Hydrology and Land Surface Studies
Changes in the variability of global land precipitation
Article first published online: 2 OCT 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 19, 16 October 2012
How to Cite
2012), Changes in the variability of global land precipitation, Geophys. Res. Lett., 39, L19402, doi:10.1029/2012GL053369., , and (
- Issue published online: 2 OCT 2012
- Article first published online: 2 OCT 2012
- Manuscript Accepted: 27 AUG 2012
- Manuscript Revised: 24 AUG 2012
- Manuscript Received: 30 JUL 2012
- p variability;
- water cycle
 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 monthlyP (1940–2009) over the global land surface using a new theoretical framework that can distinguish changes in global Pvariance between space and time. We report a near-zero temporal trend in global meanP. 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.