Ground Validation

On a Wednesday afternoon in June, a severe storm outbreak spawned huge thunderstorms across Iowa and western Illinois. NASA's Polarimetric precipitation radar was in place to scan the storms as they swept through the region. "It's unbelievable out here," Walt Petersen of NASA's Wallops Flight Facility in Virginia wrote in an email dispatch from Traer, Iowa. There, two NASA radars were stationed as part of the Iowa Flood Studies field campaign, which Petersen led, for the Global Precipitation Measurement, or GPM, mission. Caption: A cluster of rain gauges and soil moisture sensors deployed in...

In total, 25 events were identified with two events classified as “clear air” flights conducted by the DC-8 to sample land surface emission characteristics. Table 4 summarizes case date and time, event type, and airborne data collection during the field project. Event total SWE amounts represent manual measurements taken by a Tretyakov gauge located inside a DFIR wind shield at CARE. Precipitation types are characterized as rain (R), snow (S), or mixed precipitation that could include ice pellets (R/S). Synoptic context/regime(s) were determined from the daily synopsis produced by the project...