Observing the dynamics of deep convection using a tandem of spaceborne microwave radiometers

Deep convection plays a fundamental role in the climate system by transporting from the lower layers of the atmosphere to the free troposphere, air, water and momentum. Although its study has been the subject of intense and rich scientific activities for decades, our ignorance of the vertical distribution of convective movements in the heart of convective cells is today an important scientific and operational obstacle. Only space-borne observations can meet the needs in documentation necessary to progress on the science of the water and energy cycle and simultaneously improve numerical forecasting systems. Pending the emergence (hypothetical) of microwave missions in geostationary orbit with high repeatability (~ 1 minute), an approach based on satellite constellations in convoys could provide a first response.

The “Convective Core Observations through MicrOwave Derivatives in the trOpics”, or C²OMODO for short, proposes to rely on 2 passive microwave radiometers with a multispectral sampling of the 183 and 325 GHz lines in a mini-train of 2 satellites. The time-spacing of 60 to 180sec between the 2 swaths encompasses information on the updraft motions of hydrometeors, and is thus used to characterize the intensity and the size of individual updrafts in deep convective systems.

We will present this original observational strategy, associated to the NASA / AOS general framework, as well as its expected added-value for the characterization of deep convection.