EGU 2022 session anouncement: Stratospheric aerosol during the post Pinatubo era: processes, interactions, and impact

We are happy to announce two SPARC relevant session at the next EGU 2022, 3-8 April, Vienna.

Deadline for submitting related abstracts to these sessions is 05 January 2022!

First session:
AS3.6: The role of the middle atmosphere in a changing climate:  circulation, composition changes and radiative feedbacks

Convener: Mohamadou Diallo
Co-conveners: Gabriel Chiodo, William Ball, Birgit Hassler, James Keeble

Abstract: Anthropogenic emissions of greenhouse gases and ozone depleting substances have caused substantial changes in the chemical composition of the middle atmosphere that, in turn, can influence tropospheric processes. Increasing greenhouse gas levels are expected to modify the stratospheric amount of key radiatively active gases, such as water vapor, ozone and stratospheric aerosols through changes in the stratospheric Brewer-Dobson circulation (BDC). Changes in stratospheric ozone can in turn affect the biosphere (via e.g. changes in UV exposure) and feed back on surface climate via their influence on Earth’s radiative budget. In addition, long-term changes in the ozone layer (e.g. ozone hole and recovery) are known to influence the tropospheric circulation and may be further coupled to a variety of Earth system feedbacks, which are to date poorly understood.

We welcome abstracts which explore composition changes and resulting radiative impacts and feedbacks on the tropospheric and stratospheric circulation as well as on surface weather and climate. Abstracts may address these issues on time-scales encompassing inter-annual to centennial timescales as well as impacts ranging from the tropics to poles. In particular, new studies on the influence of stratospheric ozone and composition on weather and climate are of interest. Research might also concern long-term ozone trends (depletion and recovery), as well as water vapor changes and volcanic aerosol impact in the stratosphere. We welcome contributions using chemistry-climate and Earth system models such as the new Chemistry Climate Model Initiative (CCMI-2) and Coupled Model Intercomparison Project (CMIP6), observations, as well as contributions using novel statistical approaches (e.g. Machine, causal inference) to gain insights into composition changes, related feedbacks and theoretical studies.

Second session:
AS3.7:  Dynamics and chemistry of the upper troposphere and lower stratosphere (UTLS)

Convener: Felix Ploeger
Co-conveners: Tanja Schuck, Hella Garny, Harald Boenisch, Daniel Kunkel

Abstract: The composition of the upper troposphere and the lower stratosphere (UTLS) plays a key role in the climate system. Our understanding of the interactions between dynamics, chemistry and climate in this region is rapidly advancing thanks to both observational and modelling studies. In this session we invite studies of dynamical, transport and chemical processes determining the variability and long-term trends in the composition of the UTLS, and related impacts on radiation and dynamics. This particularly includes studies of upper and middle stratospheric as well as of tropospheric dynamics and chemistry affecting the UTLS. We encourage studies bringing together recent in situ and/or remote sensing observations and model simulations of different complexity (e.g., comprehensive climate models, chemistry transport models, idealized and conceptual models)