|
Titel |
Mean circulation in the coastal ocean off northeastern North America from a regional-scale ocean model |
VerfasserIn |
K. Chen, R. He |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1812-0784
|
Digitales Dokument |
URL |
Erschienen |
In: Ocean Science ; 11, no. 4 ; Nr. 11, no. 4 (2015-07-03), S.503-517 |
Datensatznummer |
250117261
|
Publikation (Nr.) |
copernicus.org/os-11-503-2015.pdf |
|
|
|
Zusammenfassung |
A regional-scale ocean model was used to hindcast the coastal circulation
over the Middle Atlantic Bight (MAB) and Gulf of Maine (GOM) from 2004 to
2013. The model was nested inside a data assimilative global ocean model
that provided initial and open boundary conditions. Realistic atmospheric
forcing, tides and observed river runoff were also used to drive the model.
Hindcast solutions were compared against observations, which included
coastal sea levels, satellite altimetry sea surface height, in situ
temperature and salinity measurements in the GOM, and observed mean
depth-averaged velocities. Good agreements with observations suggest that
the hindcast model is capable of capturing the major circulation variability
in the MAB and GOM. Time- and space-continuous hindcast fields were used to
depict the mean circulation, along- and cross-shelf transport and the
associated momentum balances. The hindcast confirms the presence of the
equatorward mean shelf circulation, which varies from 2.33 Sv over the
Scotian Shelf to 0.22 Sv near Cape Hatteras. Using the 200 m isobath as the
shelf/slope boundary, the mean cross-shelf transport calculations indicate
that the shelfbreak segments off the Gulf of Maine (including the southern
flank of Georges Bank and the Northeast Channel) and Cape Hatteras are the
major sites for shelf water export. The momentum analysis reveals that the
along-shelf sea level difference from Nova Scotia to Cape Hatteras is about
0.36 m. The nonlinear advection, stress, and horizontal viscosity terms all
contribute to the ageostrophic circulation in the along-isobath direction,
whereas the nonlinear advection plays a dominant role in determining the
ageostrophic current in the cross-isobath direction. |
|
|
Teil von |
|
|
|
|
|
|