Discussing the disappearance of the Arctic Sea ice

As Arctic sea ice reaches its lowest-ever recorded level in over three decades, Bangor University physical oceanographers Dr Tom Rippeth and Ben Lincoln of the School of Ocean Sciences are discussing the implications of this data with Adam Walton on Radio Wales’ Science Café programme on Tuesday 18.9.12 at 7.00 pm.

Dr Rippeth studies the world’s oceans and their effects on climate, while Ben Lincoln has just returned from the Arctic - where he's been on a research cruise on a Canadian Ice Breaker, looking at the processes responsible for the mixing of warm Pacific and Atlantic water in a region of the Arctic Ocean to the north of Canada.

 Bed Lincoln describes his experience aboard the ice breaker:

 “We joined a research cruise which has followed the same track each August for the past 10 years. This year was very different to my own experience in the Arctic in 2008. Then, I remember the overwhelming noise of the ship ploughing through the ice for most of the cruise. Of the four weeks at sea this time, we only spent a few days in the ice, and even then we had to divert from the usual course to travel to 81 degrees north to find significant ice- this is only about 600 miles from the North Pole.”

“My colleagues who have made this trip many times before were visibly shocked by the lack of ice, and one even described it as like losing an old friend. It is clear that the speed of change in the Arctic we are seeing this summer has taken even the most experienced polar scientists by surprise.”

Dr Tom Rippeth explains the significance of the decline

“Over the past few years we have seen a big decrease in the amount of sea ice floating on the Arctic Ocean during the summer. The decrease is particularly pronounced at the end of the polar summer, when the sea ice cover reaches an annual minimum. The minimum achieved this month has already smashed the previous record set in 2007, with  sea ice cover some 20% lower than in September 2007”

“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. This positive feedback results in an acceleration of the summer ice melt.”

“There is now growing evidence to suggest that there is a shift in the climate balance driven by all the extra heating in the Arctic, and that this shift may be at least in part responsible for the increased number of extreme weather events experienced in recent years. Examples of such extreme weather may include this summer, which was the wettest in over 100 years here in the UK, while at the same time many regions in the US have been struck by severe drought and heat waves.”

“Whilst the recent spate of cold weather experienced in the last few winters over central and northern Europe appears to contradict the global warming trend, there is also evidence to link these extreme weather conditions to the decline in summer sea ice cover in the Arctic.”

The team from Bangor are working with colleagues from Oxford, Southampton and Reading Universities, University College London, the National Oceanography Centre, British Antarctic Survey and the Scottish Association for Marine Science on a Natural Environment Research Council grant to improve understanding of the likely impacts of an Arctic which is free of ice in the summer.

Publication date: 18 September 2012