The wave-forcing 'Coriolis-Stokes forcing' and 'Stokes-vortex force' induced by Stokes drift affect the upper ocean jointly.To study the effect of the wave-induced Stokes drift on the dynamics of the o...The wave-forcing 'Coriolis-Stokes forcing' and 'Stokes-vortex force' induced by Stokes drift affect the upper ocean jointly.To study the effect of the wave-induced Stokes drift on the dynamics of the ocean mixed layer,a new three-dimensional(3D) numerical model is derived using the primitive basic equations and Eulerian wave averaging.The Princeton Ocean Model(POM),a 3D primitive equation ocean model is used with the upper wave-averaged basic equations.The global ocean circulation is simulated using the POM model,and the Stokes drift is evaluated based on the wave data generated by WAVEWATCH III.We compared simulations with and without the Stokes drift.The results show that the magnitude of the Stokes drift is comparable with the Eulerian mean current.Including the Stokes drift in the ocean model affects both the Eulerian current and the Lagranian drift and causes the vertical mixing coefficients to increase.展开更多
The Brazilian coast is characterized by different tidal regimes and distinct meteorological influences. The northern part has larger tidal amplitudes and is permanently affected by trade winds and tropical disturbance...The Brazilian coast is characterized by different tidal regimes and distinct meteorological influences. The northern part has larger tidal amplitudes and is permanently affected by trade winds and tropical disturbances; the southern portion has smaller tidal amplitudes and is frequently influenced by extratropical cyclone activity. Besides these aspects, many features regarding current structure and behavior are also present, such as the equatorial system of currents, the subtropical gyre and the corresponding western boundary currents, and the Brazil-Malvinas confluence region. Within this context, efforts were made to develop the BRAZCOAST system, capable of describing the processes that determine the oceanic circulation from large to coastal scales. A customized version of the Princeton Ocean Model(POM) was implemented in a basin-scale domain covering the whole of the tropical and southern Atlantic Ocean, with 0.5° spatial resolution, as well as three nested grids with(1/12)° resolution covering the different parts of the Brazilian shelf, in a one-way procedure. POM was modified to include tidal potential generator terms and a partially-clamped boundary condition for tidal elevations. The coarse grid captured large-scale features, while the nested grids detailed local circulations affected by bathymetry and coastal restrictions. An interesting aspect at the coarse grid level was the relevance of the Weddell Sea to the location of the tidal amphidromic systems.展开更多
A free surface quasi-global ocean circulation model, Princeton Ocean Model(POM), was adopted to simulate the climatological circulation. The horizontal resolution of themodel was 1/2° x 1/2° with 16 vertical...A free surface quasi-global ocean circulation model, Princeton Ocean Model(POM), was adopted to simulate the climatological circulation. The horizontal resolution of themodel was 1/2° x 1/2° with 16 vertical sigma layers. The initial temperature and salinity fieldsof the model were interpolated from the Levitus data, and the COADS (Comprehensive Ocean-AtmosphereData Set) monthly mean SST and wind fields were used as the surface forcing. The integral timelength is 6a. The main general circulation components such as the equatorial current, the equatorialundercurrent, the south and north equatorial currents, the Antarctic Circumpolar Current (ACC), theKuroshio and the Gulf Stream were well reconstructed. The volume transports of PN section and ACCa-gree well with the estimations on field survey. Up to now there is no global or quasi-globalcirculation model results u-sing POM in literature. Our results demonstrate that POM has soundability to simulate the coastal circulation as well as the general ocean circulation. And thisresult can provide open boundary conditions for fine resolution regional ocean circulation models.展开更多
In the past 20 a, the gulf-scale circulation in the Beibu Gulf has been commonly accepted to be driven by a wind stress or density gradient. However, using three sensitive experiments based on a three-dimensional baro...In the past 20 a, the gulf-scale circulation in the Beibu Gulf has been commonly accepted to be driven by a wind stress or density gradient. However, using three sensitive experiments based on a three-dimensional baroclinic model that was verified by observations, the formation mechanisms were revealed： the circula- tion in the northern Beibu Gulf was triggered by the monsoon wind throughout a year; whereas the southern gulf circulation was driven by the monsoon wind and South China Sea （SCS） circulation in winter and sum- mer, respectively. The force of heat flux and tidal harmonics had a strong effect on the circulation strength and range, as well as the local circulation structures, but these factors did not influence the major circulation structure in the Beibu Gulf. On the other hand, the Beibu Gulf Cold Water Mass （BGCWM） would disappear without the force of heat flux because the seasonal thermocline layer was generated by the input of heat so that the vertical mixing between the upper hot water and lower cold water was blocked. In addition, the wind-induced cyclonic gyre in the northern gulf was favorable to the existence of the BGCWM. However, the coverage area of the BGCWM was increased slightly without the force of the tidal harmonics. When the model was driven by the monthly averaged surface forcing, the circulation structure was changed to some extent, and the coverage area of the BGCWM almost extended outwards 100%, implying the circulation and water mass in the Beibu Gulf had strong responses to the temporal resolution of the surface forces.展开更多
Observations show that during summer especially in August, the northward expansion of the Changjiang（Yangtze） River diluted water （CRDW） is blocked in the vicinity of the Changjiang Estuary. To explain this phenom...Observations show that during summer especially in August, the northward expansion of the Changjiang（Yangtze） River diluted water （CRDW） is blocked in the vicinity of the Changjiang Estuary. To explain this phenomenon, Princeton ocean model （POM） is applied to simulate the summertime expansion pattern of CRDW. Numerical experiments show that to the north of the Changjiang Estuary, a tide-induced temperature front of a cold water centered at （34°N, I22.5°E） plays the key role in determining the expansion pattern of CRDW. This front splits the CRDW into two parts： the main part expands northeastward, and the other small part expands northwestward off the coast of Jiangsu Province, China.展开更多
With consideration of the comprehensive effects of runoff from the Yangtze River, East China Sea background circulation, and tidal currents,a regional circulation model, including the Yangtze Estuary, Hangzhou Bay, an...With consideration of the comprehensive effects of runoff from the Yangtze River, East China Sea background circulation, and tidal currents,a regional circulation model, including the Yangtze Estuary, Hangzhou Bay, and adjacent sea areas was established. The 2002/2003 El Ni^no event was chosen for study of the anomalies of circulation outside the Yangtze Estuary. The coastal and ocean current systems of the East China Sea and the current structure outside the Yangtze Estuary were accurately described. The results of vertical circulation analysis basically coincide with those of horizontal circulation analysis, showing that the circulation outside the Yangtze Estuary is mainly affected by the Taiwan warm current, runoff from the Yangtze Estuary, and the tide-induced residual current. The El Ni^no event weakens Yangtze Estuary circulation to a certain degree, and the impacts are more significant in summer than in winter. During the 2002/2003 El Ni^no event, the flux of the Taiwan warm current decreases, and the northward component of the Taiwan warm current decreases by half in February 2003 compared to the previous year. However, its path is relatively stable.展开更多
Princeton Ocean Model is used to study the response of Jervis Bay, NSW, Australia, to the local wind and remote shelf coastal trapped wave (CTW) forcings in summer seasons when the water column is stratified by the wa...Princeton Ocean Model is used to study the response of Jervis Bay, NSW, Australia, to the local wind and remote shelf coastal trapped wave (CTW) forcings in summer seasons when the water column is stratified by the water temperature.The study has revealed that the response of bay to the wind forcing is the generation of the wind driven currents and the internal Kelvin waves (IKW). However, both temperature and flow sub-inertial oscillations in the bay are weaker than those from the observations and the correlation between the modeled and observed low frequency currents is low. In response to the forcing of CTWs on the adjacent shelf, IKWs are also established in the bay and amplitudes of sub-inertial oscillations of temperature and currents agree better with the observations. It can be concluded that sub-inertial baroclinic flows in the bay is dominantly forced by remote CTW on the shelf adjacent to Jervis Bay during thermally stratified summer seasons.展开更多
基金Supported by the National Natural Science Foundation of China(No.41376028)the Open Fund of the Shandong Province Key Laboratory of Ocean Engineering,Ocean University of China(No.201362045)
文摘The wave-forcing 'Coriolis-Stokes forcing' and 'Stokes-vortex force' induced by Stokes drift affect the upper ocean jointly.To study the effect of the wave-induced Stokes drift on the dynamics of the ocean mixed layer,a new three-dimensional(3D) numerical model is derived using the primitive basic equations and Eulerian wave averaging.The Princeton Ocean Model(POM),a 3D primitive equation ocean model is used with the upper wave-averaged basic equations.The global ocean circulation is simulated using the POM model,and the Stokes drift is evaluated based on the wave data generated by WAVEWATCH III.We compared simulations with and without the Stokes drift.The results show that the magnitude of the Stokes drift is comparable with the Eulerian mean current.Including the Stokes drift in the ocean model affects both the Eulerian current and the Lagranian drift and causes the vertical mixing coefficients to increase.
基金the Brazilian agencies FAPESP (Sao Paulo State Research Agency) and CNPq (National Council for Scientific and Technological Development) for funding throughout the development of this work
文摘The Brazilian coast is characterized by different tidal regimes and distinct meteorological influences. The northern part has larger tidal amplitudes and is permanently affected by trade winds and tropical disturbances; the southern portion has smaller tidal amplitudes and is frequently influenced by extratropical cyclone activity. Besides these aspects, many features regarding current structure and behavior are also present, such as the equatorial system of currents, the subtropical gyre and the corresponding western boundary currents, and the Brazil-Malvinas confluence region. Within this context, efforts were made to develop the BRAZCOAST system, capable of describing the processes that determine the oceanic circulation from large to coastal scales. A customized version of the Princeton Ocean Model(POM) was implemented in a basin-scale domain covering the whole of the tropical and southern Atlantic Ocean, with 0.5° spatial resolution, as well as three nested grids with(1/12)° resolution covering the different parts of the Brazilian shelf, in a one-way procedure. POM was modified to include tidal potential generator terms and a partially-clamped boundary condition for tidal elevations. The coarse grid captured large-scale features, while the nested grids detailed local circulations affected by bathymetry and coastal restrictions. An interesting aspect at the coarse grid level was the relevance of the Weddell Sea to the location of the tidal amphidromic systems.
文摘A free surface quasi-global ocean circulation model, Princeton Ocean Model(POM), was adopted to simulate the climatological circulation. The horizontal resolution of themodel was 1/2° x 1/2° with 16 vertical sigma layers. The initial temperature and salinity fieldsof the model were interpolated from the Levitus data, and the COADS (Comprehensive Ocean-AtmosphereData Set) monthly mean SST and wind fields were used as the surface forcing. The integral timelength is 6a. The main general circulation components such as the equatorial current, the equatorialundercurrent, the south and north equatorial currents, the Antarctic Circumpolar Current (ACC), theKuroshio and the Gulf Stream were well reconstructed. The volume transports of PN section and ACCa-gree well with the estimations on field survey. Up to now there is no global or quasi-globalcirculation model results u-sing POM in literature. Our results demonstrate that POM has soundability to simulate the coastal circulation as well as the general ocean circulation. And thisresult can provide open boundary conditions for fine resolution regional ocean circulation models.
基金The Guangxi Natural Science Foundation under contract No.2012GXNSFEA053001the program of"The Beibu Gulf forecast circulation system construction and its application to the coastal pollution transport"
文摘In the past 20 a, the gulf-scale circulation in the Beibu Gulf has been commonly accepted to be driven by a wind stress or density gradient. However, using three sensitive experiments based on a three-dimensional baroclinic model that was verified by observations, the formation mechanisms were revealed： the circula- tion in the northern Beibu Gulf was triggered by the monsoon wind throughout a year; whereas the southern gulf circulation was driven by the monsoon wind and South China Sea （SCS） circulation in winter and sum- mer, respectively. The force of heat flux and tidal harmonics had a strong effect on the circulation strength and range, as well as the local circulation structures, but these factors did not influence the major circulation structure in the Beibu Gulf. On the other hand, the Beibu Gulf Cold Water Mass （BGCWM） would disappear without the force of heat flux because the seasonal thermocline layer was generated by the input of heat so that the vertical mixing between the upper hot water and lower cold water was blocked. In addition, the wind-induced cyclonic gyre in the northern gulf was favorable to the existence of the BGCWM. However, the coverage area of the BGCWM was increased slightly without the force of the tidal harmonics. When the model was driven by the monthly averaged surface forcing, the circulation structure was changed to some extent, and the coverage area of the BGCWM almost extended outwards 100%, implying the circulation and water mass in the Beibu Gulf had strong responses to the temporal resolution of the surface forces.
基金The National Key Basic Research Program of China under contract No.2006CB403605
文摘Observations show that during summer especially in August, the northward expansion of the Changjiang（Yangtze） River diluted water （CRDW） is blocked in the vicinity of the Changjiang Estuary. To explain this phenomenon, Princeton ocean model （POM） is applied to simulate the summertime expansion pattern of CRDW. Numerical experiments show that to the north of the Changjiang Estuary, a tide-induced temperature front of a cold water centered at （34°N, I22.5°E） plays the key role in determining the expansion pattern of CRDW. This front splits the CRDW into two parts： the main part expands northeastward, and the other small part expands northwestward off the coast of Jiangsu Province, China.
基金the National Natural Science Foundation of China(Grant No.51379003)the Fundamental Research Funds for the Central Universities(Grant No.2015B15814)the Program for New Century Excellent Talents in University(Grant No.NCET-12-0841)
文摘With consideration of the comprehensive effects of runoff from the Yangtze River, East China Sea background circulation, and tidal currents,a regional circulation model, including the Yangtze Estuary, Hangzhou Bay, and adjacent sea areas was established. The 2002/2003 El Ni^no event was chosen for study of the anomalies of circulation outside the Yangtze Estuary. The coastal and ocean current systems of the East China Sea and the current structure outside the Yangtze Estuary were accurately described. The results of vertical circulation analysis basically coincide with those of horizontal circulation analysis, showing that the circulation outside the Yangtze Estuary is mainly affected by the Taiwan warm current, runoff from the Yangtze Estuary, and the tide-induced residual current. The El Ni^no event weakens Yangtze Estuary circulation to a certain degree, and the impacts are more significant in summer than in winter. During the 2002/2003 El Ni^no event, the flux of the Taiwan warm current decreases, and the northward component of the Taiwan warm current decreases by half in February 2003 compared to the previous year. However, its path is relatively stable.
基金jointly supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA19060503,XDA11010304 and XDA13030103)National Natural Science Foundation of China (Grants Nos.41776028,41676016,41376021,and 41521005)+3 种基金the MOST of China (Grant No. 2014CB953904)Science and Technology Program of Guangzhou,China (Grant No.201607020043)supported by Science and Technology Planning Project of Guangdong Province,China (Grant No. 20150217)Funding of China Scholarship Council (Grant No. 201704910146)~~
文摘Princeton Ocean Model is used to study the response of Jervis Bay, NSW, Australia, to the local wind and remote shelf coastal trapped wave (CTW) forcings in summer seasons when the water column is stratified by the water temperature.The study has revealed that the response of bay to the wind forcing is the generation of the wind driven currents and the internal Kelvin waves (IKW). However, both temperature and flow sub-inertial oscillations in the bay are weaker than those from the observations and the correlation between the modeled and observed low frequency currents is low. In response to the forcing of CTWs on the adjacent shelf, IKWs are also established in the bay and amplitudes of sub-inertial oscillations of temperature and currents agree better with the observations. It can be concluded that sub-inertial baroclinic flows in the bay is dominantly forced by remote CTW on the shelf adjacent to Jervis Bay during thermally stratified summer seasons.
