The Multisensor Analyzed Sea Ice Extent - Northern Hemisphere (MASIE-NH) products provide measurements of daily sea ice extent and sea ice edge boundary for the Northern Hemisphere and 16 Arctic regions in a polar stereographic projection at both 1 km and 4 km grid cell sizes. MASIE products include an ASCII text file of sea ice extent values in square km for each Arctic region, time series plots, and image files that visually show where the sea ice is.Note: MASIE may look like several other sea ice products distributed at NSIDC and elsewhere, but its source data from the U.S. National Ice Center (USNIC) and intended uses are different. If intended and appropriate uses of the data are not clear after reading the documentation, please contact NSIDC User Services.