Research funded by CPO’s Climate Variability and Predictability (CVP) program has been accepted for publication in the Journal of Climate.
In this paper, authors Richard Seager (Lamont-Doherty Earth Observatory, Columbia University) and Martin Hoerling (NOAA ESRL) examine the causes of North American drought, investigate the predictability of drought, and explore the contribution of climate disturbances to drought.
Atmospheric models were forced using idealized and observed SST values to determine the contribution of tropical SST anomalies to precipitation and soil moisture as opposed to the contribution of atmospheric variability and other factors.
The authors find that up to 40 percent of the variability of annual mean precipitation in the North American south, southwest, and southern Great Plains can be explained by ocean forcing, and conclude that sea surface temperature can nudge the atmosphere into conditions, subsequently exacerbated or moderated by atmospheric variability, that can lead to drought.
The authors also find that the general warming trend over the United States, particularly in the southwest, may lead to a more rapid onset, and delayed resolution, of drought conditions in the future.
This paper is published in the June 2014 issue, and is part of a special collection on Global Drought Information System Worldwide. To view the article online, visit: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-13-00329.1