Data are obtained via remote sensing from satellites and a network of sea ice buoys. Satellites provide daily information on ice extent and movement. The radiant emission patterns of the ice are obtained by the satellite's sensor. As sea ice ages, its emission properties change. In younger ice, the remaining trapped brine has not completely drained away.
Multiyear ice is known to have about two parts per thousand salt.
Buoys are also used to monitor ice movement and characteristics of the polar sea ice. These stations are designed to monitor sea ice motion and transmit the information to satellites automatically. The original purpose of these buoys was to provide ships in the Arctic with information on changes in ice cover and ice movement. Their additional benefit to scientists is the acquisition of data on ice pressure and temperature, recording of geographic position in the Arctic, and velocity at which sea ice moves. Steele has used satellite and buoy data to develop a model of the Arctic Ocean's freshwater balance.