How accurately can passive microwave (PMW) sensors detect convective precipitation? That is the question posed in a paper by ESSIC/CISESS Scientists Lei Ji and Veljko Petković and Naval Postgraduate School’s Marko Orescanin published in the Journal of Geophysical Research: Atmospheres.
They use eight years (2015–2023) of collocated observations from the Global Precipitation Measurement mission Core Observatory Microwave Imager (GMI) and Ku‐band Precipitation Radar (KuPR) in their analysis, with the latter serving as the reference dataset. Two‐meter temperature (T2m) and total column water vapor (TCWV) from the ERA5 reanalysis are used to describe environmental conditions. The standard deviation of the difference between KuPR and GMI convective volume fractions (CVFs) quantifies the PMW CVF uncertainty.
They report that over the ocean, convective precipitation is generally underestimated by the PMW product except when there is plentiful water vapor (TCWV > 60 mm) or high surface temperatures (T2m > 304 K). Over land, the PMW product is generally overestimated but tends to be underestimated under relatively low water vapor and surface temperature conditions (TCWV < 45 mm and T2m < 285 K). These new insights, among others, into regional precipitation characteristics will be instrumental in improving the operational PMW algorithm.
