Observing & Predicting

Global sea ice thumbnail

NASA ice expert Claire Parkinson does the math on global sea ice and confirms that small gains around Antarctica do not cancel out large losses in the Arctic.

Tuesday, September 1, 2009

  •  The Sun is the main source of power for the Earth's climate machine. Space-based measurements, begun in 1978, indicate Earth receives an average of 1,361 W/m<sup>2</sup> of incoming sunlight, and the amount varies by about one-tenth of a percent over the course of the 11-year solar cycle.