Atlantic sea surface temperatures affect Antarctic climate change

A new source of warming has been found for Antarctica: the North Atlantic and tropical Atlantic Ocean.

Warm waters in the Pacific have been connected to warming in Antarctica, but this is the first time that a connection with the Atlantic Ocean sea surface temperatures has been made.

"Our findings reveal a previously unknown--and surprising--force behind climate change that is occurring deep in our southern hemisphere: the Atlantic Ocean," says Xichen Li, a doctoral student in NYU's Courant Institute of Mathematical Sciences and the study's lead author. "Moreover, the study offers further confirmation that warming in one region can have far-reaching effects in another."

Global warming in recent decades has caused dramatic warming of the Antarctic Peninsula and West Antarctica. Changes in Antarctic climate have been attributed to greenhouse gas emissions and the ozone hole , sea surface temperatures in the central tropical Pacific warming (Qinghua Ding et al 2011) and the impact of El Nino.

Antarctic Peninsula: nonlinear intensification of melt unprecedented in last 1000 years

This study analysing an Antarctic Peninsula ice core from James Ross island has determined that there has been a ten fold increase in melt intensity over the last 600 years. I reported recently that the Antarctic Peninsula summer melt season prolonged by global warming according to research from the British Antarctic Survey.

"The warming has occurred in progressive phases since about AD 1460, but intensification of melt is nonlinear, and has largely occurred since the mid-twentieth century. Summer melting is now at a level that is unprecedented over the past 1,000 years. We conclude that ice on the Antarctic Peninsula is now particularly susceptible to rapid increases in melting and loss in response to relatively small increases in mean temperature." concludes the study.

The information comes from a 364 meter ice core drilled by a joint UK and French research team on James Ross Island, near the northern tip of the Antarctic Peninsula. Analysis of the ice core can reveal past temperature changes as well as revealing past extent of ice melt events.

Antarctic Peninsula summer melt season prolonged by global warming

The melt season on the Antarctic Peninsula has been getting much longer over the last 60 years, at some locations doubling in length according to the research lead by Dr Nick Barrand of the British Antarctic Survey.

Increased melting season increases the melting stress of ice shelves which hold back significant glacier discharge and sea level rise.

The Antarctic Peninsula is a mountainous region that extends north from the West Antarctic Ice Sheet towards South America. The area is warming much faster than the rest of Antarctica at around 3 times the global average, although the West Antarctic Ice Sheet (WAIS) also appears to be rapidly warming according to measurements at Byrd polar station. Temperatures have risen by up to 3 oC since the 1950s. The warming has been linked to a strengthening of local westerly winds, causing warmer air from the sea to be pushed up and over the peninsula.

• Antarctic Peninsula summer melt season extending
  
• Impact of warming on penguins and marine ecosystem
  
• Invasion of the King Crabs
  

Related: Real Climate - Antarctic Peninsula warming: natural variability or "global warming"?