August 16, 2011

Warmer Global Temps Thinning Arctic Ice Pack

In three decades of recording Arctic Ocean sea ice, the National Oceanographic and Atmospheric Administration (NOAA) on Monday reported that in July 2011 the sea ice hit its lowest monthly recorded level.

Sea ice in the Arctic covered an average 3 million square miles during July, the lowest measurement for that month since the NOAA started keeping such records in 1979. The July 2011 figure is 81,000 square miles smaller than 2007's July record low and about 22 percent below the average for the month, NOAA reported.

While the month of July saw record ice loss, the shrinkage slowed in the last half of the month, as cooler weather left a "thinner but more extensive ice cover" over the Arctic, according to data from the National Snow and Ice Data Center (NSIDC).

The decline of the sea ice has allowed ships to cross the Arctic along the Russian coast with some aid from icebreakers and could open up the Northwest Passage along the shores of North America in the coming weeks, NSIDC reported.

NOAA also reported that overall global temperatures for the month of July were the seventh-warmest on record since records started being kept in 1880.

The average temperature for the month worldwide was 61.4 degrees Fahrenheit, about 1 degree higher than the 20th century July average, according to NOAA.

In the United States, a heat wave that pushed through much of the Midwest and southern Plains drove the July average to 77 degrees -- the fourth-warmest July on record. Northern Europe and eastern and western Russia also saw warmer-than-average temperatures in July. Central Russia, western Europe, the western United States and southwestern Canada saw a cooler July than usual, NOAA reported.

Also in the NOAA report, ocean surface temperatures for July were 0.85 F warmer than the 20th century average of 61.5 F. That figures makes the ocean surface temperature the 11th warmest July on record. The warming was most pronounced across Baffin Bay and the Labrador Sea in the Northern Hemisphere high latitudes and in the north central and northwestern Pacific Ocean.

The combined global land and ocean average surface temperature for the January-July period was 0.92 F warmer than the 20th century average of 56.9 F, making it the 11th warmest period on record.

NOAA's Climate Prediction Center reported that neither El Niño nor La Niña conditions were present during July 2011. The firm expects ENSO neutral conditions to continue into the Northern Hemisphere fall 2011, with an equally likely chance of ENSO-neutral or La Niña conditions thereafter.

The NSIDC is funded by NOAA, NASA and the National Science Foundation.


Image 2: Global surface temperature Anomalies - July 2011. Credit: NOAA


On the Net: