GMASI 2km Snow and Ice Maps since 2007
--------------------------------------

This directory contains daily maps, map images and associated seasonal, yearly and multiyear statistics of the global snow and ice cover at 2 km spatial resolution 

The dataset has been derived with the operational GMASI Enterprise algorithm which was applied to historical satellite data back to 2007. 
The algorithm uses combined satellite observations and the visible/infrared (METOP AVHRR) and in the microwave spectral bands (DMSP SSMI/SSMIS)

The dataset includes daily global maps of snow and ice cover, monthly and yearly statistics on the snow and ice cover duration as well as 
multiyear mean annual and monthly snow and ice duration. All products are derived at 2 km spatial resoltuion.

Daily snow and ice maps are created on a geographical (latitude-longitude) grid with 0.02 degree grid cell size, west to east and north to south orientation with the uppor left corner of the image located at 90N, 180W. Data files are provided in NetCDF format. 

The dataset covers the time period from the beginning of 2007 to the middle of 2025. For later products please use operational GMASI Enterprise snow/ice cover maps
available at https://www.star.nesdis.noaa.gov/pub/smcd/emb/snow/gmasi_enterprise_2km_operational/ or from NOAA CLASS at https://www.aev.class.noaa.gov/saa/products/catSearch (search for Snow and Ice products, SNOW_ICE)

At this time daily snow/ice maps since the year 2020 are avaialble here. For earlier data (2007-2019) please contact peter.romanov@noaa.gov. 
Snow and ice occurence statistics derived from daily products will be added to this site later.

Content of subdirectories

dailymaps:           Daily maps of snow and ice cover since Jan 1, 2007. Maps are currently avaialble till July 15, 2025 
multiyear_means:     Multiyear mean annual and monthly snow cover duration data (2007-2024).  Data will be added later
yearly_statistics:   Annual snow and ice duration, 2007-2024. Data will be added later
monthly_statistics:  Monthly snow and ice occurrence, 2007-2024. Data will be added later.