Climate models still struggle with medium- term climate forecasts
circulation is subjected,” explains AWI meteorologist Dörthe Handorf with respect to the special challenge presented to model makers. To test the forecast quality of the twenty-three most important climate models, the AWI scientists investigated how well these models were able to reproduce atmospheric teleconnection patterns over the past fifty years. A total of nine known circulation patterns were investigated retrospectively, four of which in special detail. The result was that the spatial distribution of atmospheric teleconnection patterns is already described very well by some models. None of the models, however, was able reliably to reproduce how strong or weak the Icelandic Low, Azores High and other meteorological centers of action were at a particular time over the last fifty years, that is, the temporal distribution patterns.
“Climate researchers throughout the world are currently working on increasing the resolution of their models and the performance of their climate computers”, says AWI researcher Dörthe Handorf in describing an obvious and important possibility of further improving the medium-term prediction quality of climate models. This enables climatic changes to be reproduced on a smaller spatial and temporal scale. “But it will not be enough to increase the pure computer power,” says the Potsdam scientist who has worked on questions of climate variability since 1997. “We must continue to work on understanding the basic processes and interactions in this complicated system called “atmosphere.” Even a high power computer reaches its limits if the mathematical equations of a climate model do not describe the real processes accurately enough.”
The Arctic plays a key role in optimizing climate models. It is one of the most important drivers of our climate and weather and is at the same time one of the regions in which the climate is currently changing the most. The “High North” is also so inhospitable that data on the Arctic is sparse. Future research work of the Potsdam scientists therefore goes in two directions. Firstly, they are developing a climate model which can resolve the small-scale, weather-determining processes in the Arctic particularly well.
The TORUS project is funded by the Federal Ministry for Education and Research (BMBF) as part of the “MiKlip — A Research Project on Decadal Climate Prediction” research program and coordinated by Dörthe Handorf. Since model improvements are only possible if comprehensive data records in high quality are available, however, a large international field campaign is planned in the Arctic for the period 2018-19. It will demand a lot from the participating scientists because part of the field campaign is to be an international Arctic drift station in which a team of researchers will drift through the Arctic Ocean with the sea ice in the Arctic winter for several months.
— Read more in Dörthe Handorf and Klaus Dethloff, “How well do state-of-the-art atmosphere-ocean general circulation models reproduce atmospheric teleconnection patterns?” Tellus 64 (29 November 2012): 19777 (doi: org/10.3402/tellusa.v64i0.19777)
