Ice-Capped Greenland Feels the Heat with North Atlantic Sea Surface Temperatures far Above Normal

Newly released October data on sea surface temperatures (SSTs) in the North Atlantic show that temperatures were far above normal around southern Greenland.  The data comes days after NOAA released its annual Arctic Report Card saying "Greenland climate in 2010 is marked by record-setting high air temperatures, ice loss by melting, and marine-terminating glacier area loss."

North Atlantic Sea Surface Temperature Anomalies, October 2010.  Source: National Oceanic and Atmospheric Administration (NOAA)

Above: North Atlantic sea surface temperature anomalies, October 2010 (relative to 1971-2000 average).  Source: National Oceanic and Atmospheric Administration (NOAA)

NOAA released last week the figure above showing (in red areas) where SST's were far above normal.  Also last week, the UK Met Office's Hadley Centre released the map below of October 2010 SST anomalies showing record temperatures (indicated by the plus signs) around southern Greenland and over areas far to the west.

Sea surface temperature anomalies, October 2010. Source: UK Met Office Hadley Centre.

Above:  Sea surface temperature anomalies, October 2010.  The areas with water temperatures that are the most elevated above 1961-1990  levels are in red.  A plus sign in any grid box indicates that the temperature anomaly in that area in October was the highest since the dataset began in January 1850. Similarly a minus sign indicates the lowest SST  anomaly since 1850. White areas represent land and areas where there no SST observations were made. Source: UK Met Office's Hadley Centre.

As the map below from the National Oceanic and Atmospheric Administration (NOAA) indicates, the high sea surface temperatures in October were preceded from January through September 2010 by temperatures that were well above the long term (1971-2000) average for the region.  Furthermore, according to NOAA, the surface temperatures globally for the January-September period were the second warmest on record (tied with 1998), with 2007 in first place (see NOAA: Year-to-Date Global Temperature Ties for Warmest on Record, press release from NOAA, 15 October 2010).

Global surface temperature anomalies, January through September 2010.  Source: NOAA.

Above: Global surface temperature anomalies, January-September 2010.  Source: NOAA.

Sea Ice Impacts

One important consequence of the elevated temperatures around southern Greenland is illustrated in the figure below, showing sea ice extent in the Arctic on 5 November 2010.  Sea ice is shown in white, while the orange lines show the median ice extent during 1979-2000 period.  In addition to reduced sea ice extent on the East side of Greenland in the Denmark strait, sea ice extent is well below normal to the West of Greenland in Baffin Bay; and further West in Foxe Basin (on the West side of Baffin Island).  Declining Arctic sea ice has profound implications for the Arctic, the Northern Hemisphere and the entire planet.  See Arctic Sea Ice Decline and its Impacts: Online Resources

Arctic sea ice extent, 5 November 2010. Source: National Snow and Ice Data Center.

Above: Arctic sea ice extent, 5 November 2010. Source: National Snow and Ice Data Center.

For Greenland's Ice Cap, Record Ice Loss

Also very important are the impacts of the warmer temperatures on Greenland's massive ice cap.  In the annual "Arctic Report Card" issued by the National Oceanic and Atmospheric Administration (NOAA) on 21 October 2010 (see Scientists Report that as Arctic Sea Ice Declines, Weather Impacts Spread into Northern Mid-Latitudes, 21 October 2010), researchers summarized in its Greenland section the extraordinary changes occurring there as result of rising air and sea temperatures:

"Greenland climate in 2010 is marked by record-setting high air temperatures, ice loss by melting, and marine-terminating glacier area loss. Summer seasonal average (June-August) air temperatures around Greenland were 0.6 to 2.4°C above the 1971-2000 baseline and were highest in the west. A combination of a warm and dry 2009-2010 winter and the very warm summer resulted in the highest melt rate since at least 1958 and an area and duration of ice sheet melting that was above any previous year on record since at least 1978. The largest recorded glacier area loss observed in Greenland occurred this summer at Petermann Glacier, where 290 km2 of ice broke away. The rate of area loss in marine-terminating glaciers this year (419 km2) was 3.4 times that of the previous 8 years, when regular observations are available. There is now clear evidence that the ice area loss rate of the past decade (averaging 120 km2/year) is greater than loss rates pre-2000."

In a teleconference on 21 October 2010, Jason Box, a glaciologist with the Byrd Polar Research Center at The Ohio State University (Columbus, Ohio), said that the developments would compel researchers once again to increase their estimates of the likely rate of future sea level rise. The melting of ice from Greenland is a major contributor to rising global sea levels.  See NASA's Why Does the Greenland Ice Sheet Matter, part of a larger piece on Greenland's Ice Island Alarm (August 28, 2007); and How do We Know? Greenland's Melting Ice Sheet, a video (dated 22 September 2010) from Climate Central.

Just two days after NOAA released the Arctic report card, scientists reported in Geophysical Research Letters (Cryo‐hydrologic warming: A potential mechanism for rapid thermal response of ice sheets, 23 October 2010) that melt water flowing over and through the ice sheet can warm and further melt the ice faster than earlier expected.  The researchers reported that such warming from melt water is "already occurring along the west coast of Greenland." See Water flowing through ice sheets accelerates warming, could speed up ice flow, press release (3 November 2010) from University of Colorado at Boulder. 

Standing melt water in Greenland crevasses can carry warmth to the ice sheet's interior, accelerating the thermal response of the ice sheet to climate change.  Source: Konrad Steffen, CIRES

Above: "Standing melt water in Greenland crevasses can carry warmth to the ice sheet's interior, accelerating the thermal response of the ice sheet to climate change."  Source: Konrad Steffen, Cooperative Institute for Research in Environmental Sciences. 

Online Resources:

North Atlantic Ocean Temperatures Way Above Normal (October 2010).  From NOAA's Environmental Visualization Laboratory, circa 5 November 2010.

Water flowing through ice sheets accelerates warming, could speed up ice flow.  Press release (3 November 2010) from University of Colorado at Boulder.  Discusses findings of Cryo‐hydrologic warming: A potential mechanism for rapid thermal response of ice sheets, by Thomas Phillips, Harihar Rajaram, and Konrad Steffen.  Published in Geophysical Research Letters, 23 October 2010

Greenland's Ice Island Alarm.  Feature article (August 28, 2007) from NASA.

Climate Central:

WWF Climate Change Blog

Share this