MODIS/Aqua Sea Ice Extent and IST Daily L3 Global 4km EASE-Grid Day (MYD29E1D) data set contains fields for sea ice by reflectance and Ice Surface Temperature (IST). Each data granule covers the entire globe with two separate arrays of 4501 x 4501 pixels: one for the Arctic and one for the Antarctic. The MODIS sea ice algorithm uses a Normalized Difference Snow Index (NDSI) modified for sea ice to distinguish sea ice from open ocean based on reflective and thermal characteristics. Data are stored in HDF-EOS format, and are available from 4 July 2002 to present via FTP. Data can also be obtained in GeoTIFF format by ordering the data through the Data Pool.