Response of a global atmospheric circulation model to spatio-temporal stochastic forcing: ensemble statistics
- 1Group of Nonlinear Physics, Faculty of Physics, University of Santiago de Compostela. E-15782 Santiago de Compostela, Spain
- 2Meteorological Institute, University of Hamburg, Bundesstr. 55, D-20146 Hamburg, Germany
Abstract. The response of a simplified global atmospheric circulation model (PUMA) to spatiotemporal stochastic forcing is analyzed using the statistical measures originally developed for ensemble forecast evaluation. The nontrivial effects of time and length correlations of the stochastic forcing on the ensemble scores (e.g. spread and 'error') are studied. A maximum for these scores is observed to occur for specific values of the correlation time. The effects of multiplicative and additive contributions of the correlated noise are analyzed in terms of the noise and PUMA parameters.