Glaciers/Ice Sheets Glaciers are made up of fallen snow that, over many years, compresses into large, thickened ice masses. An ice sheet is a dome-shaped glacier mass exceeding 50,000 square kilometers. The world's ice sheets are confined to Greenland and Antarctica.>>
	Gravity/Gravitational Field Gravity is the field around the Earth that can be measured by satellites. Changes in the gravity field are related to change or transportation of mass, which can provide information on ocean circulation, glacial melt, droughts or geodesy.   >>
	Ocean Circulation Ocean Circulation is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, the Coriolis force, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun. >>
	Ocean Heat Budget The Ocean Heat Budget consists of ocean heat gains and losses, including shortwave radiation from the sun, longwave radiation from the ocean, latent heat flux, sensible heat flux, and heat transfer by currents. How much heat the ocean absorbs and releases is significant to the global climate. >>
	Ocean Surface Topography Ocean Surface Topography is the height of the ocean surface relative to a level of no motion defined by the geoid, a surface of constant geopotential, and provides information on tides, circulation, and the distribution of heat and mass in the Earth’s global ocean.  >>
	Ocean Temperature Ocean Temperature is a measure of the energy in the ocean due to the motion of molecules. Depending on the sensor, spaceborne measurements give us an unprecedented global measurement of ocean temperatures from approximately 10 µm below the surface (infrared bands) to 1 mm (microwave bands) depths using radiometers.  >>
	Ocean Waves Ocean Waves are disturbances in the surface of the ocean. They can be created by wind, gravity, or other displacements of water. Satellites typically measure significant wave height, which is the average wave height of the highest third of waves in a given sample period.>>
	Ocean Winds Ocean Winds are defined as the motion of the atmosphere relative to the surface of the ocean. The most common reference height for near-surface ocean wind measurements is 10 meters above sea level. Active and passive satellite remote sensing provide high-resolution, near-surface ocean wind measurements over the ice-free ocean multiple times per day.  >>
	Salinity/Density Salinity is the saltiness, or dissolved salt content, of a body of water. Salinity varies due to evaporation and precipitation over the ocean as well as river runoff and ice melt. Along with temperature, it is a major factor in contributing to changes in density of seawater and therefore ocean circulation.   >>
	Sea Ice Sea ice forms within the polar oceans when the seawater temperatures reach the local freezing point. Sea ice moves by winds and currents and is subject to large-scale motion and local-scale deformation. The sea ice cover in the polar oceans play a fundamental role in the global climate and oceanographic system. >>
	Surface Water Surface Water is any body of water above ground, including streams, rivers, and lakes. It is a key component of the hydrologic cycle and provides various ecosystem services, including drinking water, agricultural irrigation, and habitat for aquatic plants and wildlife. >>