Premium
Global‐mean precipitation and black carbon in AR4 simulations
Author(s) -
Pendergrass A. G.,
Hartmann D. L.
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl050067
Subject(s) - shortwave , forcing (mathematics) , precipitation , environmental science , climatology , atmospheric sciences , radiative forcing , absorption (acoustics) , climate model , shortwave radiation , climate change , sky , meteorology , physics , radiative transfer , geology , radiation , acoustics , oceanography , quantum mechanics
How much and why precipitation changes as the climate warms is uncertain, even for the global mean. In the 21st Century of the IPCC AR4 A1b forcing scenario, global‐mean precipitation increase per degree warming varies among models by over a factor of three. Clear‐sky atmospheric shortwave absorption change explains over half of the intermodel spread ( r 2 = 0.61) in precipitation increase. Removing the part of clear‐sky atmospheric shortwave absorption change due to water vapor increase reveals that shortwave absorption forcing decreases in NCAR CCSM 3.0 but increases in GFDL CM 2.1, which we attribute to differences in black carbon forcing reported by these modeling groups. The range of applied forcing causes a range in atmospheric shortwave absorption increase, which leads to spread in precipitation increase. In contrast, in the CO 2 ‐doubling forcing scenario, clear‐sky atmospheric shortwave absorption explains an insignificant amount of spread ( r 2 = 0.04).