Timothy J. Lang (ST11) is a coauthor on an article called “Diurnal Cycle of Tropical Oceanic Mesoscale Cold Pools,” which was recently accepted in the Journal of Climate. This study used ocean vector wind data from NASA RapidScat, which operated on the International Space Station (ISS) during 2014-2016, to examine the diurnal cycle of tropical maritime cold pools, which are pockets of cold air caused by convection. Cold pools are important for organizing convection and modulating energy exchange between the air and sea.
First, the study applied the gradient feature (GF) technique developed by the University of Illinois in collaboration with Marshall Space Flight Center (MSFC) to identify cold pools from RapidScat scatterometer measurements. These GFs were validated as convectively produced cold pools via comparison to spaceborne Advanced Scatterometer (ASCAT) and in situ buoy observations. In this first-of-its-kind study of the global diurnal behavior of cold pools, it was found that overnight cold pools tend to be larger and stronger, reflecting heavy precipitation from organized mesoscale systems, while during the afternoon cold pools are weaker, reflecting the influence of weaker cumulus congestus clouds (Fig. 1). The study also established a link between bulk cold pool properties (e.g., number, size) and atmospheric water vapor, which has important implications for the forthcoming Air-Sea interface and Atmospheric Profile (ASAP) mission, which launches to the ISS later this year and will provide simultaneous observations of ocean vector winds and atmospheric water vapor.