New paper finds models have a high rate of ‘false alarms’ in predicting drought – - Published in Geophysical Research Letters


By: - Climate DepotSeptember 13, 2013 4:18 PM

New paper finds models have a high rate of ‘false alarms’ in predicting drought

http://hockeyschtick.blogspot.com/2013/09/new-paper-finds-models-have-high-rate.html

A paper published today in Geophysical Research Letters finds that “On average, less than 30% of the global drought onsets can be detected by climate models,” and that the models have a high rate of “false alarms.” The paper adds to the numerous peer-reviewed studies highly critical of climate models, pointing to a multitude of failings including improper simulations of temperature and precipitation, volcanic eruptions, and natural coupled ocean-atmosphere processes like El Niño and the Atlantic Multidecadal Oscillation to name a few.
Multi-model seasonal forecasting of global drought onsetXing Yuan*, Eric F. Wood

The capability of seasonal forecasting of global drought onset at local scales (1-degree) has been investigated using multiple climate models with 110 realizations. Climate models increase the global mean probability of drought onset detection from the climatology forecast by 31%-81%, but only increase equitable threat score by 21%-50% due to a high false alarm ratio. The multi-model ensemble increases the drought detectability over some tropical areas where individual models have better performance, but cannot help more over most extra-tropical regions. On average, less than 30% of the global drought onsets can be detected by climate models. The missed drought events are associated with low potential predictability and weak antecedent ENSO signal. Given the high false alarms, the reliability is very important for a skillful probabilistic drought onset forecast. This raises the question of whether seasonal forecasting of global drought onset is essentially a stochastic forecasting problem.

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