Recent Northern Winter Climate Trends due to Ozone Changes and Increased Greenhouse Gas Forcing

摘要: Besides the increase in greenhouse gas concentrations and aerosols, considerable trends ozone concentration were recently shown, with positive values mainly upper troposphere, decreasing lower stratosphere of Northern Hemisphere middle high latitudes (WMO, 1992). The data basis consists approximately 15 to 20 years observations at various locations. changes are discussed against background observed variations temperature circulation during last decades compared results General Circulation Model (GCM) simulations effects increased concentration, additional aerosols modified profile itself. stratospheric latitude westerlies part a natural coupled mode tropospheric circulation. This has its strongest over North Atlantic westerlies, air anomalies Scandinavia Siberia. this which is associated enhanced polar intensity decades. A primary contribution intensification by low greenhouse-gas suggested. trends, when integrated into GCM, do not produce substantial supporting initial effects. It concluded that comprehensive climate model needed study future scenarios. should include atmospheric chemistry combination good representation whole stratosphere. appears most probable independent one another.