Design of a Multiply Nested Primitive Equation Ocean Model

A new multiply nested primitive equation ocean model is presented. The model employs a two-way interactive nesting technique successfully applied for many years in the Geophysical Fluid Dynamics Laboratory‐NOAA hurricane prediction model. The formulation of the mesh nesting algorithm allows flexibility in deciding the number of meshes and the ratio of grid resolutions between adjacent meshes. Other advanced features include realistic coastline geometry and spatially variable grid spacing. The results of various idealized experiments indicate good performance of the nesting technique. The most important feature of the model is the ability to combine large-scale and regional-scale predictions. The model is tested as a general circulation model (GCM) in a 3-yr spinup experiment of the large-scale circulation in the tropical Pacific Ocean. It demonstrates skill comparable to that of other recently developed GCMs. The resulting large-scale fields are then used in the nested configuration as initial conditions for simulations of the ocean response to a westerly wind burst and a tropical cyclone. Significant improvements over a coarse, singlemesh model have been achieved in resolving finescale features of the wind-induced current and temperature fields. These results highlight the importance of model resolution for realistic simulations of mesoscale ocean variability.

[1]  G. Flierl,et al.  Isolated Eddy Models in Geophysics , 1987 .

[2]  Antonio J. Busalacchi,et al.  The roles of vertical mixing, solar radiation, and wind stress in a model simulation of the sea surface temperature seasonal cycle in the tropical Pacific Ocean , 1994 .

[3]  J. Toole,et al.  The response of the western equatorial Pacific Ocean to westerly wind bursts during November 1989 to January 1990 , 1992 .

[4]  Robert Pinkel,et al.  Diurnal cycling: observations and models of the upper-ocean response to diurnal heating, cooling, and wind mixing. Technical report , 1986 .

[5]  G. Tripoli,et al.  An Iterative Time Integration Scheme Designed to Preserve a Low-Frequency Wave , 1976 .

[6]  W. Hurlin,et al.  Simulation of the Seasonal Cycle of the Tropical Pacific Ocean , 1987 .

[7]  Y. Kurihara,et al.  A Numerical Scheme to Treat the Open Lateral Boundary of a Limited Area Model , 1983 .

[8]  S. J. Maskell,et al.  Two-Way Interactive Nesting of Primitive Equation Ocean Models with Topography , 1995 .

[9]  J. Hesthaven,et al.  Dynamical properties of vortical structures on the beta-plane , 1994, Journal of Fluid Mechanics.

[10]  C. Gordon,et al.  A model simulation of the seasonal cycle in the tropical Pacific Ocean using climatological and modeled surface forcing , 1991 .

[11]  K. Bryan.  A SCHEME FOR NUMERICAL INTEGRATION OF THE EQUATIONS OF MOTION ON AN IRREGULAR GRID FREE OF NONLINEAR INSTABILITY , 1966 .

[12]  Caskey,et al.  GENERAL CIRCULATION EXPERIMENTS WITH THE PRIMITIVE EQUATIONS I . THE BASIC EXPERIMENT , 1962 .

[13]  Yoshio Kurihara,et al.  Improvements in Tropical Cyclone Track and Intensity Forecasts Using the GFDL Initialization System , 1993 .

[14]  D. E. Harrison,et al.  Episodes of surface westerly winds as observed from islands in the western tropical Pacific , 1991 .

[15]  T. Yamagata,et al.  Unstable Air-Sea Interactions in the Tropics , 1984 .

[16]  E. Hopfinger,et al.  Vortices in Rotating Fluids , 1993 .

[17]  Da‐Lin Zhang,et al.  A two-way interactive nesting procedure with variable terrain resolution , 1986 .

[18]  M. Endoh,et al.  A free surface general circulation model for the tropical Pacific Ocean , 1992 .

[19]  Gregory J. Tripoli,et al.  Design of a Movable Nested-Mesh Primitive Equation Model , 1979 .

[20]  Richard A. Anthes,et al.  Numerical Simulations of the Ocean's Nonlinear, Baroclinic Response to Translating hurricanes , 1978 .

[21]  Peter R. Gent,et al.  A reduced gravity, primitive equation model of the upper equatorial ocean , 1989 .

[22]  Christopher L. Kerr,et al.  An Improved Numerical Scheme to Treat the Open Lateral Boundary of a Regional Model , 1989 .

[23]  W. Rossow,et al.  ISCCP Cloud Data Products , 1991 .

[24]  J. Kindle,et al.  The ocean response to operational westerly wind bursts during the 1991–1992 El Niño , 1995 .

[25]  Y. Kurihara,et al.  NUMERICAL INTEGRATION OF A NINE-LEVEL GLOBAL PRIMITIVE EQUATIONS MODEL FORMULATED BY THE BOX METHOD , 1967 .

[26]  A. Arakawa,et al.  Numerical methods used in atmospheric models , 1976 .

[27]  Yoshio Kurihara,et al.  The GFDL Hurricane Prediction System and Its Performance in the 1995 Hurricane Season , 1998 .

[28]  Ping Chen,et al.  A nested‐grid ocean model: With application to the simulation of meanders and eddies in the Norwegian Coastal Current , 1992 .

[29]  R. Seager,et al.  A model of the tropical Pacific sea surface temperature climatology , 1988 .

[30]  Michael A. Spall,et al.  A nested primitive equation model for oceanic applications , 1991 .

[31]  Bernard Kilonsky,et al.  Mean Water and Current Structure during the Hawaii-to-Tahiti Shuttle Experiment , 1984 .

[32]  P. Webster,et al.  TOGA COARE: The Coupled Ocean-Atmosphere Response Experiment. , 1992 .

[33]  Dake Chen,et al.  A Hybrid Vertical Mixing Scheme and Its Application to Tropical Ocean Models , 1994 .

[34]  J. Smagorinsky,et al.  GENERAL CIRCULATION EXPERIMENTS WITH THE PRIMITIVE EQUATIONS , 1963 .

[35]  G. Mellor.  An Equation of State for Numerical Models of Oceans and Estuaries , 1991 .

[36]  S. Levitus.  Climatological Atlas of the World Ocean , 1982 .

[37]  Kozo H. Yoshida.  A Theory of the Cromwell Current (the Equatorial Undercurrent) and of the Equatorial Upwelling , 1959 .