This data set is only available for a restricted user group, please contact us if you want to access these data.
RESTRICTED only accessable in ZMAW net or via CliSAP login What does that mean?
Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I) data have been used to produce a SWE data set gridded onto a Lambert-Azimuthal Equal Area grid with 25 km grid resolution. The SWE data available here have been computed using re-processed brightness temperature observations that have been corrected in advance for inter-sensor differences. The data set includes monthly values of SWE and its standard deviation, together with the number of days (within a month) with snow cover in the respective grid cell.
The documentation the used approach, the methods used to optimize the data set including the error estimation, and a few aspects about the validation.
We note that some regions are subject to large discrepancies between the observed and the retrieved SWE values. Reasons for this are given below in sections "data quality" and "references".
The maps on top of this page exemplify the SWE distribution in the Northern Hemisphere for the months 11/2006 to 04/2007.
Coverage, spatial and temporal resolution
Period and temporal resolution:
Coverage and spatial resolution:
Data of the Southern Hemisphere can be provided upon request.
The data set contains information about the uncertainty in the retrieved SWE. However, users should be aware of additional error sources; the approach itself (cannot be adapted to local snow property changes as e.g. a high fraction of depth hoar) as well as the coarse spatial resolution (grid resolution is 25 km) can cause further uncertainties if not even a bias.
Furthermore, problems arise in forested areas and mountains, in regions covered with many lakes and in areas with highly varying snow properties (dry <--> wet) or a high fraction of depth hoar relative to the total snow depth.
We recommend the publications listed in references down below for further reading.
NSIDC User Services
Please cite usage of this data as follows:
Armstrong, R. L., M. J. Brodzik, K. Knowles, and M. Savoie, 2007, Global monthly EASE-Grid snow water equivalent climatology, Boulder, CO: National Snow and Ice Data Center. Digital Media, distributed in netCDF format by the Integrated Climate Data Center (ICDC, http://icdc.zmaw.de) University of Hamburg, Hamburg, Germany.