Circular CAR Modeling of Vector Fields

As hurricanes approach landfall, there are several hazards for which coastal populations must be prepared. Damaging winds, torrential rains, and tornadoes play havoc with both the coast and inland areas; but, the biggest seaside menace to life and property is the storm surge. Wind fields are used as the primary forcing for the numerical forecasts of the coastal ocean response to hurricane force winds such as the height of the storm surge and the degree of coastal flooding. Unfortunately, developments in deterministic modeling of these forcings have been hindered by extreme computational expenses. In this paper, we present a multivariate spatial model for vector fields, that we apply to hurricane forcing winds. More specifically, a circular conditional autoregressive (CCAR) representation of the vector direction, and a spatial conditional model for the ∗D. Modlin is a Statistics PhD student at North Carolina State University (NCSU). Email: [email protected]. M. Fuentes is a Professor of Statistics at NCSU. Tel: (919) 515-1921, Fax: (919) 515-1169, Email: [email protected]. B. Reich is an Assistant Professor of Statistics at NCSU. The authors thank the National Science Foundation (Fuentes DMS-0706731, DMS-0353029), the Environmental Protection Agency (Fuentes, R833863), and National Institutes of Health (Fuentes, 5R01ES014843-02) for partial support of this work. The authors would also like to that Sujit Ghosh, Professor of Statistics at NCSU, for his input and conversation.