Could Disappearance of Arctic Ice signal another cold snap this winter?

“The blanket of sea ice that floats on the Arctic Ocean appears to have reached its lowest extent for the year. Arctic sea ice extent fell to 4.33 million square kilometers (1.67 million square miles) on September 9, 2011. This year's minimum was the second lowest in the satellite record, which started in 1979” (NSIDC), and is only marginally higher than the lowest extent which was recorded in 2007.

National Snow and Ice Data Centre

Scientists have established a link between the cold, snowy winters in Britain and melting sea ice in the Arctic and have warned that long periods of freezing weather are likely to become more frequent in years to come.

Physical Oceanographer Tom Rippeth, of Bangor University's School of Ocean Sceinces explains:

“Over the past few years we have seen a big decrease in the amount of sea ice floating on the Arctic Ocean. The decrease is particularly pronounced at the end of the polar summer, when the sea ice cover reaches in minimum annual level.”

“The ice plays a very important role in climate as it effectively acts as a mirror, reflecting the sun’s rays back into space. It also acts as a cap insulating the Arctic Ocean water from the atmosphere. In the absence of ice the Sun’s rays warm the water, and the warm water heats the atmosphere above.”

 “Using complex computer models scientists have found that, as the ice cap over the ocean disappeared, this allows the heat of the relatively warm seawater (0 degrees C) to escape into the much colder atmosphere above, creating an area of high pressure surrounded by clockwise-moving winds that sweep down from the Arctic over northern Europe.”

“The result here in the UK is that instead of our normal winter conditions, which are dominated by warm and wet winds blowing in off the Atlantic, we experience much colder winds coming in from the North and the East.”

“Towards the end of 2010 we saw a record low in sea ice cover for December. This provided a big heat source for the atmosphere. A consequence of this was the freezing conditions which engulfed Britain.”

“Whilst at first sight the recent spate of cold winters might be interpreted as not fitting the picture of a warming planet, they do in fact appear to be a consequence of global warming”

Arctic sea ice cover has declined throughout every season in recent years. That decline is most clearly illustrated in the decline in the end of summer sea ice minimum. Data below taken from the National Snow and Ice data Centre clearly shows this decline.

Year

Minimum Ice Extent

Date

in millions of square kilometers

in millions of square miles

2007

4.17

1.61

September 16

2008

4.55

1.76

September 18

2009

5.10

1.97

September 12

2010

4.60

1.78

September 19

2011

4.33

1.67

September 9

1979 to 2000 average

6.71

2.59

September 10

1979 to 2010 average

6.29

2.43

September 12

Publication date: 26 September 2011