The extreme weather events are characterised by short bursts of intense exchange of mass, energy and momentum in the Earth system, originating due to thermodynamic and dynamic reasons. These events impact the functioning of ecosystems, visible in their immediate carbon uptake, water loss, and associated energy exchanges with the atmosphere. However, if the ecosystems are frequently exposed to such episodes, their physiological responses may also adapt to maximise their carbon uptake or minimise their water loss. In future, the extreme events are projected to be more severe and frequent and thus would impact biosphere-atmosphere exchanges greatly.

Such effects can be identified from the long-term time series of ecosystem-atmosphere flux measurements using a wide range of in situ and remote sensing (RS) observations. The eddy covariance (EC) technique provides the most accurate measurements of ecosystem-atmosphere exchanges, and they have now existed for several decades at multiple locations on the globe. RS allows for synoptic-scale monitoring of the biosphere-atmosphere fluxes and detection of extreme events in real time. For instance, precipitation data based on GPM can be employed to detect extreme precipitation and related extremes such as dry/wet spells, tropical cyclones, and others. Likewise, satellite-derived Land Surface Temperature (LST) data from MODIS or ECOSTRESS can be utilised to capture thermal extremes like heat/cold waves. The EC data helps in validating RS data, and when employed in integration with RS data, it would yield robust results. An array of techniques, such as different suitable time series, power spectrum and causal inference approach, can establish detailed insights.

In this session, we invite submissions addressing these different aspects of the influence of extreme events on the ecosystem-atmosphere exchanges of gases and energy across scales. We encourage using the long-term measurements to identify such episodes of ‘disturbance’ and examine their impacts on the biosphere-atmosphere exchanges.