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 of limited areas and periods of time, but understanding the global distribution of convection is very much needed.

 

The NASA Atmosphere Observing System (AOS) was formulated based on the NASA 2017 Earth Science Decadal Survey to address key objectives tied to aerosols, clouds, convection, and precipitation. As of March 2024, the AOS constellation consists of four individual projects: 1) AOS-Storm, in partnership with JAXA and CNES, flying in a 55° inclined orbit and focusing on convective precipitation, vertical air motions, and convective ice cloud properties; 2) AOS-Sky, a satellite carrying a suite of passive sensors including a multi-angle polarimeter, passive microwave radiometer, and thin ice cloud far infrared imaging radiometer flying in tandem with a CSA-provided spacecraft (called HAWCsat) carrying aerosol and moisture limb imagers; 3) an Italian Space Agency led mission, in partnership with NASA, carrying a multi-frequency elastic backscatter lidar with Raman channels for measurement of aerosol, cloud, ocean, and land properties; and 4) an expected cloud profiling radar to be competed as part of an announcement of opportunity.

 

This talk will focus on the AOS-Storm project consisting of the JAXA Precipitation Measuring Mission (PMM) and the CNES Convective Core Observations through MicrOwave Derivatives in the trOpics (C²OMODO) mission, with NASA providing a spacecraft bus for one of the CNES radiometers and launch of both satellites.  The PMM mission includes a JAXA-provided spacecraft and Ku-band Doppler radar that will provide radar reflectivity across a 255-km swath (similar to TRMM and GPM) and Doppler velocity measurements at nadir in moderate to strong convective systems. The CNES C²OMODO mission consists of two identical passive microwave radiometers (channels near 89, 183, and 325 GHz) flying in tandem with a temporal spacing expected to be in the 30-120 second range. The time-differenced passive microwave brightness temperatures will characterize the rate of change of ice water path and anvil size as well as the vertical flux of ice mass. We will highlight recent simulations of expected performance for measurements of vertical air motions and ice water path in convective clouds.