Séminaire LATMOS mardi 15 mai 11H (Jussieu). Kevin W. Bowman (Jet Propulsion Laboratory, California Institute of Technology): "Observational constraints on climate forcing: perspectives from satellites, models, and assimilation"

Atmospheric composition is the primary driver of climate and environmental change from human activity. Well-mixed greenhouse gases such as carbon dioxide are linked to short-lived climate forcers
such as ozone through common combustion sources, chemistry, and eco-system processes. Consequently, policy studies are beginning to consider both air quality and climate impacts within an Earth
System context to develop global mitigation strategies. Satellite observations from instruments such as the NASA Tropospheric Emission Spectrometer play an important role in understanding the processes
controlling atmospheric composition as well as their attribution to specific sources. In conjunction with atmospheric models and advanced assimilation techniques, these data are providing constraints on
how changes in composition force both climate and air quality, setting the stage for effective mitigation strategies. We will show how ozone radiative forcing can be attributed to spatially resolved sources
and sinks through a combination of satellite-derived instantaneous radiative kernels (IRK) and adjoint modeling techniques. These IRK will also be used toevaluate ensemble chemistry-climate model
ozone predictions and their radiative forcing, providing a calibration point between historic change and future response of climate.