Utility of the United States National Ice Center's Interactive Multi-Sensor Snow and Ice Mapping System Data to View Arctic Variability

The mission of the United States National Ice Center (USNIC) is to provide global to tactical scale ice and snow products, ice forecasting, and related environmental intelligence services for the United States government. To achieve its mission for gridded operational ice and snow maps, the USNIC applies the Interactive Multisensor Snow and Ice Mapping System (IMS). This system provides analysts with the ability to interpretively and semi-automatically demarcate the location, depth, and concentration of snow and ice using satellite, in situ, and assimilated data.

IMS is a specialized software environment that provides data overlays from multiple sources to analysts for production of quality-controlled daily snow and ice maps over the Northern Hemisphere used by the numerical modeling community. IMS analysis has been produced since 1997 and operational at the USNIC since 2008. Since 2006, the National Snow and Ice Data Center’s (NSIDC) Multisensor Analyzed Sea Ice Extent (MASIE), in cooperation with the USNIC, uses the most recent full day of 4km data from the IMS to determine the amount of sea ice present. Analysts at the USNIC use a 3-day mean of this data to create a graph showing the trends in sea ice extent. A longer climatology of sea ice cover can be created with a more coarse resolution of 24km. The 24km gridded data encompasses a 20 year time period (February 1997 - present). Until sufficient 1km and 4km temporal coverage is created, the 24km coverage can serve as a proxy for climatological purposes. Yearly variation of Arctic sea ice can be seen by comparing a various combination of Arctic ice extent images and trends since 1997.