Future Satellite Observations of the Dynamics and Microphysics of Convection from the NASA Atmosphere Observing System (AOS)

Atmospheric convection plays a fundamental role in the vertical redistribution of atmospheric constituents, in driving atmospheric circulation, and in creating severe weather conditions that put life and property at risk. Cloud and precipitation processes in convection and their related release of latent heat are coupled to the rate of vertical air motion in convective updrafts and downdrafts. Observations of vertical air motion in convection have generally been confined to suborbital observations in limited areas and periods of time, but understanding the global distribution of convection is very much needed. The EarthCare mission is expected to provide Doppler-derived vertical air motions in weaker convective clouds and the INCUS mission will obtain measurements in weak to moderate convection (and the upper part of intense convection) using a time-differenced reflectivity approach to infer vertical air motions. The Atmosphere Observing System (AOS), a NASA mission in response to the Aerosols and Clouds, Convection, and Precipitation (CCP) designated observables from the 2017 NASA Earth Science Decadal Survey, will advance understanding of convection globally by providing Doppler radar measurements over a broad spectrum of convective cloud systems in combination with a suite of sensors providing information on aerosol-cloud-precipitation interactions.

AOS plans to obtain measurements in two orbital planes. In a 55° inclined orbit, a JAXA Ku-band Doppler radar will provide radar reflectivity and velocity measurements in moderate to strong convective systems over varying times of day, combined with CNES time-differenced (over ~2-minute intervals) passive microwave brightness temperatures that will characterize the rate of change of ice water path and anvil size as well the vertical flux of ice mass. In a polar orbiting observing system, AOS will provide a cloud-profiling Doppler radar, with the exact approach currently under study. This presentation will provide the latest information on AOS capabilities.