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Changes in the variability of global land precipitation
Author(s) -
Sun Fubao,
Roderick Michael L.,
Farquhar Graham D.
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 - 10.1029/2012gl053369
Subject(s) - precipitation , environmental science , climatology , aerosol , atmospheric sciences , global warming , global change , redistribution (election) , general circulation model , variance (accounting) , climate change , meteorology , geography , geology , oceanography , accounting , politics , political science , law , business
In our warming climate there is a general expectation that the variability of precipitation ( P ) will increase at daily, monthly and inter‐annual timescales. Here we analyse observations of monthly P (1940–2009) over the global land surface using a new theoretical framework that can distinguish changes in global P variance between space and time. We report a near‐zero temporal trend in global mean P. Unexpectedly we found a reduction in global land P variance over space and time that was due to a redistribution, where, on average, the dry became wetter while wet became drier. Changes in the P variance were not related to variations in temperature. Instead, the largest changes in P variance were generally found in regions having the largest aerosol emissions. Our results combined with recent modelling studies lead us to speculate that aerosol loading has played a key role in changing the variability of P.