Changing westerly wind pathways bring dry polar air into western Europe
With these new results, the group also supports the hypothesis that this change in atmospheric circulation patterns over western Europe took place 170 years after the onset of cooling, as observed in the Greenland Icecores. The authors attribute this delay to the subsequent southward expansion of sea ice in the North Atlantic following the onset of cooling. This lead to a southward shift of the polar front channeling dry polar air into western Europe. "Our results also show that abrupt climate and environmental change may not be coeval on large regional scales, but can take place with substantial regional and temporal delays" explains Prof. Achim Brauer from the GFZ German Research Centre for the Geosciences.
The results of this study, which was funded by the German Research Foundation (DFG) through its Emmy-Noether Programme and the Helmholtz Climate Initiative REKLIM, do not only show unequivocally that temperature changes can have regionally different impacts, but also that the water cycle acts as amplifier of change with potentially severe effects on continental ecosystems. As such, the regional impacts of future climate changes can be largely driven by hydrological changes, not only in the monsoonal areas of the world, but also in temperate areas, such as western Europe. The results of this study contribute to the development of higher spatially resolved regional climate models, which will allow for a better prediction of the regional impacts of future climate change.
GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre