New Global Snow and Ice Dataset for Reanalysis and Climate Studies

Long-term temporally and spatially consistent estimates of daily snowpack properties over seasonally snow-covered land are needed for many applications including evaluation of climate models and re-analysis schemes, numerical weather prediction, and assessment of freshwater availability. In this project we have developed a new global multidecadal dataset which provides information on three major snow pack properties the Snow Cover Extent (SCE), Snow Water Equivalent (SWE) and Snow Depth (SD) as well as on the Ice Cover Extent (ICE). Information on the snow and ice extent is derived from satellite observations in the optical and microwave spectral bands. Snow depth and snow water equivalent are estimated from in-situ snow depth data blended with the snow depth from satellite observations in the microwave. Daily maps of the snow/ice extent, snow depth and snow water equivalent are generated at 4 km resolution. The dataset is routinely updated with the most recent estimates and extends back to mid-1987.

In the presentation we provide details on the data processing algorithms, give examples of the new product and present estimates of its accuracy. Long-term trends in the snow extent derived from the new dataset are compared with the available coarse resolution snow cover trends and climatology based on the NOAA interactive snow product. Snow depth maps are validated against in situ observations while hemisphere-wide estimates of the cumulative snow water mass inferred from the SWE maps are compared with other remote sensing products and model data.