A Numerical Study of the Variability and the Separation of the Gulf Stream, Induced by Surface Atmospheric Forcing and Lateral Boundary Flows
A primitive equation model is used to study the effects of surface and lateral forcing on the variability and the climatology of the Gulf Stream system. The model is an eddy-resolving, coastal ocean model that includes thermohaline dynamics and a second-order turbulence closure scheme to provide ver...
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1992
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ftolddominionuni:oai:digitalcommons.odu.edu:ccpo_pubs-1130 2023-05-15T17:36:36+02:00 A Numerical Study of the Variability and the Separation of the Gulf Stream, Induced by Surface Atmospheric Forcing and Lateral Boundary Flows Ezer, Tal Mellor, George L. 1992-01-01T08:00:00Z application/pdf https://digitalcommons.odu.edu/ccpo_pubs/125 https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1130&context=ccpo_pubs unknown ODU Digital Commons https://digitalcommons.odu.edu/ccpo_pubs/125 https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1130&context=ccpo_pubs CCPO Publications COADS Florida current Gulf Stream 3-Dimensional simulation Hudson-Raritan Estuary Lateral Boundary Flows North Atlantic Delaware Bay River system Seasonal variability Wind strees Meteorology Oceanography article 1992 ftolddominionuni 2021-03-02T18:08:41Z A primitive equation model is used to study the effects of surface and lateral forcing on the variability and the climatology of the Gulf Stream system. The model is an eddy-resolving, coastal ocean model that includes thermohaline dynamics and a second-order turbulence closure scheme to provide vertical mixing. The surface forcing consists of wind stress and heat fluxes obtained from the Comprehensive Ocean-Atmosphere Data Set (COADS). Sensitivity studies are performed by driving the model with different forcing (e.g., annual versus zero surface forcing or monthly versus annual forcing). The model climatology, obtained from a five-year simulation of each case, is then compared to observed climatologies obtained from satellite-derived SST and hydrocast data. The experiments in which surface heat flux and wind stress were neglected show less realistic Gulf Stream separation and variability, compared with experiments in which annual or seasonal forcing are used. A similar unrealistic Gulf Stream separation is also obtained when the slope-water inflow at the northeast boundary is neglected. The experiments suggest that maintaining the density structure and the concomitant geostrophic flow in the northern recirculation gyre plays an important role in the separation of the Gulf Stream. The maintenance of the recirculation gyre is affected by heat transfer, wind stress, and slope-water inflow. The heat transfer involves several processes; lateral eddy transfer, surface heat flux, and vertical mixing. Further improvement of the Gulf Stream separation and climatology are obtained when seasonal changes in the lateral temperature and salinity boundary conditions are included. The seasonal climatology of the model calculations compare reasonably well with the observed climatology. Although total transports on open boundaries are maintained at climatological values, there are, nevertheless, large seasonal and spatial variations of Gulf Stream transport between Cape Hatteras and 62 degreesW. These changes are accompanied by transport changes in the northern recirculation gyre Article in Journal/Newspaper North Atlantic Old Dominion University: ODU Digital Commons Bay River ENVELOPE(-81.662,-81.662,78.882,78.882) Hudson |
institution |
Open Polar |
collection |
Old Dominion University: ODU Digital Commons |
op_collection_id |
ftolddominionuni |
language |
unknown |
topic |
COADS Florida current Gulf Stream 3-Dimensional simulation Hudson-Raritan Estuary Lateral Boundary Flows North Atlantic Delaware Bay River system Seasonal variability Wind strees Meteorology Oceanography |
spellingShingle |
COADS Florida current Gulf Stream 3-Dimensional simulation Hudson-Raritan Estuary Lateral Boundary Flows North Atlantic Delaware Bay River system Seasonal variability Wind strees Meteorology Oceanography Ezer, Tal Mellor, George L. A Numerical Study of the Variability and the Separation of the Gulf Stream, Induced by Surface Atmospheric Forcing and Lateral Boundary Flows |
topic_facet |
COADS Florida current Gulf Stream 3-Dimensional simulation Hudson-Raritan Estuary Lateral Boundary Flows North Atlantic Delaware Bay River system Seasonal variability Wind strees Meteorology Oceanography |
description |
A primitive equation model is used to study the effects of surface and lateral forcing on the variability and the climatology of the Gulf Stream system. The model is an eddy-resolving, coastal ocean model that includes thermohaline dynamics and a second-order turbulence closure scheme to provide vertical mixing. The surface forcing consists of wind stress and heat fluxes obtained from the Comprehensive Ocean-Atmosphere Data Set (COADS). Sensitivity studies are performed by driving the model with different forcing (e.g., annual versus zero surface forcing or monthly versus annual forcing). The model climatology, obtained from a five-year simulation of each case, is then compared to observed climatologies obtained from satellite-derived SST and hydrocast data. The experiments in which surface heat flux and wind stress were neglected show less realistic Gulf Stream separation and variability, compared with experiments in which annual or seasonal forcing are used. A similar unrealistic Gulf Stream separation is also obtained when the slope-water inflow at the northeast boundary is neglected. The experiments suggest that maintaining the density structure and the concomitant geostrophic flow in the northern recirculation gyre plays an important role in the separation of the Gulf Stream. The maintenance of the recirculation gyre is affected by heat transfer, wind stress, and slope-water inflow. The heat transfer involves several processes; lateral eddy transfer, surface heat flux, and vertical mixing. Further improvement of the Gulf Stream separation and climatology are obtained when seasonal changes in the lateral temperature and salinity boundary conditions are included. The seasonal climatology of the model calculations compare reasonably well with the observed climatology. Although total transports on open boundaries are maintained at climatological values, there are, nevertheless, large seasonal and spatial variations of Gulf Stream transport between Cape Hatteras and 62 degreesW. These changes are accompanied by transport changes in the northern recirculation gyre |
format |
Article in Journal/Newspaper |
author |
Ezer, Tal Mellor, George L. |
author_facet |
Ezer, Tal Mellor, George L. |
author_sort |
Ezer, Tal |
title |
A Numerical Study of the Variability and the Separation of the Gulf Stream, Induced by Surface Atmospheric Forcing and Lateral Boundary Flows |
title_short |
A Numerical Study of the Variability and the Separation of the Gulf Stream, Induced by Surface Atmospheric Forcing and Lateral Boundary Flows |
title_full |
A Numerical Study of the Variability and the Separation of the Gulf Stream, Induced by Surface Atmospheric Forcing and Lateral Boundary Flows |
title_fullStr |
A Numerical Study of the Variability and the Separation of the Gulf Stream, Induced by Surface Atmospheric Forcing and Lateral Boundary Flows |
title_full_unstemmed |
A Numerical Study of the Variability and the Separation of the Gulf Stream, Induced by Surface Atmospheric Forcing and Lateral Boundary Flows |
title_sort |
numerical study of the variability and the separation of the gulf stream, induced by surface atmospheric forcing and lateral boundary flows |
publisher |
ODU Digital Commons |
publishDate |
1992 |
url |
https://digitalcommons.odu.edu/ccpo_pubs/125 https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1130&context=ccpo_pubs |
long_lat |
ENVELOPE(-81.662,-81.662,78.882,78.882) |
geographic |
Bay River Hudson |
geographic_facet |
Bay River Hudson |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
CCPO Publications |
op_relation |
https://digitalcommons.odu.edu/ccpo_pubs/125 https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1130&context=ccpo_pubs |
_version_ |
1766136139514642432 |