The USNIC Great Lakes Ice Chart Web Service is made up of Analysis polygon features classes. The Great Lakes Analysis GIS Shapefile and KMZ file are created and loaded into CloudGIS Database for use in the USNIC Great Lakes Ice Chart Web Service from the North American Ice Service daily Great Lakes Analysis coordinated between the U.S. National Ice Center and Canadian Ice Service. The daily Great Lakes Analysis contains SIGRID-3 information on ice conditions that are separated into various fields including total ice concentration, ice types and their respective partial concentrations, and floe size, among others. This analysis is updated daily, valid at 18 UTC, and available at https://usicecenter.gov/Products/GreatLakesData.

The SIGRID-3 vector archive format is one of the World Meteorological Organization (WMO) standards for archiving digital ice charts. The U.S National Ice Center (USNIC) creates SIGRID-3 ice charts on a regular basis for a number of regions in the Arctic, Antarctic, Great Lakes and U.S. East Coast. These SIGRID-3 files have two main components: the shapefile containing the ice analysis information (ice polygons and related attributes) and the metadata describing the ice analysis data under the SIGRID-3 format. Current and legacy data for many USNIC products can be found through the USNIC website (https://usicecenter.gov/), the National Snow and Ice Data Center (http://nsidc.org/) or, for the Great Lakes specifically, through the Great Lakes Environmental Research Laboratory (http://www.glerl.noaa.gov/). The joint North American Ice Service analysis from which this USNIC product derives represents ice conditions valid at approximately 1800 UTC but is analyzed from imagery over the preceding 24hrs. Imagery utilized includes synthetic aperture radar (SAR), geostationary imagery such as GOES, polar orbiting imagery such as VIIRS, other optical or infrared sensors prioritized by regency and image quality, and application of an understanding of conditions gained from surface stations, radar, and forecast weather conditions.

Update Frequency: Daily at 1800UTC

Link to metadata

For questions about the underlying data or other ice datasets, please see https://usicecenter.gov/Contact.

Questions/Concerns about the service, please contact the DISS-GIS team.

Time Information:

This service is not time enabled.