ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-6-1771-2006 Episode of unusual high solar ultraviolet radiation over central Europe due to dynamical reduced total ozone in May 2005 Stick C. 1 Krüger K. 2 3 Schade N. H. 1 Sandmann H. 1 Macke A. 3 Institut für Medizinische Klimatologie der Universität Kiel, 24118 Kiel, Germany Alfred Wegener Institut für Polar- und Meeresforschung, 14401 Potsdam, Germany Leibniz-Institut für Meereswissenschaften an der Universität Kiel, 24105 Kiel, Germany 29 05 2006 6 7 1771 1776 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/6/1771/2006/acp-6-1771-2006.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/6/1771/2006/acp-6-1771-2006.pdf

In late May 2005 unusual high levels of solar ultraviolet radiation were observed over central Europe. In Northern Germany the measured irradiance of erythemally effective radiation exceeded the climatological mean by more than about 20%. An extreme low ozone event for the season coincided with high solar elevation angles and high pressure induced clear sky conditions leading to the highest value of erythemal UV-radiation ever observed over this location in May since 1994. This hereafter called "ozone mini-hole" was caused by an elevation of tropopause height accompanied with a poleward advection of ozone-poor air from the tropics. The resultant increase in UV-radiation is of particular significance for human health. Dynamically induced low ozone episodes that happen in late spring can considerably enhance the solar UV-radiation in mid latitudes and therefore contribute to the UV-burden of people living in these regions.