On 18 April 2022, the file names for this data set were updated. Please update any scripts you have to use the new file names. See the User Notice: IMS Daily Northern Hemisphere Snow and Ice Analysis Files Renamed for full details.
Data Set ID: 
G02156

IMS Daily Northern Hemisphere Snow and Ice Analysis at 1 km, 4 km, and 24 km Resolutions, Version 1

This data set provides maps of snow cover and sea ice for the Northern Hemisphere from February 1997 to the present from the United States National Ice Center (USNIC). USNIC analysts produce these using the Interactive Multisensor Snow and Ice Mapping System (IMS). Maps are derived from a variety of data products including satellite imagery and in situ data. The data are provided in ASCII text and GeoTIFF formats in three different resolutions: 1 km, 4 km, and 24 km.

Note: The IMS product is considered an operational product; however, USNIC, who creates this product, does not guarantee availability or timely delivery of data via the NIC Web server. NSIDC, as the data archive, does not guarantee availability of this product via the NSIDC Web server. These servers should not be used to support operational observation, forecasting, emergency, or disaster mitigation operations, either public or private. Users with real-time operational needs should visit the USNIC Web site and contact the USNIC Liaison to request access to their operational server.

This is the most recent version of these data.

Version Summary: 

Initial release

COMPREHENSIVE Level of Service

Data: Data integrity and usability verified; data customization services available for select data

Documentation: Key metadata and comprehensive user guide available

User Support: Assistance with data access and usage; guidance on use of data in tools and data customization services

See All Level of Service Details

Parameter(s):
  • SNOW/ICE > ICE EXTENT
  • SNOW/ICE > SNOW COVER
Data Format(s):
  • GIF
  • NetCDF
  • GeoTIFF
  • ASCII
Spatial Coverage:
N: 90, 
S: 0, 
E: 180, 
W: -180
Platform(s):AQUA, DMSP, DMSP 5D-3/F17, GOES-10, GOES-11, GOES-13, GOES-9, METEOSAT, MSG, MTSAT-1R, MTSAT-2, NOAA-14, NOAA-15, NOAA-16, NOAA-17, NOAA-18, NOAA-N, RADARSAT-2, SUOMI-NPP, TERRA
Spatial Resolution:
  • 24 km x 24 km
  • 1 km x 1 km
Sensor(s):AMSU-A, ATMS, AVHRR, GOES I-M IMAGER, MODIS, MTSAT 1R Imager, MTSAT 2 Imager, MVIRI, SAR, SEVIRI, SSM/I, SSMIS, VIIRS
Temporal Coverage:
  • 5 February 1997
(updated daily)		Version(s):V1
Temporal Resolution1 dayMetadata XML:View Metadata Record
Data Contributor(s):U.S. National Ice Center.

Geographic Coverage

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As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

U.S. National Ice Center. 2008, updated daily. IMS Daily Northern Hemisphere Snow and Ice Analysis at 1 km, 4 km, and 24 km Resolutions, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: https://doi.org/10.7265/N52R3PMC. [Date Accessed].

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How To

How can I plot IMS-24km ASCII data using General Mapping Tools (GMT)?
There are two "tricks" to using this dataset with GMT: reading the data into a GMT grdfile, and knowing the projection to use when plotting data over the gridded image. First, the ASCII files have a 30-line header, then single-digit values all strung together. GMT's xyz2grd command needs the data... read more
How to Import IMS ASCII Data Into ArcGIS
This article describes the process for importing IMS ASCII data, in 1, 4, and 24km resolutions into ArcGIS. This article was produced using ArcMap v10.5. For the 24km resolution data, there is both packed and unpacked versions of the data. For packed... read more
How to reproject the IMS 1km or 4 km GeoTIFFs to geographic latitude/longitude
If you need to reproject the IMS 1 km or 4 km GeoTIFFs to geographic latitude/longitude, we recommend using the Geospatial Data Abstraction Library (GDAL). Instructions for downloading and installing it can be found here: https://gdal.org/... read more

FAQ

Are there open source tools available for the IMS dataset?
Yes, one user of IMS has created and made available a suite of Python tools. Code examples and tutorials for spatial subsetting, pixel area calculations, timeseries construction and concatenation, and plotting can be found on this external website: ... read more
Access complete Knowledge Base

Questions? Please contact:
NSIDC User Services
Phone: 1 303 492-6199
Email: nsidc@nsidc.org