摘要
Significant increases in precipitation intensity, as a result of increases of heavy precipitation and/or decreases of light precipitation have been observed over widespread regions of the globe.Global wanning and effects of anthropogenic aerosols have been proposed as possible causes of these changes.In this work we identify the primary cause of the increases in precipitation intensity by contrasting observed characteristics of precipitation in the tropical 10°S-10°N oceanic region to those at higher latitudes (5°N-20°N, 20°N-45°N land area) in the Northern Hemisphere (NH) for 1979-2007, and a polluted region in eastern China (1955-2011).Significant increases in heavy precipitation and/or decreases in light precipitation with net increases in precipitation intensity are found in all regions examined, while amounts of total precipitation show relative small or negligible changes.Characteristics of these changes suggest that global warming rather than aerosol effects is the primary cause of the changes.