Tuesday, 24 January 2012
Change in An Identified Drought-Conducive Mode of Variability Under Future Climate
Hall E (New Orleans Convention Center )
A number of key mechanisms have been identified as potential drivers of recent droughts. In addition to land-surface feedbacks or persistent changes in atmospheric circulation or modes of variability, teleconnections associated with certain spatial patterns of ocean surface temperature may act as potential drought triggers. In a recent study, we identified an observational global sea surface temperature mode of natural variability that is conducive to triggering both subtropical droughts and tropical pluvials through well-known teleconnections. However, variations in the temporal features (amplitude or frequency) of this mode may occur in response to climate change, and thus affect future drought characteristics. How will this particular mode of variability evolve in the future? Will it show significant increases in intensity and/or frequency in response to continued human forcing? We will address those questions using a detection and attribution-derived technique applied on CMIP3 20th century climate runs (20CEN) with anthropogenic and natural external forcings concatenated with 21st century climate A1B projections. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.