Arctic influences climate in Europe

Researchers meet for the "Arctic Climate Workshop"

Sun reflection is much higher over the ice than over the sea © Alfred Wegener Institute
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What significance does the Arctic have for the global development of the climate? How can one improve the climate forecast? Experts from Europe, USA, Canada and Russia will discuss these and many other questions at the "Arctic Climate Workshop", which will take place from 5 to 7 September 2005 at the Potsdam Research Center of the Alfred Wegener Institute for Polar and Marine Research.

The framework for the meeting is the European research project GLIMPSE (Global implications of Arctic climate processes and feedbacks) coordinated by Potsdam atmospheric researchers.

With rising temperatures, dwindling sea ice and melting glaciers, the effects of global climate change in the Arctic are particularly evident. The only a few meters thick sea ice cap at the North Pole is much more susceptible to minor changes in water or air temperature than the kilometer-thick Antarctic ice sheet. The arctic ice, which reflects up to 90 percent of the incoming sunlight like a mirror into the atmosphere, absorbs more solar energy.

The consequence would be an additional strengthening of global warming. Computer modeling should predict the extent of change. However, the high complexity of the Arctic climate system makes reliable forecasts difficult. Above all, it should be noted that in the Arctic regions natural fluctuations have played a major role in the temperature changes of recent decades.

The "Arctic Oscillation" influences the up and down temperatures in the Arctic. This is a large-scale vibration of the atmosphere characterized by opposite air pressure anomalies in the central Arctic and parts of the middle latitudes. The decades lasting vibrations are different pronounced. In the positive phase, which has prevailed since about 1970, strong westerlies in winter drive warm Atlantic air to northern Europe and Siberia. In the negative phase of the Arctic Oscillation, the cold polar air can continue to penetrate south and brings Europeans severe winters, such as last from 1940 to 1970. By including these oscillations in computer modeling, the prediction of future climate development should be significantly improved. display

The ice core analyzes so far show that climatic changes in the Arctic were faster in the past than in the Antarctic. This and the proximity to Northern and Central Europe require a deeper understanding of the mechanisms in the Arctic atmosphere - ocean - sea - ice - land, to better assess the impact of increasing greenhouse gases on our climate.

(idw - Alfred Wegener Institute for Polar and Marine Research, 05.09.2005 - DLO)