Study Links Low Arctic Sea Ice Levels to Drier Winters in the U.S.

In its 4 May 2009 update, the National Snow and Ice Data Center reports:

"A new study suggests that Arctic ice extent at the end of summer can affect precipitation at lower latitudes the following winter. Jennifer Francis from Rutgers University and colleagues compared winter weather following summers with below-average ice extent, to weather following summers with above-average ice. The researchers found that low summer sea ice extent is linked to drier winters over much of the U.S., Scandinavia, and Alaska, and wetter winters in the northern Mediterranean, Japan, and the Pacific Northwest. The study showed that extensive ice loss in summer warmed the Arctic atmosphere during autumn. This warmth weakened the storm track that encircles the northern hemisphere, affecting weather patterns far away from the Arctic. As sea ice continues to decline in summer, these influences will become more prominent."

See the figure below. The study, “Winter Northern Hemisphere weather patterns remember summer Arctic sea-ice extent,” is by J.A. Francis, W. Chan, D. J. Leathers, J. R. Miller, and D. E. Veron and was published in the April 209 issue of Geophysical Research Letters. For an overview of the Arctic science, see: Arctic Climate Impact Science — an update since ACIA (April 2008). See also our press release, Arctic Warming Threatens Future Of The Planet (16 December 2008)

This map shows regions of above- and below-average precipitation observed in winter, following summers with very low Arctic sea ice extent.
© National Snow and Ice Data Center, courtesy J. Francis, Rutgers University