"In March, the Arctic sea ice pack is supposed to reach its greatest extent - but this year it's far below average, off by an area about the size of Texas and New Mexico combined. Satellite observations currently reveal how much of the ocean surface is covered by ice, but there is another critical measurement to make. Researchers are already anticipating using NASA's Ice, Cloud and land Elevation Satellite-2, or ICESat-2, to measure sea ice in the third dimension.
Satellites have been continuously measuring sea ice since 1979, and have mapped the downward trend of ice extent. Determining the thickness of the remote sea ice pack, however, is difficult with existing tools. And it's an essential measurement. Thicker ice is more resilient to storms, and can take years to build up.
Changes in the depth of sea ice alters the water's salinity and temperature, which can alter oceanic and atmospheric currents. Sea ice also acts as a cap on the ocean - insulating it from the atmosphere - and plays a key role in cooling down the planet."