Discovery: WATCH VIDEO: How do we know for sure that our climate is changing? Using super-sensitive satellite measurements, scientists are developing a more sharply focused picture of what is happening to the ice mass of Antarctica — one of the 800-pound gorillas of global sea level rise. SEE ALSO: Century-Old Antarctic Station Shows Warming Year-to-year rises and falls in snow and ice accumulation in two key regions of West Antarctica — the Antarctic Peninsula and a coastal region along the Amundsen…