TWC Seminar: Speaker Dr. Christopher J. Crawford

Oak Ridge Associated Universities (ORAU) and Cryospheric Sciences Laboratory/615, NASA GSFC

Successive snow accumulation in cold continental regions during the hemispheric cool-season forms a seasonal snowpack. In arid climate zones, snowmelt-fed streamflow from high mountain basins modulates seasonal hydrologic variability and replenishes annual freshwater supplies to inland catchments on interannual-to-decadal timescales. Empirical evidence from in-situ measurements as well as climate model simulations suggests that mountain snowpacks are in decline across western North America; a result linked to warming surface temperatures during the latter half of the 20th century. Yet a systematic effort to examine mountain snowpack extent variability and change since the early 1970s as seen by Earth observing satellites remains quantitatively un-documented when framed within a western North America hydroclimate narrative.  In this talk, I summarize efforts to develop multi-sensor snow cover climate data records (CDRs) during the EOS era by using Landsat, MODIS, and VIIRS retrievals, and describe snow cover CDR design specifications, algorithm workflow and refinement, quality control standards, and error/uncertainty assessments. Snow cover CDR case studies from central Idaho, southwestern Montana, and western Wyoming are presented from the interior western United States with specific attention to multitemporal mapping, cross-sensor validation, and CDR fusion with ground-based measurements.
Speaker Bio:
Christopher is a NASA Postdoctoral Fellow in the Cryospheric Sciences Laboratory here at NASA Goddard. He joined Cryospheric Sciences this past August after finishing a NASA Earth and Space Science Fellowship and Ph.D. in the Department of Geography at the University of Minnesota.