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Snow Water Equivalent

Snow Extent

Globsnow snow products

The GlobSnow project aims at creating temporally and spatially extensive snow products with well known accuracy characteristics. The snow products will be based on current state of the art algorithms that can be employed for global scale snow monitoring. Two snow parameters: snow extent (SE) and snow water equivalent (SWE) are produced within GlobSnow.

The snow products will be validated using an extensive ground truth database gathered from Canada, Scandinavia, Russia and the Alps. The consistency of the historical data sets will be investigated and characterized for different geographical regions. The snow products will be archived and distributed through ESA network and the data will be available for the User community free of charge.

The currently released prototype data sets have been made publicly accessible through a FMI hosted FTP-server; access information to the server can be acquired through Dr. Kari Luojus (firstname.lastname@fmi.fi).

Global areal snow extent -product (SE)

The areal snow extent product will be based on satellite-based optical data. It will include daily, weekly and monthly snow extent maps produced for Northern and Souther Hemispheres, excluding glaciers, Greenland, Antarctica and snow on ice (lakes/seas/oceans).

Main features for SE:
  • The long term SE data set will be generated for the years 1995 - 2010
  • The snow cover maps are produced as daily, weekly and monthly composites
  • ESA ERS-2 ATSR-2 and Envisat AATSR data are the main employed data sources
  • Areas with seasonal snow cover on both Northern and Southern Hemispheres are covered
  • The SE maps will be generated using WGS84 projection and a 0.01 degree (approx. 1km) spatial resolution
  • Demonstration of an operational near-real time SE mapping service will be conducted out at a later stage of the project

Snow water equivalent -product (SWE)

The snow water equivalent product will be based on the combination of satellite-based microwave radiometer and ground-based weather station data.

Main features for SWE:
  • The long term SWE data set will span the years 1978 - 2010
  • The snow cover maps are produced as daily, weekly and monthly composites
  • Nimbus-7 SMMR, DMSP SSM/I and Aqua AMSR-E are the main data sources, SSM/I for 1987 - 2002, AMSR-E for 2002-2010
  • Non-mountainous areas of Northern Hemisphere are covered
  • The SWE maps will be generated using EASE-Grid projection and a 25km spatial resolution
  • Demonstration of an operational near-real time SWE mapping service will be initiated on October 2010

More detailed descriptions are found within the project documentation accessible through user pages of the project.


Finnish Meteorological Institute