As a crucial component of the Earth system,the ocean significantly impacts the climate due to its vast heat capacity,intricate multi-scale circulation,and considerable carbon storage capability.The ocean general circu...As a crucial component of the Earth system,the ocean significantly impacts the climate due to its vast heat capacity,intricate multi-scale circulation,and considerable carbon storage capability.The ocean general circulation model(OGCM)is a numerical tool designed to solve the governing equations of oceanic fluid and thermal dynamics.It can simulate oceanic circulations and physical states,facilitating marine environmental forecasts and climate projections.展开更多
A five-level oceanic primitive equation model has been developed. This model is integrated numerically with annual mean wind stress and heat flux at sea surface for 30 a. The ocean circulations tend to quasi-stability...A five-level oceanic primitive equation model has been developed. This model is integrated numerically with annual mean wind stress and heat flux at sea surface for 30 a. The ocean circulations tend to quasi-stability. The simulated results show that the computed annual mean currents and sea surface temperature agree well with the observations.展开更多
The feedback induced by mesoscale wind stress-SST coupling to the ocean in the western coast of South America was studied using the Regional Ocean Modeling System(ROMS).To represent the feedback,an empirical mesoscale...The feedback induced by mesoscale wind stress-SST coupling to the ocean in the western coast of South America was studied using the Regional Ocean Modeling System(ROMS).To represent the feedback,an empirical mesoscale wind stress perturbation model was constructed from satellite observations,and was incorporated into the ocean model.Comparing two experiments with and without the mesoscale wind stress-SST coupling,it was found that SST in the mesoscale coupling experiment was reduced in the western coast of South America,with the maximum values of 0.5℃in the Peru Sea and 0.7℃in the Chile Sea.A mixed layer heat budget analysis indicates that horizontal advection is the main term that explains the reduction in SST.Specifically,the feedback induced by mesoscale wind stress-SST coupling to the ocean can enhance vertical velocity in the nearshore area through the Ekman pumping,which brings subsurface cold water to the sea surface.These results indicate that the feedback due to the mesoscale wind stress-SST coupling to the ocean has the potential for reducing the warm SST bias often seen in the large-scale climate model simulations in this region.展开更多
Results of the Ocean General Circulation Model for the Earth Simulator（OFES） from January 1977 to December2006 are used to investigate mesoscale eddies near the Ryukyu Islands. The results show that：（1） Larger ed...Results of the Ocean General Circulation Model for the Earth Simulator（OFES） from January 1977 to December2006 are used to investigate mesoscale eddies near the Ryukyu Islands. The results show that：（1） Larger eddies are mainly east of Taiwan, above the Ryukyu Trench and south of the Shikoku Island. These three sea areas are all in the vicinity of the Ryukyu Current.（2） Eddies in the area of the Ryukyu Current are mainly anticyclonic, and conducive to that current. The transport of water east of the Ryukyu Islands is mainly toward the northeast.（3）The Ryukyu Current is significantly affected by the eddies. The lower the latitude, the greater these effects.However, the Kuroshio is relatively stable, and the effect of mesoscale eddies is not significant.（4） A warm eddy south of the Shikoku Island break away from the Kuroshio and move southwest, and is clearly affected by the Ryukyu Current and Kuroshio. Relationships between the mesoscale eddies, Kuroshio meanders, and Ryukyu Current are discussed.展开更多
Numerical study of ocean eddies has been carried out by using high-resolution ocean general circulation models.In order to understand ocean eddies from the large volume data produced by simulations,visualizing only ed...Numerical study of ocean eddies has been carried out by using high-resolution ocean general circulation models.In order to understand ocean eddies from the large volume data produced by simulations,visualizing only eddy distribution at each time step is insufficient;time-variations in eddy events and phenomena must also be considered.However,existing methods cannot precisely find and track eddy events such as amalgamation and bifurcation.In this study,we propose an original approach for eddy detection,tracking,and event visualization based on an eddy classification system.The proposed method detects streams and currents as well as eddies,and it classifies discovered eddies into several categories using the additional stream and current information.By tracking how the classified eddies vary over time,detecting events such as eddy amalgamation and bifurcation as well as the interaction between eddies and ocean currents becomes achievable.We adopt the proposed method for two ocean areas in which strong ocean currents exist as case studies.We visualize the detected eddies and events in a time series of images,allowing us to acquire an intuitive understanding of a region of interest concealed in a high-resolution data set.Furthermore,our proposed method succeeded in clarifying the occurrence place and seasonality of each type of eddy event.展开更多
基金supported by the National Key R&D Program for Developing Basic Sciences(2022YFC3104802)the National Natural Science Foundation of China(92358302,L2324203)+2 种基金the Project on Frontier and Interdisciplinary Research Assessment,Academic Divisions of the Chinese Academy of Sciences(XK2023DXC001)the Tai Shan Scholar Program(grant no.tstp20231237)Computing resources are financially supported by Laoshan Laboratory(no.LSKJ202300301).
文摘As a crucial component of the Earth system,the ocean significantly impacts the climate due to its vast heat capacity,intricate multi-scale circulation,and considerable carbon storage capability.The ocean general circulation model(OGCM)is a numerical tool designed to solve the governing equations of oceanic fluid and thermal dynamics.It can simulate oceanic circulations and physical states,facilitating marine environmental forecasts and climate projections.
文摘A five-level oceanic primitive equation model has been developed. This model is integrated numerically with annual mean wind stress and heat flux at sea surface for 30 a. The ocean circulations tend to quasi-stability. The simulated results show that the computed annual mean currents and sea surface temperature agree well with the observations.
基金Supported by the National Key Research and Development Program of China(No.2017YFC1404102(2017YFC1404100))the Strategic Priority Research Program of Chinese Academy of Sciences(Nos.XDA19060102,XDB40000000)+1 种基金the National Natural Science Foundation of China(Nos.41690122(41690120),41421005)the NSFC-Shandong Joint Fund for Marine Science Research Centers(No.U1406402),and the Taishan Scholarship。
文摘The feedback induced by mesoscale wind stress-SST coupling to the ocean in the western coast of South America was studied using the Regional Ocean Modeling System(ROMS).To represent the feedback,an empirical mesoscale wind stress perturbation model was constructed from satellite observations,and was incorporated into the ocean model.Comparing two experiments with and without the mesoscale wind stress-SST coupling,it was found that SST in the mesoscale coupling experiment was reduced in the western coast of South America,with the maximum values of 0.5℃in the Peru Sea and 0.7℃in the Chile Sea.A mixed layer heat budget analysis indicates that horizontal advection is the main term that explains the reduction in SST.Specifically,the feedback induced by mesoscale wind stress-SST coupling to the ocean can enhance vertical velocity in the nearshore area through the Ekman pumping,which brings subsurface cold water to the sea surface.These results indicate that the feedback due to the mesoscale wind stress-SST coupling to the ocean has the potential for reducing the warm SST bias often seen in the large-scale climate model simulations in this region.
基金The National Natural Science Foundation of China under contract No.41076003the Youth Science and Technology Foundation of East China Sea Branch,SOA under contract Nos 201314 and 201203the open fund of State Key Laboratory of Satellite Ocean Environment Dynamics under Contract No.SOED1402
文摘Results of the Ocean General Circulation Model for the Earth Simulator（OFES） from January 1977 to December2006 are used to investigate mesoscale eddies near the Ryukyu Islands. The results show that：（1） Larger eddies are mainly east of Taiwan, above the Ryukyu Trench and south of the Shikoku Island. These three sea areas are all in the vicinity of the Ryukyu Current.（2） Eddies in the area of the Ryukyu Current are mainly anticyclonic, and conducive to that current. The transport of water east of the Ryukyu Islands is mainly toward the northeast.（3）The Ryukyu Current is significantly affected by the eddies. The lower the latitude, the greater these effects.However, the Kuroshio is relatively stable, and the effect of mesoscale eddies is not significant.（4） A warm eddy south of the Shikoku Island break away from the Kuroshio and move southwest, and is clearly affected by the Ryukyu Current and Kuroshio. Relationships between the mesoscale eddies, Kuroshio meanders, and Ryukyu Current are discussed.
基金This work is supported by KAKENHI(26700010)Grant-in-Aid for Young Scientists(A)and KAKENHI(16K13885)Grant-in-Aid for Challenging Exploratory Research.JAMSTEC supported the OFES simulations that were conducted on the Earth Simulator.This paper is based on the work presented at International Conference on Computational Science 2016(ICCS2016).
文摘Numerical study of ocean eddies has been carried out by using high-resolution ocean general circulation models.In order to understand ocean eddies from the large volume data produced by simulations,visualizing only eddy distribution at each time step is insufficient;time-variations in eddy events and phenomena must also be considered.However,existing methods cannot precisely find and track eddy events such as amalgamation and bifurcation.In this study,we propose an original approach for eddy detection,tracking,and event visualization based on an eddy classification system.The proposed method detects streams and currents as well as eddies,and it classifies discovered eddies into several categories using the additional stream and current information.By tracking how the classified eddies vary over time,detecting events such as eddy amalgamation and bifurcation as well as the interaction between eddies and ocean currents becomes achievable.We adopt the proposed method for two ocean areas in which strong ocean currents exist as case studies.We visualize the detected eddies and events in a time series of images,allowing us to acquire an intuitive understanding of a region of interest concealed in a high-resolution data set.Furthermore,our proposed method succeeded in clarifying the occurrence place and seasonality of each type of eddy event.
