift in electrochemical equilibria under declining pH, significantly influencing the stability of the corrosion products, and determining a shift in the behaviour of the corrosion layers from protective barrier to pathway for continued metal loss. By linking corrosion behaviour to specific environmental settings, the approach provides indicators of when and where deterioration is likely to accelerate under future scenarios. These outputs support preventive strategies for underwater metallic heritage by identifying high-risk wreck contexts, and guiding actions before irreversible loss occurs.
Acknowledgement:
This research has been funded by European Union’s Horizon Europe research and innovation programme under THETIDA project (Grant Agreement No. 101095253) (Technologies and methods for improved resilience and sustainable preservation of underwater and coastal cultural heritage to cope with climate change, natural hazards and environmental pollution).
How to cite: Cesareo, L. P., Germinario, L., Salvemini, F., MacLeod, I. D., Marchettoni, E., Ambrosi, C., Donnarumma, L., Sorci, A., and Mazzoli, C.: How climate change rewrites metal decay: forecasting ancient shipwreck corrosion under acidified seawater, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20603, https://doi.org/10.5194/egusphere-egu26-20603, 2026.
Our cultural memory is permanently endangered and, often, damaged irretrievably, given that cultural disasters, are quite repetitive, whether in cases of man-made or of natural disasters, armed conflicts and climate change combined with earth’s tectonic activity constituting, potentially, the primary causes.
The southwestern Peloponnese in Greece, precisely the region of Pylia, due to its proximity to the Hellenic trench, is considered to be tectonically as one of the most active areas in Greece, representing a major subduction zone. At the same time, it constitutes also a broad area with a very long history and a wealth of archaeological sites and relics. Focusing on the western coastline of the said region, directly exposed to variations of sea level height, as well as to conditions of rapid erosion due to the aggressive components of seawater, it should be considered as an area of urgent priority to be monitored and protected.
Specifically, Voidokilia bay at the western coast of Messenia Prefecture, to the north of Navarino bay, a highly fragile ecosystem, actually under a NATURA Network protection status, constitutes the related case-study. Nevertheless, Voidokilia bay, is also one of the most attractive landscapes worldwide, thus facing rapid tourism challenges, ending up in increased disaster risks, both for the cultural as well as for the environmental assets. Accordingly, an interdisciplinary methodology within the scientific field of digital humanities has been applied for digitizing archaeological sites, excavated or not, underwater or not, as well as for highlighting their interdependence with the wider Messenia region’s archaeological sites network, further combined with trade routes connecting southwestern Peloponnese and the Aegean islands, via southeastern Peloponnese and Attica, thus fulfilling the notion of applied archaeology.
In this context, applying geoinformatics proved to be the most effective methodology for the related holistic cultural heritage management, in the perspective of an effective strategic planning on the part of the State apparatus, whether for private or public works, taking also into consideration charters, European directives and good practices, already applied worldwide, such as people’s community inclusion, in the direction of a public archaeology model.
The cornerstone of the specific research procedure has been extensive documentation, integration of different data types, such as archaeological, bibliographic, (palaeo)environmental, geospatial, remotely sensed imagery, for building up the sites’ multidimensional profile and revealing spatial relations and settlements’ interdependence, further highlighting the related buffer zones, in the perspective of delineating wider areas of archaeological profile, for anticipating the long-standing threats to archaeological assets such as rapidly increasing tourism, mismanaged development, poor excavation and looting, lack of conservation, climate change posing further significant threats to cultural heritage assets.
Conclusively, further constituting a potential contribution to the archaeological cadastre, already established by the Hellenic Republic, as well as proposing mild tourism development for keeping the balance between urban regeneration and environmental protection, in accordance with the Sustainable Development Goal 11-Sustainable cities and communities, one of the 17 SDGs established by the United Nations General Assembly in 2015, with the official mission to “Make cities inclusive, safe, resilient and sustainable”.
How to cite: Chroni, A. and Karathanassi, V.: The western Peloponnese coastline cultural landscape: cultural heritage management policy tools for making cities inclusive, safe, resilient and sustainable, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2191, https://doi.org/10.5194/egusphere-egu26-2191, 2026.
The preservation of underwater and coastal cultural heritage is challenged by climate change, including sea-level rise, coastal erosion, extreme events and long-term environmental degradation. These threats require not only scientific monitoring and risk assessment, but also active engagement of local communities and stakeholders to foster awareness and citizen centered resilience.
This contribution presents the Augmented Reality (AR) crowdsourcing mobile application, to engage citizens, divers and local communities in exploring heritage sites, understanding climate-related risks and contributing to resilience strategies with collection of ground-truth data. The AR mobile application focuses on providing complex scientific knowledge into intuitive, place-based experiences accessible to non-expert audiences through interactive 3D reconstructions, contextualized information supported by visualizations of environmental and site-specific data over time. The AR mobile app supports enhanced learning and strengthens connections between citizens, heritage sites and scientific evidence, by allowing users to visualize digital content within their physical surroundings.
The application has been deployed across seven underwater and coastal pilot sites: the Equa Shipwreck (La Spezia, Italy), the Albenga A Shipwreck at Gallinara Island (Italy), the Hiorthhamn Arctic mining station (Svalbard, Norway), Lake IJssel (The Netherlands), the B-24 Liberator aircraft wreck (Algarve, Portugal), the Castle of Mykonos (Greece) and the Nissia Shipwreck (Cyprus). Each pilot features a tailored AR campaign reflecting its specific heritage value, ranging from Roman cargo vessels and WWII wrecks to Arctic industrial remains and coastal fortifications. Site-specific content visualises relevant climate hazards such as erosion, sea-level rise, storm impacts and material decay, while enabling users to explore excavation layers, alternative site states and historical reconstructions. The AR experiences are built using optimised 3D scans, reconstruction models, archival imagery, curated scientific content with interactive Points of Interest. Dynamic visualisations illustrate processes such as habitat formation, sediment movement, and structural transformation, supporting a deeper understanding of how environmental change affects heritage over time. All content has been developed in close collaboration with domain experts to ensure scientific accuracy and educational value.
A citizen-engagement study has been conducted to assess usability, user motivation, and the application’s effectiveness in raising awareness of climate risks to cultural heritage. Full validation across all pilot sites is taking place, ensuring that results reflect the cultural, geographic and environmental diversity of the seven pilot sites.
Acknowledgement:
This research has been funded by European Union’s Horizon Europe research and innovation programme under THETIDA project (Grant Agreement No. 101095253) (Technologies and methods for improved resilience and sustainable preservation of underwater and coastal cultural heritage to cope with climate change, natural hazards and environmental pollution).
How to cite: Koukoudis, K., Katika, T., Touramanis, A., Amditis, A., and Michalis, P.: Connecting Citizens, Science, and Vulnerable Heritage: An AR-Based Approach to Climate Resilience , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3862, https://doi.org/10.5194/egusphere-egu26-3862, 2026.
Cultural heritage is exposed to a wide range of risks arising from natural processes, extreme events and human activities, making heritage resilience a challenging and complex issue. Existing risk assessment and management approaches often lack cohesion, difficult to access or insufficiently aligned with the everyday needs of heritage managers and local communities, resulting in gaps in understanding, as well as preparedness and response capacity.
This contribution focuses on addressing these challenges by merging scientific knowledge, field-based experience, and community generated awareness through an integrated digital environment. Within the European project THETIDA, a web-based visualization and decision-support platform has been developed with the main objective of supporting a holistic understanding of cultural heritage resilience. The platform integrates hazard information, environmental monitoring data, socio-economic indicators and spatial representations within a single, accessible interface, enabling users to explore and understand how multiple risks interact and affect heritage assets and their surrounding environments.
The platform delivers three main categories of services: (i) Remote Sensing–Based Services, including inundation and flood prediction, coastal erosion monitoring, material degradation mapping, land-use change detection, and geo-hazard assessment; (ii) In-Situ Sensing Services, supporting on-site monitoring and material characterization; and (iii) a Decision Support System providing seismic hazard analysis, multi-risk assessment, and socio-economic impact evaluation. Interactive geospatial functionalities allow users to explore datasets through structured spatial representations, such as hexagonal grid systems and visualize multiple data layers simultaneously. The system operates through standard web browsers without the need for specialized GIS software, ensuring accessibility for diverse user groups, including heritage professionals, decision-makers and local communities. Multiple data formats, such as GeoJSON, TIFF, PDF, 3D models and imagery, are processed and visualized in near real time within the platform.
Τhe results demonstrate that the integration of digital tools is not only considered as a technological advancement but also as a key enabler for collaboration, participation and sustainable heritage management. Interactive and cooperative digital environments can significantly enhance the resilience of cultural heritage sites to climate and disaster-related risks, supporting informed, inclusive and actionable management strategies.
Acknowledgement:
This research has been funded by European Union’s Horizon Europe research and innovation program under THETIDA project (Grant Agreement No. 101095253) (Technologies and methods for improved resilience and sustainable preservation of underwater and coastal cultural heritage to cope with climate change, natural hazards and environmental pollution).
How to cite: Georgiou, K., Routsis, K., Michalis, P., and Amditis, A.: Digital Integration of Environmental, Socio-Economic and Hazard Data for Heritage Resilience, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9183, https://doi.org/10.5194/egusphere-egu26-9183, 2026.
Temperature essential for all the life form, but when the same temperature crosses its threshold limit it can become a threat for the same. In the recent decades the world has experienced a shift in temperature range both minima and maxima, as both are shifting towards the higher tail. And this is detrimental for health and air quality. Also very few studies talk about how rising temperature can impact the air quality and vice versa. Therefore, in the present work we have studied the long term heatwave pattern over Delhi, India using the ground based and satellite data observations. Delhi is known for its hot summers, landlocked geography and dense population. During May 2022 , city experienced long heat wave event where daily maximum temperature observed higher than 40 OC for consecutively around 10 days which not only causes heat stress but also the pollution stress over the city as the concentration of Particulate matter (PM10 and PM2.5) observed significantly higher than the non-heatwave period of the month. Air Quality Index (AQI) was moved from moderate to very poor during the heatwave period compared to non-heatwave where AQI showed satisfactory to poor condition. Further we observed that the Temp and Demand data increases monotonically during this period from 30 °C with demand ≈4500–5200 MW to about 38 °C with demand ≈6800–7070 MW, indicating a strong positive linear response. The regression analysis showed with 1°C increase in air temperature can increase the city demand by 97MW with r=0.61. We have further calculated night vs day slope, indicate that when night stays hot (>35°C) people might be keep cooling system running more intensely or for longer hours. And each degree increase in nighttime temperature put much larger load on demand compared to same warming during the day.
How to cite: Masiwal, R., Ganguly, D., and Kunchala, R.: Heatwave and Air pollution, a synergetic effect or not: A case Study, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21797, https://doi.org/10.5194/egusphere-egu26-21797, 2026.
This study develops a novel multi-criteria framework for the identification of intra-urban heat islands by integrating indicators related to three-dimensional urban morphology (e.g., height-to-width ratio and sky view factor), land cover characteristics, satellite-derived land surface temperature, and thermal comfort conditions. The proposed framework practically enables the delineation of urban areas with distinct thermal and morphological profiles, thereby providing a robust basis for targeted, site-specific intervention strategies.
Subsequently, a range of bioclimatic heat mitigation measures is assessed for selected hotspots, including nature-based solutions such as increased tree planting and green roofs, as well as the application of high-albedo (cool) materials. The effectiveness of these measures is evaluated using advanced urban climate simulation models (ENVI-met and UT&C), allowing for a comparative assessment of their performance under varying spatial configurations and microclimatic conditions.
Overall, the study provides evidence-based guidance for urban heat mitigation and supports climate-resilient urban planning in Mediterranean cities, with Athens serving as a representative case study.
How to cite: Oikonomou, M., Agathangelidis, I., and Cartalis, C.: Development of a Multi-Criteria Framework for Identifying Intra-Urban Heat Islands in Support of Urban Heat Mitigation in Athens, Greece, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14400, https://doi.org/10.5194/egusphere-egu26-14400, 2026.
Limestone cultural heritage has increasingly been threatened by the complex interplay of climatic stressors, air pollution, and biological colonization. In this STECCI study, a bio-geochemical dose-response framework was introduced to quantify and interpret the decay of stećci-medieval tombstones constructed from locally sourced limestone, across fifteen culturally significant sites in Southeastern Europe. While existing dose-response functions (DRFs) have traditionally been applied to climatic, chemical and physical weathering, biological link has often been in the Blind Spot, despite mounting evidence that lichens, mosses, and microbial taxa contribute actively to stone decay.
Two widely used DRF models Lipfert (1989) and Kucera et al. (2007) were applied to multi-decadal environmental data (1992-2023), accounting for variations in precipitation, temperature, and pollutant load (SO₂, NOₓ, PM₁₀). Bioassement surveys were conducted to record biological colonization using a modified Braun-Blanquet scale and photographic quadrat sampling. At the same toime, spatial overlays of DRF results and biological data were produced to identify zones of specific vulnerability, where climatic exposure and biodeteriogen presence were observed to overlap. As expected, the Lipfert model responded more strongly to high-precipitation karstic settings, while the Kucera model captured the cumulative effect of pollutants and humidity in urban sites. However, both models were shown to underestimate decay in areas with extensive lichen or moss coverage, highlighting the need for biotic factors to be integrated into predictive modeling. To address this, a multi-stressor approach was developed, coupling DRF-predicted surface recession with biological indicators and introdicing b coficient within the both mathematical models, as Lithobiontic organisms, such as Lobothallia cheresina, Xanthoria elegans, and Grimmia pulvinata, were found to contribute to micro-fracturing, mineral leaching, and, most importantly, moisture retention, often acting synergistically with atmospheric deposition. Based on these insights, a STECCI Preservation Measures Assessment tool was proposed to classify heritage sites according to modeled decay, biocolonization intensity, and conservation urgency.
This integrative methodology was conducted to sharp the diagnostic capacity of DRFs and enabled the generation of science-based insights, integrating risk assessment models for heritage exposed to climatic, natural, and anthropogenic hazards. In light of projected climate shifts and persistent anthropogenic emissions, it is recommended that heritage conservation efforts adopt bio-geo diagnostics to transition from reactive toward preventive conservation strategies. The approach presented here is transferable to other limestone heritage materials and contributes to the growing discourse on climate-resilient cultural heritage preservation.
Acknowledgement: The STECCI project has received funding from the European Union’s Horizon Europe research and innovation programme under Grant Agreement No. 101094822 (STECCI), managed by the European Research Executive Agency (REA).
How to cite: Radulović, S., Anačkov, G., Radak, B., Ilić, M., Radulović, B., Novković, M., Djug, S., Smailagić Vesnić, L., Ibragić, S., and Dresković, N.: Breaking Disciplinary Boundaries: Bringing the Biological Role out of the Blind Spot in DRF-Based Assessments of Limestone Weathering under a Changing Climate, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14335, https://doi.org/10.5194/egusphere-egu26-14335, 2026.
The contribution of EM4C to the TRIQUETRA project addressed a central challenge in contemporary cultural heritage protection: transforming complex scientific risk assessment knowledge into practical, operational tools that support informed decision-making by professionals and heritage authorities. From the outset, EM4C adopted an application-oriented approach, extending beyond academic research to the development of structured methodologies and digital decision-support tools aligned with real-world conservation needs.
EM4C’s involvement spanned the full project lifecycle, from methodological design and knowledge structuring (WP3) to validation and evaluation (WP6), assessment of exploitation potential and future development pathways (WP7), and contribution to reporting and documentation activities (WP1). This integrated engagement ensured continuity between research, implementation, evaluation, and long-term usability of project outcomes.
Within WP3, and particularly Task 3.6, EM4C acted as task leader for the development of tools, methods, and technologies aimed at mitigating risks to cultural heritage sites. The work recognized that heritage vulnerability results from the interaction of multiple factors, including construction materials, environmental conditions, historical interventions, patterns of use, and diverse natural hazards exacerbated by climate change. Rather than addressing these factors in isolation, EM4C developed a structured framework reflecting real-world site behavior, where risks emerge through combined and cumulative effects over time.
A major challenge identified was the extreme complexity of potential risk scenarios. Initial theoretical analysis showed that more than 1.8 million combinations could arise when accounting for all variables, rendering manual assessment impractical. EM4C addressed this through a rational reduction process, grouping construction materials into four realistic tri-material combinations commonly found in heritage sites. This filtering reduced the scenario space to 15,120 valid and prioritized cases, maintaining representativeness while ensuring usability.
These scenarios were implemented digitally through two decision-support tools: the M REPORT ENGINE for monument-scale assessments and the LS REPORT ENGINE for landscape-scale risk management. Both tools generate structured technical outputs based on user-selected parameters such as materials, hazards, and risk intensity. Crucially, the proposed conservation and protection measures are grounded in an extensive manual synthesis of scientific literature, technical guidelines, and recognized good practices, ensuring technical accuracy, consistent terminology, and non-commercial neutrality.
The developed tools were evaluated within WP6 through presentations and hands-on assessments involving conservators, engineers, and cultural heritage authorities, including representatives of the Hellenic Ministry of Culture. Feedback collected through questionnaires and qualitative observations confirmed the tools’ clarity, relevance, and capacity to support structured decision-making, while also identifying directions for future refinement.
Within WP7, EM4C assessed the exploitation potential of the model and tools, demonstrating their adaptability to diverse institutional contexts and their suitability as flexible decision-support systems. The work highlighted their potential evolution into more specialized, data-integrated applications.
Overall, EM4C’s contribution effectively bridged theory and practice, delivering scientifically robust yet operationally meaningful tools that enhance the long-term impact and applicability of the TRIQUETRA approach to cultural heritage risk management.
How to cite: Spyrakos, V.: ABSTRACT - Overall Contribution of EM4C to the TRIQUETRA Project , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5292, https://doi.org/10.5194/egusphere-egu26-5292, 2026.
The Norian-Rhaetian boundary (NRB) marks a critical interval of Late Triassic global environmental instability, ecological crisis, and climatic transition, which preceded the sustained biodiversity decline culminating in the end-Triassic mass extinction. Despite its significance, the drivers of carbon cycle and biotic disturbances across the NRB remain unresolved. In most cases, these major mass extinctions in geological history are interpreted as chain reactions triggered by volcanic activity. Interestingly, the NRB and Rhaetian intervals lack compelling evidence for synchronous, precisely dated, large-scale volcanism with demonstrable global effects. In this context, the Central Atlantic Magmatic Province (CAMP) erupted later at ca. 201 Ma, while other impact-related triggers and/or proposed large igneous provinces (LIP), such as the Angayucham LIP in Alaska (214 ± 7 Ma), remained weakly constrained in magmatic timing, magnitude, and environmental significance. In the absence of significant volcanism, the mechanisms underlying carbon cycle perturbations and ecological crises become even more enigmatic.
Here, we present a high-resolution carbonate carbon isotope (δ13Ccarb) profile spanning the Late Triassic to Early Jurassic from South China. Through independent U-Pb dating and cyclostratigraphic analysis, a high-precision astronomical timescale was established. Carbon isotope variations are strongly controlled by orbital cycles, and the record reveals two large-magnitude negative carbon isotope excursions (CIEs) at ca. 205 Ma and 201 Ma, corresponding to the NRB and Triassic-Jurassic Boundary (TJB), respectively. Our study posits that astronomically driven climate change persistently influenced the NRB and subsequent Rhaetian intervals, triggering a series of chain reactions involving climate, vegetation, carbon burial, greenhouse gas emissions, and other factors. Ultimately, it acted as an amplifier in the NRB event, leading to carbon cycle perturbations and ecological crises during this period, thus potentially preconditioning the Earth system for the subsequent end-Triassic mass extinction. This study further highlights the significance of low-latitude coastal areas as dynamic amplifiers of carbon cycle instability and underscores the vulnerability of modern carbon reservoirs under ongoing climate change.
How to cite: Lu, T. and Fu, X.: Astronomically Driven Climate Change as an Amplifier of Carbon Cycle Instability and Ecological Crisis at the Norian-Rhaetian Boundary, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8903, https://doi.org/10.5194/egusphere-egu26-8903, 2026.
A realistic representation of sea surface temperature (SST) variability in climate models is essential for seasonal-to-interannual forecasting and for understanding large-scale climate oscillations. This study evaluates the impact of three initialization strategies in the NorCPM coupled climate model on the structure and temporal evolution of the leading modes of global SST variability over the 1980–2010 period. The analyzed strategies include a free-running simulation (FREE), ocean data assimilation using an ensemble Kalman filter (ODA), and atmospheric nudging of wind and temperature anomalies (NUDA_UVT). Model results are evaluated against the HadISST observational dataset.
Empirical Orthogonal Function (EOF) analysis is applied to monthly SST anomalies computed over the full globe and using all calendar months, without regional restriction or seasonal stratification. This framework enables a consistent comparison of the dominant large-scale SST variability modes across all datasets. The results indicate that ocean data assimilation (ODA) best reproduces the leading ENSO-related mode, achieving a spatial correlation of 0.98 and the lowest root mean square error in its principal component (RMSE = 1.70). For the second mode, associated with lower-frequency variability, atmospheric nudging (NUDA_UVT) shows improved spatial agreement (correlation = 0.90) compared to ODA. The free-running simulation captures the main spatial structures but displays systematically larger temporal errors.
These findings demonstrate that ocean data assimilation is the most effective strategy for representing ENSO-like variability in NorCPM, while atmospheric nudging provides added value for lower-frequency modes. As a perspective, this work will be extended to investigate the impact of initialization strategies on atmospheric fields, as well as to explore SST variability at specific seasonal and regional scales.
How to cite: Moutachaouiq, K., Bari, D., Omrani, N.-E., and Nafiri, S.: Impact of Different Initialization Strategies on the Representation of Dominant SST Variability Modes in the NorCPM Coupled Climate Model, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17596, https://doi.org/10.5194/egusphere-egu26-17596, 2026.
Tropical convectionanomaly could serve as a crucial driver of global atmospheric teleconnections and weather extremes around the world. However, quantifying the dominances of convection anomalies with regional discrepancies, relevant for the variations of global atmospheric circulations, remains challenging. By using a network analysis of observation-based rainfall and ERA5 reanalysis datasets, our study reveals that El Niño-like convection is the most primary rainfall pattern driving the global atmospheric circulation variations. High local concurrences of above-normal rainfall events over equatorial central-eastern Pacific amplify their impacts, even though the most intense rainfall anomalies are observed near the Maritime Continent. Furthermore, we find that the impacts of El Niño- like convection will be tripled by the end of this century, as projected consistently by 23 climate models. Such “rich nodes get richer” phenomenon is probably attributable to the dipolar rainfall changes over theequatorial western-central Pacific. This study highlights the dominant role of El Niño- like convection on the global climate variations, especially under the future changing climate.
How to cite: Lin, S., Cai, F., Gerten, D., Yang, S., Jiang, X., Su, Z., and Kurths, J.: Intensified dominance of El Niño-like convection relevant for global atmospheric circulation variations, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4441, https://doi.org/10.5194/egusphere-egu26-4441, 2026.
Tide-gauge observations are among the most reliable sources for assessing sea-level variability and its seasonal and temporal changes in coastal regions. This study analyzes sea-level records obtained from tide gauges along the Angolan coast for the period 2015–2020, with the objective of characterizing the seasonal and interannual variability of tides. The methodology included quality control and pre-processing of hourly and monthly sea-level data, removal of non-tidal signals, harmonic tidal analysis, and the assessment of seasonal variability and its statistical significance. Despite limitations related to data gaps, limited temporal resolution, and the lack of complementary oceanographic data, the results reveal pronounced seasonal and interannual variability in sea level. This variability reflects the combined influence of tidal dynamics, regional ocean circulation, wind forcing, and climate-related processes. The analysis highlights the importance of continuous and homogeneous tide-gauge records along the Angolan coast for improving the detection and interpretation of sea-level variability. The findings contribute to coastal monitoring efforts and provide relevant information for coastal management, risk assessment, and the development of adaptation strategies in the context of sea-level change.
Keywords: Sea level variability, Tide-gauge observations, Seasonal and interannual variability, Angolan coast.
How to cite: Guilherme, F., Neves, M., and Lamas, L.: Seasonal and Interannual Variability of Tide-Gauge Records along the Angolan Coast for the period 2015 – 2020 , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4120, https://doi.org/10.5194/egusphere-egu26-4120, 2026.
The Paraná basin is composed of stratigraphic units that record distinct paleoenvironmental settings, organized into six supersequences. The Gondwana I Supersequence (Permian) records a transgressive-regressive cycle associated with tectonic and climatic changes, in which periglacial successions (Itararé Group), coastal and marine (Guatá Group), and continental deposits (Passa Dois Group) are preserved. These sedimentary units crop out along the eastern margin of the Paraná Basin in a complex structural configuration that reveals significant tectonic displacements attributed to normal faults, resulting in the lateral juxtaposition of stratigraphically distinct units. Due to this arrangement, volcanogenic deposits play a fundamental role as stratigraphic markers, as they allow the establishment of precise geochronological correlations. This study presents geochronological data obtained from a volcanogenic deposit at Morro dos Conventos outcrop, and compares it with a compilation of the ages of volcaniclastic sediments interbedded with sedimentary deposits from the Rio Bonito Formation, aiming to constrain the evolution of depositional systems that enabled the preservation of such volcanogenic deposits within this interval. The detailed stratigraphic section of the outcrop was conducted and samples were collected for geochronological analysis. U-Pb zircon ages were determined by LA-MC-ICP-MS from a volcanogenic layer. The results reveal a unimodal zircon population with a concordia age of 286 ± 1.4 Ma (N = 9; MSWD = 1.2), allowing correlation of the deposit with the Artinskian Stage. Sedimentological and stratigraphic analysis of the section indicates a paleoenvironment of storm wave-dominated shelf, with interbedded subsystems recording high-frequency cycles associated with changes in sea level or sedimentation rates within the second-order Permian transgressive sequence. Sedimentological and geochronological data suggest that the studied succession correlates with the upper portion of the Rio Bonito Formation, in a context of progressive drowning by the Palermo Sea. At the top of the section, a progradation of subsystems is observed, characterized by the arrangement of subaerial sequences under humid backshore conditions. A similar configuration has been documented in other areas of the basin during the Cisuralian, where pelitic successions associated with coal deposits preserve centimeter-thick intercalated volcanic ash layers. The preservation of these features is attributed to paleoenvironmental conditions of subsystems developed along the margins of subaqueous bodies, dominated by low-energy settings with limited reworking, favoring the deposition of fine-grained sediments. In the studied outcrop, the preservation of the volcanogenic deposit is interpreted as a result of deposition within fine-grained sediments characterized by redoximorphic structures, indicative of fluctuating conditions between dry and wet periods typical of subaerial environments influenced by aqueous systems. A similar preservation context is observed in volcanogenic deposits recorded both in CPRM wells (Brazilian Geological Survey) and in nearby outcrops of this stratigraphic interval. The coexistence of low-energy depositional systems and episodes of high-magnitude explosive volcanism along the western margin of Gondwana enabled the preservation of ash-fall deposits in the Paraná Basin stratigraphic record, commonly associated with the Choiyoi Magmatism during the proposed Rio Bonito Formation sedimentation interval.
How to cite: Ribeiro Franqueira, A. V., Bettarel Bállico, M., Moreira Florisbal, L., Oliveira Manna, M., and Marlon dos Santos Scherer, C.: Controls on Ash-Fall Deposit Preservation in Low-Energy Depositional Systems of the Rio Bonito Formation, Paraná Basin, Brazil, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14428, https://doi.org/10.5194/egusphere-egu26-14428, 2026.
One approach to reduce the uncertaintites in the black carbon (BC) emissions estimated using the bottom-up inventories is by integrating the atmospheric models with observational data. In this study, we estimate aerosol emissions over Europe (15◦W–35◦E, 33–73 ◦N) by assimilating surface observations of BC from EBAS network using Local Ensemble Transform Kalman Filter (LETKF) in the LOTOS-EUROS chemical transport model. Sensitivity experiments indicate that an ensemble size of 24 and a localization distance of 300 km provide optimal performance. Furthermore, we assess the influence of CAMS BC boundary conditions on the emission estimates and find that these boundary conditions tend to overestimate BC concentrations near the domain boundaries.
Our results show that the bottom-up approach generally overestimates BC emissions across Europe. Quantitatively, the posterior emissions are found to be 21% and 30% lower than the prior emissions for the years 2011 and 2021, respectively. A reduction in both emissions and associated uncertainties is observed over central Europe, where the observations are dense. Seasonal analysis reveals that emission decreases are most pronounced over the central domain during autumn and winter. Finally, the validation of optimized BC concentrations with independent observations showed a decrease in bias and RMSE, however the correlation remains poor compared to the background concentrations.
How to cite: George, B., Thomasson, A., Roldin, P., Segers, A., and Schutgens, N.: Optimizing Aerosol Emissions over Europe using Surface Black Carbon Measurements, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19525, https://doi.org/10.5194/egusphere-egu26-19525, 2026.
The aim of this study is to explore links between large-scale atmospheric circulation and meteorological and hydrological drought events in the Danube basin.
Based on previous studies on the relationship between large-scale atmospheric circulation and the occurrence of extreme events in the Danube basin, especially in the middle and lower Danube basin, two climate indices were considered. The first index characterizes the Greenland-Balkan Oscillation (GBOI) and the second is the well-known index associated with the North Atlantic Oscillation (NAOI). For meteorological and hydrological drought, the Palmer Drought Severity Index (PDSI), with applications especially in the agricultural field, and, respectively, the Palmer Hydrological Drought Index (PHDI), especially useful for estimating drought affecting water resources on longer timescales, were taken into account.
To find the type of connection (linear/non-linear) between large-scale climate indices (GBOI, NAOI) and those at the regional scale (PDSI, PHDI), elements from information theory, such as mutual information, were applied. To get time-frequency details, bivariate and multivariate wavelet transforms were used.
The analyses were performed separately for each season. The most statistically significant results were obtained both for the link between GBOI and PDSI, in the winter season, and for that between GBOI and the two analysed Palmer indices, in the spring season.
Regarding the influence of NAOI, it is much less than that of GBOI, but it can be considered relatively significant in winter on PDSI and in spring on PHDI.
From the wavelet coherence analyses it was observed that the significant coherences between the large-scale atmospheric indices and the analysed Palmer drought indices are located in frequency bands, corresponding to ~11–year, 22-year and 33-year period bands, that can be associated with the Schwabe, Hale and even Bruckner solar activity cycles.
In exploring regional-scale droughts, for the future studies, it appeared evident the importance of taking into account of the simultaneous or delayed influence of solar activity on terrestrial climate variables.
How to cite: Mares, C., Mares, I., Dobrica, V., and Demetrescu, C.: On the links between large-scale atmospheric circulation and extreme events in the Danube basin, identified by Palmer drought indices, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10629, https://doi.org/10.5194/egusphere-egu26-10629, 2026.
Urban areas are increasingly exposed to flood hazards due to climate change, densification and growing urbanization. Remote sensing datasets can be used to monitor the floods and warn the population. Much more, simulations of hazards, using high resolution geospatial datasets combined with meteorological data can be derived. In this case, solutions prior to the events can be implemented, so increasing the resilience of cities to natural hazards.
This study presents a high-resolution 3D urban model of Brașov, Romania, developed from an airborne photogrammetric datasets acquired in 2025, and its application in urban flood risk assessment. The 3D building models were obtained using footprints from the national topographic database and the height derived from the computed normalized Digital Surface Model (nDSM). For the flood modelling the hydrological network and land cover data were used.
To assess flood risk, time series precipitation dataset was analyzed and used in the modelling framework. The combined analysis under different scenarios, enabled the identification of flood areas and the estimation of the number of exposed buildings. The results highlight the importance of high-resolution 3D urban data for understanding flood dynamics in complex urban settings and support decision-making processes related to urban planning, risk mitigation, and climate resilience. The output also represents a starting point for a Digital Twin for Brașov.
How to cite: Pârvu, I., Cuibac, I., Pârvu, A., Pârvulescu, N., Corneanu, I., Cheval, S., Crăciunescu, V., Dumitrescu, A., Amihaesei, V., Gabrian, Ș., Dinicila, Ș., and Tudose, N.: Urban Flood Risk Assessment Using High-Resolution 3D Building Models and Multi-Temporal Meteorological Data, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11292, https://doi.org/10.5194/egusphere-egu26-11292, 2026.
Cloudbursts, defined as sudden, intense rainfall episodes, are increasingly frequent extreme weather events in the Indo-Himalayan region, causing widespread devastation to human life and property; yet understanding their causal mechanisms and improving predictability remains constrained by incomplete knowledge of atmospheric and land-based precursors. Particularly, the role of soil moisture as a vital land-surface component has been underexplored in the context of cloudburst formation. This study hypothesizes that increased soil moisture from agricultural irrigation amplifies atmospheric moisture fluxes via land-atmosphere coupling and contributes to enhanced cloudburst risk. The objective here is to attribute moisture source locations, identify critical pre-event land-atmospheric indicators, and assess soil–atmosphere coupling through the analysis of IMD-specified cloudburst events from 1991 to 2020 using the Indian Land Data Assimilation System (ILDAS) dataset. We employ NOAA's Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectory model and create Integrated Vapor Transport (IVT) maps, composited with winds, surface pressure, and sea level pressure, to trace moisture source locations. Pre-event anomaly detection and change-point analysis are performed using the Pruned Exact Linear Time (PELT) algorithm on soil moisture, precipitation, evaporation, and runoff variables across nine spatially proximate grid cells per event. Additionally, extreme percentile threshold exceedances and non-parametric persistence metrics quantify the early-warning potential. Decadal NDVI trends contextualize Land Use/Land Cover (LULC) influences. Results reveal moisture source hotspots in regions undergoing land-use transitions, with steep pressure gradients establishing strong circulation patterns that contribute moisture to multiple cloudburst events. Significant temporal anomalies occur across all four variables, with threshold exceedances and change-point detections ranging from 2 to 10 occurrences per event and anomaly persistence spanning 2 to 8 days for soil moisture. Early warning lead times of 15 to 120 days are identified for soil moisture, precipitation, evaporation, and runoff anomalies preceding the cloudburst events. These findings suggest that further quantifying the causal links among these variables can better help understand soil–atmosphere coupling and substantially improve early warning systems for detecting extreme rainfall events.
How to cite: Kaushal, A., Saharia, M., and Rajagopalan, B.: Land-Atmosphere Drivers of Cloudburst Events, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19097, https://doi.org/10.5194/egusphere-egu26-19097, 2026.
The Central Ganga Plain (CGP), a key sector of the Indo-Gangetic foreland basin, contains thick, continuous Quaternary alluvial sequences. Its rapidly subsiding basins preserve a high-resolution terrestrial archive, ideal for reconstructing Indian Summer Monsoon (ISM). This study examines sedimentary profiles from distinct river systems in the Central Ganga Plain (CGP) using a multi-proxy framework. A Late Quaternary trench from the Gomti river (26°52′ N, 80°56′ E, Lucknow) and a Holocene section from the Betwa river (25°28′ N, 79°5′ E, Hamirpur). Sediment sample from Lucknow profile were analysed for CHNS, AMS ¹⁴C dating, mineral magnetism, and bulk geochemistry (major, trace, and REE), while those from Hamirpur were analysed using OSL and AMS ¹⁴C dating, alongside CHNS. The established chronology or Lucknow trench, record from ~24 to 3 kyr BP. The CHNS data shows a significant shift at ~20 kyr, marked by high TOC (3.97%) and C/S ratio (~ 300) indicating enhanced organic productivity and freshwater conditions. Concurrent mineral magnetic signatures (χlf, SIRM and ꭓARM) suggest strong detrital input linked to weaker monsoon. This evolving climatic condition is further investigated through bulk geochemistry, (major, trace and REE), which provide critical insights into sediment provenance, weathering regimes, and paleo-hydrological conditions. The chronology for the Hamirpur trench covers from ~800-12000 years BP and the CHNS data provide distinct environmental phases, marked by a sharp peak in TC (3.31%), TOC (1.56%) and C/N ratio (~439), indicating a enhanced terrestrial organic matter preservation in a low-energy, waterlogged setting around ~3000 kyr BP. This integrated high-resolution multiproxy record from the two distinct river systems provides new insights into monsoon variability and sedimentary responses in the Central Ganga Plain during the late Quaternary.
How to cite: Jayakumar, J., ms, A., phartiyal, B., sharma, A., Kumar, P., D. Chauhan, G., and kannan, P.: Multi-Proxy Reconstruction of Late Quaternary Monsoon Variability and Fluvial Response in the Central Ganga Plain, India: Insights from magnetic, CHNS and geochemistry records., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1046, https://doi.org/10.5194/egusphere-egu26-1046, 2026.
Underwater cultural heritage (UCH) is threatened by climatic risks, natural hazards, pollution and human induced activities, which increases the need for integrated monitoring approaches that combine advanced technologies with reliable in situ observations. This study presents the experience gained during underwater operations carried out in THETIDA project. This involved the deployment of coordinated teams of specialized and recreational divers across four Mediterranean pilot sites for data collection and documentation in support of integrated monitoring and protection of UCH sites. Diving teams were systematically deployed to collect various datasets (e.g. high-resolution photographic and video data), perform archaeological measurements, mapping using established underwater archaeology techniques and provide ground truth and spatial referencing data using a series of underwater technologies (e.g. wearable sensors, hyperspectral cameras, autonomous under water vehicles, among others).
At the 18th-century Nissia shipwreck (Cyprus), diving operations were carried out in parallel with a site excavation, hyperspectral imaging of wooden structures, material and biofouling sampling and the deployment of wearable, seabed and boat operated environmental sensing systems. Comparable methodologies were applied at deeper sites, including the WWII Equa shipwreck and the Roman Albenga II shipwreck of Gallinara Island (Italy), as well as the WWII B-24 Liberator aircraft (Portugal). Across these sites, divers performed detailed photogrammetric surveys and 3D reconstructions, in operations under constrained visibility and challenging conditions, putting into practice the validation of the performance and durability of prototype underwater sensing devices. Diver observations obtained at sites were also considered essential for the identification of site-specific risks, such as sediment mobility, biological colonization and physical disturbances. In addition to scientific data acquisition, the underwater operations supported participatory monitoring through citizen-science activities (operation of boat sensing devices), aiming to contribute to long-term site and data continuity.
The obtained results demonstrate that diving underwater operations are considered to be a key complementary component for integrated UCH monitoring, merging knowledge from specialist expertise with sensor-based systems in an effort to enhance informed conservation and protection strategies. Data gathered is also essential for the development of hazard and risk models that allow the prediction and aid the management of these UCH. The experience gained indicates that diving data collection is essential for integrating archaeological documentation, environmental sensing, and survey data under real field conditions. Underwater diver-led operations can serve as both primary data collectors and ground-truth contributors effectively bridging together human expertise with advanced monitoring technologies for the protection of underwater cultural heritage.
Acknowledgement:
This research has been funded by European Union’s Horizon Europe research and innovation programme under THETIDA project (Grant Agreement No. 101095253) (Technologies and methods for improved resilience and sustainable preservation of underwater and coastal cultural heritage to cope with climate change, natural hazards and environmental pollution).
How to cite: Michalis, P., Demesticha, S., Giatsiatsou, P., Demetriou, A., Ruberti, F., Gabotto, G., Martins, F., Mazzoli, C., and Amditis, A.: Underwater Operations for Data Collection in Integrated Cultural Heritage Monitoring and Protection, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1982, https://doi.org/10.5194/egusphere-egu26-1982, 2026.
The Pliocene (5.33-2.58 Ma) was comparatively warmer (+ 1.8-3.6 0C) than today and was characterized by elevated CO2 concentrations (400 ppmv). Thus, studying sedimentary sequences dated to this interval can serve as excellent analogues for comparing present conditions and provide tools for better modeling future trends. Yet, while most studies rely on marine archives, continental data dating back to this interval are scarce, particularly from boundary regions such as the Levantine Corridor. Sediments from the Erk-el-Ahmar Fm. (lacustrine, 3.9 Ma, Jordan Valley, Israel) and Bnot Lot member of the Sedom Fm. (lagoonal/lacustrine, 3.2-4.0 Ma, Dead Sea, Israel) highlight as one of the few well-exposed continental archives in the region that date back to that time.
In the present contribution, we explore these two sedimentary archives and integrate in a multi-proxy fashion the physical, chemical, and biological properties of both outcrop and core sections (with the latter only retrieved from the Erk-el-Ahmar sequence). This study aims to reconstruct the paleoenvironmental setting and changing hydroclimatic conditions in the Levantine Corridor during these time intervals. By amalgamating the datasets, we show that while the region is characterized by increased warmth and augmentation in precipitation patterns, occasional cooling phases coupled with drought punctuate the Pliocene climatic history in the Levantine region.
By synthesizing these diverse datasets into a consistent narrative, the project illuminates how precipitation, evaporation, and ecosystem processes interact under high-CO2 and high-temperature conditions. The outcomes provide the first robust benchmark of Pliocene hydroclimate evolution in the Levantine Corridor, offering critical insight into thresholds of lake resilience, feedback mechanisms, and the persistence of aquatic systems under sustained global warmth.
How to cite: Waldmann, N., Yunfa, M., Olaopa, O., Danish, M., Niu, G., Greenlee, J., Parth, S., Mazzini, I., Castañeda, I., and Taha, N.: Sharp turnovers in Pliocene hydroclimate variability in the Levantine Corridor, East Mediterranean, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17979, https://doi.org/10.5194/egusphere-egu26-17979, 2026.
