Snow water equivalent for the Northern Hemisphere from 1979 to present derived from satellite observations

Snow water equivalent (SWE) is an important variable indicating the amount of accumulated snow on land surfaces. SWE describes the amount of liquid water in a snowpack that would be formed if the snowpack was completely melted. This dataset is useful for monitoring snow conditions, freshwater storage, and climate studies. It provides daily estimates of SWE for the Northern Hemisphere from 1979 to present derived from passive microwave radiometer (PMR) measurements onboard polar-orbiting satellites. The SWE retrieval algorithm combines information from satellite-based microwave radiometer and optical spectrometer observations with ground-based weather station snow depth (SD) measurements and produces daily hemispherical scale SWE estimates. The original algorithm to derive SWE was developed within European Space Agency (ESA) GlobSnow and ESA Climate Change Initiative (CCI) Snow. The adapted production scheme for this Copernicus Climate Change Service (C3S) products includes latest improvements in the algorithm.
The Climate Data Record (CDR) on SWE is produced on a daily and monthly basis. Its information is provided for terrestrial non-mountainous regions of the Northern Hemisphere [0S; +80N, -180W, +180E], excluding glaciers and Greenland. The CDR is available in a regular 0.1° x 0.1° latitude-longitude grid. The SWE estimates are complemented with statistically derived uncertainty estimate accompanying each SWE estimate.
The CDR of snow water equivalent are retrieved from spaceborne observations of multiple polar orbiting satellites available since 1979, allowing for consistent and long-term monitoring winter conditions on snow. The algorithm retrieval scheme consists of the full processing chain from Level-1 PMR K- and Ka-band measurements at native satellite Equal-Area Scalable Earth (EASE) Grid projection to the final Level-3 physical data provision. Thus, variables are available at uniform space-time grid scales and help foster new developments of applications or services as well as assimilation of SWE observations to climate and forecast models.
This data is produced on behalf of the C3S by Finnish Meteorological Institute.