Localized Ensemble-Based Tangent Linear Models and Their Use in Propagating Hybrid Error Covariance Models
Sergey Frolov, Craig H Bishop
MONTHLY WEATHER REVIEW | AMER METEOROLOGICAL SOC | Published : 2016
Hybrid error covariance models that blend climatological estimates of forecast error covariances with ensemble-based, flow-dependent forecast error covariances have led to significant reductions in forecast error when employed in 4DVAR data assimilation schemes. Tangent linear models (TLMs) designed to predict the differences between perturbed and unperturbed simulations of the weather forecast are a key component of such 4DVAR schemes. However, many forecasting centers have found that TLMs and their adjoints do not scale well computationally and are difficult to create and maintain-particularly for coupled ocean-wave-ice-atmosphere models. In this paper, the authors create ensemble-based TL..View full abstract
Awarded by Office of Naval Research
This work was supported by the Office of Naval Research Award N0001412WX20323. We are grateful to Douglas Allen from NRL-DC for providing comments on the early version of this manuscript. We are grateful to Chris Snyder and two other anonymous reviewers for their insightful comments that helped to improve the quality of this manuscript.