Cold Land Processes Experiments (CLPX) 2002-2003

Snow and ice cover affect human activity in a variety of ways, impacting transportation, agriculture, fresh water availability, safety, and recreation. Snow cover also plays a major role in weather and global climate, modulating radiation feedback, boundary layer stability, and surface heat and moisture fluxes. Determination of the amount of snowpack through current means is, however, a time consuming task requiring either direct sampling or low-altitude airborne gamma emission measurements - both of which are limited in their areas of coverage and their statistical representativeness. The development of either airborne or spaceborne methods for wide-area imaging of snowpack properties such as snow water equivalent, grain size, and snow extent is an important goal for both weather and climate prediction applications, and the central focus of the joint NOAA-NASA Cold Land Processes Experiment (CLPX).

As part of a major field campaign involving one of the most intensive snow sampling efforts undertaken within the U.S., NOAA's Environmental Technology Laboratory has fielded the primary airborne sensor for CLPX during 2002 and 2003, the NOAA Polarimetric Scanning Radiometer. The PSR was operated in February 2002 on board of the NASA DC-8 aircraft and in February and March 2003 on board the NASA P-3 aircraft to provide the first high-resolution airborne microwave imagery of snowfall over three sites within the Colorado Rocky Mountains. Data from the PSR instrument are being used to develop snowfall change detection algorithms for use in NWS models for mapping snowpack properties throughout the winter season. The snowpack data will ultimately provide improved prediction of hydrological runoff, avalanche danger, and regional weather and climate trends. The NOAA PSR - the world's only airborne conical imaging radiometer - also provides a unique means of simulating what a future NASA cryospheric satellite would see, and provides valuable data for calibrating the NASA AMSR-E sensor on the EOS Aqua satellite.