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Free keywords:
anomaly pattern; circulation; geopotential height anomaly (500 hPa); middle latitude; Northern Hemisphere; volcanic eruption
Abstract:
The strengths of the polar stratospheric vortex and geopotential height anomalies of the 500 hPa layer are studied that are observed after recent violent volcanic eruptions. After all tropical eruptions the polar stratospheric vortex was intensified. The tropospheric anomaly patterns after tropical eruptions are very similar to those of winter months with a very strong stratospheric vortex, irrespective whether volcanically forced or not. Hence, if they have any effect on the wintertime tropospheric circulation, tropical eruptions seem to force a natural mode of the stratospheric winter circulation which is associated with a specific response of the tropospheric circulation with maximum amplitude over the North Altantic and adjacent continental regions. -from Authors