Summer melt season is getting longer on the Antarctic Peninsula, research shows

Mar 27, 2013

New research from the Antarctic Peninsula shows that the summer melt season has been getting longer over the last 60 years. Increased summer melting has been linked to the rapid break-up of ice shelves in the area and rising sea level.

The – a mountainous region extending northwards towards South America – is warming much faster than the rest of Antarctica. Temperatures have risen by up to 3 oC since the 1950s – three times more than the global average. This is a result of a strengthening of local , causing warmer air from the sea to be pushed up and over the peninsula. In contrast to much of the rest of Antarctica, are high enough for snow to melt.

This summer melting may have important effects. Meltwater may enlarge cracks in shelves which can contribute to their retreat or collapse. As a result, the speed at which glaciers flow towards the sea will be increased. Also, melting and refreezing causes snow layers to become thinner and more dense, affecting the height of the snow surface above sea level. Scientists need to know this so they can interpret satellite data correctly.

Dr Nick Barrand, who carried out the research while working for the , led an analysis of data from 30 weather stations on the peninsula. "We found a significant increase in the length of the melting season at most of the stations with the longest temperature records" he says. "At one station the average length of the melt season almost doubled between 1948 and 2011."

To build up a more complete picture across the whole peninsula, the team (funded by the European Union's ice2sea programme) also analysed satellite data collected by an instrument called a scatterometer. Using microwave reflections from the ice sheet surface, the was able to detect the presence of meltwater. The team were able to produce maps of how the melt season varied from 1999 to 2009, and showed that several major ice shelf breakup events coincided with longer than usual melt seasons. This supports the theory that enlargement of cracks by is the main mechanism for ice shelf weakening and collapse.

The researchers also compared data from both the satellite and with the output of a state-of-the-art regional climate model.

Dr Barrand, who now works at the University of Birmingham, says, "We found that the model was very good at reproducing the pattern and timing of the melt, and changes in melting between years. This increases confidence in the use of climate models to predict future changes to snow and ice cover in the Antarctic Peninsula."

Explore further: Thousands of intense earthquakes rock Iceland

More information: Trends in Antarctic Peninsula surface melting conditions from observations and regional climate modeling will be officially published in the Journal of Geophysical Research this week.

add to favorites email to friend print save as pdf

Related Stories

Greenland and Antarctic ice sheet melting, rate unknown

Feb 16, 2009

The Greenland and Antarctica ice sheets are melting, but the amounts that will melt and the time it will take are still unknown, according to Richard Alley, Evan Pugh professor of geosciences, Penn State.

Vast Regions of West Antarctica Melted in Recent Past

May 15, 2007

A team of NASA and university scientists has found clear evidence that extensive areas of snow melted in west Antarctica in January 2005 in response to warm temperatures. This was the first widespread Antarctic ...

Annual Arctic sea ice less reflective than old ice

May 17, 2012

In the Arctic Ocean, the blanket of permanent sea ice is being progressively replaced by a transient winter cover. In recent years the extent of the northern ocean's ice cover has declined. The summer melt season is starting ...

Recommended for you

NASA sees Tropical Storm Lowell's tough south side

3 hours ago

The south side of Tropical Storm Lowell appears to be its toughest side. That is, the side with the strongest thunderstorms, according to satellite imagery from NOAA's GOES-14 and NASA-NOAA's Suomi NPP satellites.

User comments : 0