How sensitive are probabilistic precipitation forecasts to the choice of ensemble generation method?

摘要

@@ 1. Intruduction As described by Wilks and Hamill 2007, errors in PQPF forecast have several sources, including initial conditions and model errors. These two particular error sources motivate two different approaches for ensemble generation: the initial and boundary condition perturbation ensemble (Toth and Kalnay 1997, Molteni et al 1996 among many others) and ensembles with different formulation of model physics or multimodel ensembles (Ebert et al. 2001, Krishnamurti et al. 1999, Park et al. 2008). The main objective of this paper is to evaluate which approach leads to a better PQPF skill over our region of interest and also to perform a comparison between perturbed initial conditions and/or perturbed physics generated ensembles with simpler and computationally cheap ensembles like the one proposed by Theis et al. 2005, which only takes into account displacement errors in the forecasted field.