Bremerhaven, 12 January 2012. The meteorological observatory at the Antarctic Neumayer Station III is now officially considered to be a climate observation station by virtue of the fact that meteorologists of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association have been measuring the air temperature in Antarctica on a daily basis for 30 years. One of the results of the long-term research: the air at Neumayer Station has not become warmer over the past three decades.
Climate is defined by the World Meteorological Organization of the United Nations (WMO) as the mean value over a period of 30 years. The meteorological observatory at the Antarctic Neumayer Station III has now reached this annual mark. The observatory is now officially considered to be a WMO climate observation station. “In 1982 we succeeded for the first time in measuring the air temperature every day of the year. Today, 30 years later, our observatory automatically records the air temperature, air pressure, wind speed and other weather data every three hours. They are coded after each measurement and transmitted to other research stations in Antarctica as well as to the global data network of the weather services via e-mail. In this way our measurement data help, for example, to improve weather forecasts,” says meteorologist and scientific head of the observatory Dr. Gert König-Langlo.
To be able to collect reliable temperature data, the meteorologists at the Alfred Wegener Institute used a thermometer of a special kind. It consists of a temperature-sensitive platinum wire protected against solar radiation. It is installed on the observatory tower at a height of two metres, ambient air is swirled around it at every measurement and the data are read out by a computer. “We regularly check the stability of this measuring system by means of reference thermometers,” explains Gert König-Langlo.
In the course of time a meaningful data record developed in this way (see Fig. 1). “In the past 30 years it was minus 16.0 degree Celsius cold at the station on an annual average. With an average temperature of minus 14.3 degrees Celsius 1996 is regarded as the warmest year in the past three decades while the year 2000 is considered the coldest at minus 17.8 degrees Celsius,” says Gert König-Langlo.
At the same time the measurements verify that it has not become warmer at the research station on the Ekström Ice Shelf – in contrast to the Antarctic Peninsula. On the other hand, the hours of sunshine and air pressure at Neumayer Station have increased significantly (see Figs. 2 and 3). “Our weather data show that the part of the Antarctic in which our station is located is more frequently exposed to high-pressure influence. This means we have a cloud-free sky more frequently. And wherever there is no cloud cover in polar regions, heat is radiated unhindered and the lower air layers cool off,” explains Gert König-Langlo.
He adds, however, that this development is a regional change and the values measured at Neumayer Station III are by no means representative for the global climate changes. “Just in the centre of Antarctica it has not become warmer. On the Antarctic Peninsula, by contrast, the average temperature has risen by up to three degrees Celsius. We also observe a similar warming in the Arctic,” says Gert König-Langlo.
Why the temperature curve at the Neumayer Station differs so extensively from that of the research stations on the Antarctic Peninsula, he notes, is the subject of current research. “Further measurements and research efforts are necessary to clarify this situation,” explains Gert König-Langlo.
Notes for Editors:
Your contact at the Alfred Wegener Institute is Dr. Gert König-Langlo (Tel: 0471 4831-1806; E-Mail: Gert.Koenig-Langlo(at)awi.de) and in the press office Sina Löschke (Tel: 0471 4831-2008; E-Mail: Sina.Loeschke(at)awi.de).
