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The Timing and Frequency of Rain on Snow Events in Alaska
Caleb
Pan, University of Montana, caleb.pan@mso.umt.edu
Rain-on-snow (ROS) affects many of the physical properties of a snow pack including energy content, depth, density and grain size. In northern latitudes ROS, wet snow and the icing events that follow, effect ecosystem processes at multiple scales including, wildlife movement, carbon cycling, human transportation, and hydrology. Here we present a new dataset for Alaska, USA that has been developed from satellite optical and passive microwave (PM) remote sensing. Our detection uses a spectral gradient ratio of calibrated AMSR-E and AMSR-2 36.5 GHz and 19 GHz brightness temperatures mapped to a 6-km resolution on a polar EASE-grid projection. Our classification includes snow cover extent (MOD10A2) and a DEM as additional ancillary inputs. Data were evaluated against in-situ observations of ROS events using a 2-tier validation process. Spatial and temporal trends of wet snow were evaluated over the recent satellite record (2002-2016) in relation to the regional climate divisions. These data demonstrate an accuracy of 85.9 % between observed ROS and wet snow PM returns with strong linkages between regional patterns and periods of above normal temperatures across Alaska. Associated Project(s): Poster Location ID: 110 Session Assigned: Carbon Dynamics
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