December 30, 2011

In the 2011 Arctic Report Card, scientists report that the bright white surface of the Greenland Ice Sheet has grown less reflective. The darker surface absorbs more sunlight, accelerating melting.

July 10, 2011
April 14, 2011

Arctic sea ice extent for the month of March was the second lowest in the satellite record. Ice cover at winter maximum continues to be dominated by young, thin ice.

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. 

An interactive that illustrates the relationships between the axial tilt of the Earth, latitude, and temperature. Several data sets (including temperature, Sun-Earth distance, daylight hours) can be generated.

This short animation compares graphs of the natural variation in the sun's energy striking the upper atmosphere vs global surface temperature over a 30-year period to make the point that natural variations do not account for the rising trend line in surface temperatures.

In this worksheet-based activity, students review global visualizations of incoming sunlight and surface temperature and discuss seasonal change. Students use the visualizations to support inquiry on the differences in seasonal change in the Northern and Southern Hemispheres and how land and water absorb and release heat differently. The activity culminates in an argument about why one hemisphere experiences warmer summers although it receives less total solar energy.

This NASA video discusses the impacts of the sun's energy, Earth's reflectance, and greenhouse gases on the Earth System.