Low Clouds Aid Arctic Sea Ice Loss

August 1, 2011 — Click on image to enlarge.

August Highlights



Major Findings

  1. Terra/MISR data reveals a significant increase of low cloud cover in October during 2000-2010, the largest in the daylight Arctic months (March-October), and the result is consistent with CALIPSO lidar observations since 2006.
  2. The regions with the largest October low cloud increase collocate with where most sea ice loss occurred in Sep.
  3. MISR cloud observations support the theorized positive ice-temperature-cloud feedback, whereby more open water in the Arctic Ocean increases summer absorption of solar radiation, and subsequent evaporation, which leads to more low clouds in autumn. Trapping longwave radiation, these clouds effectively lengthen the melt season and reduce perennial ice pack formation, making sea ice more vulnerable to the next melt season.