Feb 2, 2017

Detectable Anthropogenic Shift toward Heavy Precipitation over Eastern China

by
Shuangmei Ma, Tianjun Zhou, Dáithí A. Stone, Debbie Polson, Aiguo Dai, Peter A. Stott, Hans von Storch, Yun Qian, Claire Burke, Peili Wu, Liwei Zou, and Andrew Ciavarella
,
American Meteorological Society: Journal of Climate
  • States that changes in precipitation characteristics directly affect society through their impacts on drought and floods, hydro-dams, and urban drainage systems
  • States that global warming increases the water holding capacity of the atmosphere and thus the risk of heavy precipitation
  • Analyzes daily precipitation records from over 700 Chinese stations from 1956 to 2005
  • The results show a significant shift from light to heavy precipitation over eastern China
  • An optimal fingerprinting analysis of simulations from 11 climate models driven by different combinations of historical anthropogenic (greenhouse gases, aerosols, land use, and ozone) and natural (volcanic and solar) forcings indicates that anthropogenic forcing on climate, including increases in greenhouse gases (GHGs), has had a detectable contribution to the observed shift toward heavy precipitation
  • Some evidence is found that anthropogenic aerosols (AAs) partially offset the effect of the GHG forcing, resulting in a weaker shift toward heavy precipitation in simulations that include the AA forcing than in simulations with only the GHG forcing. 
  • Finds that in addition to the thermodynamic mechanism, strengthened water vapor transport from the adjacent oceans and by midlatitude westerlies, resulting mainly from GHG-induced warming, also favors heavy precipitation over eastern China
  • Concludes that GHG-induced warming is predicted to lead to an increasing shift toward heavy precipitation, leading to increased urban flooding and posing a significant challenge for mega-cities in China in the coming decades