Authors: Dorothy Hall*, University of Maryland, George A. Riggs, SSAI, Nicolo E. DiGirolamo, SSAI, Donal S. O'Leary, University of Maryland
Topics: Cryosphere, Remote Sensing, Climatology and Meteorology
Keywords: snow cover, snowmelt, MODIS, VIIRS
Session Type: Paper
Start / End Time: 8:00 AM / 9:15 AM
Room: Virtual Track 2
Presentation File: No File Uploaded
Optical remote sensing has been used widely to observe snow cover globally, but cloud cover presents challenges for identifying the timing and extent of the arrival and disappearance of snow cover. To address the need for daily cloud-reduced or cloud-free snow products, a cloud-gap filled (CGF) snow-cover extent (SCE) product has been developed and is available in MODerate-resolution Imaging Spectroradiometer (MODIS) Collection 6.1 and Visible Infrared Imaging Radiometer Suite (VIIRS) Collection 2, with a time series of each product expected to be available in 2020. CGF snow maps allow for improved analysis of snowmelt dynamics. Here we show snow-cover depletion curves and snowmelt-timing maps from the Great Salt Lake (GSL) Basin, Utah, in the Wasatch and Uinta Ranges using MODIS (MOD10A1F) and VIIRS (VNP10A1F) snow-cover products. In general, the MODIS and VIIRS SCE maps show excellent correspondence. Our results show areas with statistically-significant trends of earlier snowmelt in the GSL Basin since 2000. This is consistent with increasing air temperatures, and in particular, increasing nighttime air temperatures, as determined from 26 meteorological stations in the GSL Basin. We also provide an evaluation of uncertainties in the MODIS Terra and VIIRS SCE maps, in the context of developing an Environmental Science Data Record (ESDR) for global snow cover. A moderate-resolution ESDR will extend the SCE data record from the beginning of the MODIS era in 2000, into the VIIRS era through the early 2030s, and perhaps beyond.