Home Library Strategic Plan 2003 Final Report Annex C. Graphics and Photography Source Information Figure 5-5 |
Figure 5-5: Factors affecting the predictability of precipitation in summer (June, July, and August). The influence on the predictability of precipitation is shown for (a) sea surface temperature (SST) alone and (b) both SST and land surface moisture state. The values of the predictability index were determined through an analysis of an ensemble of multi-decade atmospheric general circulation model simulations. The plotted precipitation predictability index varies from 0 to 1. Areas with values close to 1 indicate that precipitation is strongly determined by SST (and/or soil moisture), and is thus "predictable" on seasonal time scales if the SSTs (and soil moisture) themselves are predictable; whereas values close to 0 indicate that a foreknowledge of these fields may not lead to useful seasonal precipitation predictions. In the latter areas (values close to 0), nonlinear turbulent atmospheric processes would appear to dominate over SST (or soil moisture) control. Source: R.D. Koster, M. Suarez, and M. Heiser, NASA.
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