Antarctic Warming Up Overall According to New Study
13.01.2010 - Atmosphere & Space, Ice & Snow, Antarctic
So far, Antarctica seems to be resisting the global warming trend. However studies that reached this conclusion relied mostly upon data collected at various coastal weather stations and none from the interior of the continent, giving an incomplete picture. However by using an innovative technique, American scientists were able to construct 50-year estimates of the near-surface temperature anomalies for the entire continent, showing an overall warming trend across Antarctica.
To reconstruct these estimates, the team from the University of Washington gathered observations from manned weather stations, which extend back to 1957. Since this data is only available at stations that are mostly located on the coast, it is fairly difficult to estimate temperatures across the continent. In order to fill in the gaps in the interior of the continent, the scientists used two types of data: thermal infrared (IR) measurements from satellites and observations from ground-based automatic weather stations (AWS). By combining the thermal IR and AWS data, researchers were able to derive an Antarctic-wide temperature timeline that stretches back to 1957. Data from the two sources agreed well, and they also agree with similar work by previous researchers.
The study further shows that the warming trend observed on the Antarctic Peninsula also seems to have extended into West Antarctica, with a temperature rise of 0.1°C per decade over the past 50 years. The result doesn’t really come as a surprise and is further confirmed by measurements from nearby ice cores and boreholes.
The derived Antarctic temperature shows the warming in Antarctica to be similar to the warming that has occurred in the Southern Hemisphere over the last half century. Although overall warming can be explained by higher greenhouse gas concentrations, the pattern of change is mostly the result of the combined changes in stratospheric ozone concentrations, atmospheric circulation and sea ice extent. Furthermore, a healing hole in the ozone layer will probably lead to greater warming in East Antarctica, and possibly in West Antarctica.
