Determination of the dominant spatial modes of terrestrial snowcover over North America using passive microwave derived data

摘要

Passive microwave derived measures of snow water equivalent (SWE)provide an excellent means of monitoring snow cover because of a broadspatial resolution, daily orbital coverage, and all weather imagingcapabilities. Combining analysis of this remotely sensed data withgridded atmospheric pressure and temperature data will allow improvementin the understanding of the complex interactions between seasonalterrestrial snow cover and overlying atmospheric systems. This studyutilizes one winter season of Special Sensor Microwave/Imager (SSM/I)passive microwave SWE imagery and National Meteorological Center (NMC)gridded atmospheric data to examine an analysis methodology whichutilizes both principal components analysis (PCA) and canonicalcorrelation analysis (CCA) to link surface and atmospheric processes.The short time series was limited by data availability, but is stilluseful for isolating the strengths and weaknesses of the methodology,which can be applied in the future to the ever increasing time series ofSWE imagery. Results show a meridional circulation pattern is linked toperiods of snow accumulation, while a zonal circulation patterncorresponds to persistent snow ablation