By using the reanalysis data, the impact of oceanic eddies and frontal wave on Kuroshio front to the east of Taiwan (KFETW) is studied. The result indicates that cold eddies (warm eddies) corresponding to the firs...By using the reanalysis data, the impact of oceanic eddies and frontal wave on Kuroshio front to the east of Taiwan (KFETW) is studied. The result indicates that cold eddies (warm eddies) corresponding to the first baroclinic mode of Rossby wave can weaken (strengthen) the strength of the KFETW and narrow (widen) the width of this front. A frontal wave of the KFETW during January to February in 1991 is detected from the reanalysis data. And the trough (crest) of the frontal wave may weaken (strengthen) the strength of the KFETW and narrow (widen) the width and thickness of this front. It is found through the diagnostic analysis of the energy source of the frontal wave that the contribution of barotropic instability or that of baroclinic instability is more than that of Ketvin-Helmholtz (K-H) instability by 1 - 2 order of magnitude, and the contribution of the baroclinic instability is 5 times than that of the barotropic instability, thereby the frontal wave is basically driven by the baroclinic instability.展开更多
Using the Community Earth System Model framework, the authors build a very-high-resolution quasi-global coupled model by coupling an eddy-resolving quasi-global ocean model with a high-resolution atmospheric model. Th...Using the Community Earth System Model framework, the authors build a very-high-resolution quasi-global coupled model by coupling an eddy-resolving quasi-global ocean model with a high-resolution atmospheric model. The model is successfully run for six years under present climate conditions, and the simulations are evaluated against observational and reanalysis data.The model is capable of simulating large-scale oceanic and atmospheric circulation patterns, sea surface temperature(SST) fronts, oceanic eddy kinetic energy, and fine-scale structures of surface winds. The ocean mesoscale structure–induced air–sea interaction characteristics are explored in detail. The model can effectively reproduce positive correlations between SST and surface wind stress induced by mesoscale structures through comparison with observations. The positive correlation is particularly significant over regions with strong oceanic fronts and eddies.However, the responses of wind stress to eddy-induced SST are weaker in the simulation than in the observations, although different magnitudes exist in different areas. Associated with weak wind responses, surface sensible heat flux responses to eddy-induced SST are underestimated slightly, while surface latent heat flux responses are overestimated because of the drier atmospheric boundary layers in the model. Both momentum mixing and pressure adjustment mechanisms play important roles in surface wind changes over oceanic fronts and eddies in the high-resolution model.展开更多
文摘By using the reanalysis data, the impact of oceanic eddies and frontal wave on Kuroshio front to the east of Taiwan (KFETW) is studied. The result indicates that cold eddies (warm eddies) corresponding to the first baroclinic mode of Rossby wave can weaken (strengthen) the strength of the KFETW and narrow (widen) the width of this front. A frontal wave of the KFETW during January to February in 1991 is detected from the reanalysis data. And the trough (crest) of the frontal wave may weaken (strengthen) the strength of the KFETW and narrow (widen) the width and thickness of this front. It is found through the diagnostic analysis of the energy source of the frontal wave that the contribution of barotropic instability or that of baroclinic instability is more than that of Ketvin-Helmholtz (K-H) instability by 1 - 2 order of magnitude, and the contribution of the baroclinic instability is 5 times than that of the barotropic instability, thereby the frontal wave is basically driven by the baroclinic instability.
基金supported by the National Key R&D Program for Developing Basic Sciences [grant numbers2016YFC1401401 and 2016YFC1401601]the National Natural Science Foundation of China [grant numbers41376026 and 41576025]
文摘Using the Community Earth System Model framework, the authors build a very-high-resolution quasi-global coupled model by coupling an eddy-resolving quasi-global ocean model with a high-resolution atmospheric model. The model is successfully run for six years under present climate conditions, and the simulations are evaluated against observational and reanalysis data.The model is capable of simulating large-scale oceanic and atmospheric circulation patterns, sea surface temperature(SST) fronts, oceanic eddy kinetic energy, and fine-scale structures of surface winds. The ocean mesoscale structure–induced air–sea interaction characteristics are explored in detail. The model can effectively reproduce positive correlations between SST and surface wind stress induced by mesoscale structures through comparison with observations. The positive correlation is particularly significant over regions with strong oceanic fronts and eddies.However, the responses of wind stress to eddy-induced SST are weaker in the simulation than in the observations, although different magnitudes exist in different areas. Associated with weak wind responses, surface sensible heat flux responses to eddy-induced SST are underestimated slightly, while surface latent heat flux responses are overestimated because of the drier atmospheric boundary layers in the model. Both momentum mixing and pressure adjustment mechanisms play important roles in surface wind changes over oceanic fronts and eddies in the high-resolution model.