A Study of Lateral Boundary Conditions for the NRL's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS)

Abstract

Award Number: N0001403WR20321 http://www.math.nps.navy.mil/~bneta LONG-TERM GOALSOur long-term goal is to improve lateral boundary conditions in local area models. OBJECTIVESThe treatment of lateral boundaries in regional models has been a perennial problem since the early days of numerical weather prediction. In a limited-area model the lateral edges are not physical boundaries of the flow but constitute artificial constraints imposed by computational considerations. Hence they do not have a physical counterpart. We must impose conditions at these artificial boundaries in order to solve the problem in an efficient and accurate manner. We have developed high order non-reflecting boundary conditions for the dispersive Klein-Gordon equation and the linearized shallow water equations. APPROACHThe treatment of lateral boundaries in regional models has been a perennial problem since the early days of numerical weather prediction. In a limited-area model, the lateral edges are not physical boundaries of the flow but constitute artificial constraints imposed by computational considerations. Hence they do not have a physical counterpart. We must impose conditions at these artificial boundaries in order to solve the problem in an efficient and accurate manner. Several good review papers were written on the topic of both actual and artificial boundary conditions. A general discussion was presented by Turkel [24], while a review of non-reflecting boundary conditions presenting the issue in a uniform manner is that of Givoli [5]. Non-reflecting boundary 1