Precipitation response to regional radiative forcing

Published

Journal Article

Precipitation shifts can have large impacts on human society and ecosystems. Many aspects of how inhomogeneous radiative forcings influence precipitation remain unclear, however. Here we investigate regional precipitation responses to various forcings imposed in different latitude bands in a climate model. We find that several regions show strong, significant responses to most forcings, but that the magnitude and even the sign depends upon the forcing location and type. Aerosol and ozone forcings typically induce larger responses than equivalent carbon dioxide (CO 2) forcing, and the influence of remote forcings often outweighs that of local forcings. Consistent with this, ozone and especially aerosols contribute greatly to precipitation changes over the Sahel and South and East Asia in historical simulations, and inclusion of aerosols greatly increases the agreement with observed trends in these areas, which cannot be attributed to either greenhouse gases or natural forcings. Estimates of precipitation responses derived from multiplying our Regional Precipitation Potentials (RPP; the response per unit forcing relationships) by historical forcings typically capture the actual response in full transient climate simulations fairly well, suggesting that these relationships may provide useful metrics. The strong sensitivity to aerosol and ozone forcing suggests that although some air quality improvements may unmask greenhouse gas-induced warming, they have large benefits for reducing regional disruption of the hydrologic cycle. © 2012 Author(s).

Full Text

Duke Authors

Cited Authors

  • Shindell, DT; Voulgarakis, A; Faluvegi, G; Milly, G

Published Date

  • November 19, 2012

Published In

Volume / Issue

  • 12 / 15

Start / End Page

  • 6969 - 6982

Electronic International Standard Serial Number (EISSN)

  • 1680-7324

International Standard Serial Number (ISSN)

  • 1680-7316

Digital Object Identifier (DOI)

  • 10.5194/acp-12-6969-2012

Citation Source

  • Scopus