摘要
A three-dimensional, primitive-equation model, Blumberg's ECOMSI (Estuarine and Coastal Ocean Model with a Semi-Implicit scheme), is modified and applied to the simulation of the ocean mesoscale eddies and unstable baroclinic waves across a density front in a channel. The model uses a semi-implicit scheme to remove the most stringent Courant-Friedriechs-Levy (CFL) constraint. We have modified this model by introducing a predictor-corrector scheme to remove the inertial instability due to the Euler forward scheme in time used in the ECOMSI. Instead, the neutral amplification of the eigenvalue is obtained for the inertial oscillation. Thus,the new version of the model (called the predictorcorrector or P-C version) is able to simulate the unstable baroclinic waves and ocean mesoscale eddies in a very low viscosity environment. Meanders of a current with some similarity to mesoscale features are well reproduced. The unstable baroclinic waves are examined for flat, positive (same sense as isopycnal tilt) and negative bottoms. The growth rates with flat, gentle, medium, and steep slopes and with different wavelength (wave number) channels are discussed. A gentle positive slope significantly suppresses the meandering wave growth rate which slightly shifts to a lower wave number coml. Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA. Email: Jia. wang rsmas. miami. edu. 2. Graduate School of Environmental Earth Science, Hokkaido University, Sapporo. Japan 060. Email: mikeda eoas. hokudai. ac. jp. pared to the flat bottom. A gentle 11egative slope, however, favors the 'va\'e growth with foe maximum shifting towardsthe higher wave number. When the negative slope becomes steeper, the growth rate slgnlflcantly reduces correspondingly.
A three-dimensional, primitive-equation model, Blumberg's ECOMSI (Estuarine and Coastal Ocean Model with a Semi-Implicit scheme), is modified and applied to the simulation of the ocean mesoscale eddies and unstable baroclinic waves across a density front in a channel. The model uses a semi-implicit scheme to remove the most stringent Courant-Friedriechs-Levy (CFL) constraint. We have modified this model by introducing a predictor-corrector scheme to remove the inertial instability due to the Euler forward scheme in time used in the ECOMSI. Instead, the neutral amplification of the eigenvalue is obtained for the inertial oscillation. Thus,the new version of the model (called the predictorcorrector or P-C version) is able to simulate the unstable baroclinic waves and ocean mesoscale eddies in a very low viscosity environment. Meanders of a current with some similarity to mesoscale features are well reproduced. The unstable baroclinic waves are examined for flat, positive (same sense as isopycnal tilt) and negative bottoms. The growth rates with flat, gentle, medium, and steep slopes and with different wavelength (wave number) channels are discussed. A gentle positive slope significantly suppresses the meandering wave growth rate which slightly shifts to a lower wave number coml. Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA. Email: Jia. wang rsmas. miami. edu. 2. Graduate School of Environmental Earth Science, Hokkaido University, Sapporo. Japan 060. Email: mikeda eoas. hokudai. ac. jp. pared to the flat bottom. A gentle 11egative slope, however, favors the 'va\'e growth with foe maximum shifting towardsthe higher wave number. When the negative slope becomes steeper, the growth rate slgnlflcantly reduces correspondingly.
