Haidvogel, D.B.1, J. Wilkin1, K. Fennel1,
H. Arango1, P. Goodman1
1Institute of Marine and Coastal Sciences,
Rutgers University, New Brunswick, NJ 08903
The Regional Ocean Modeling System (ROMS v2.0) has been implemented
for the continental shelf and adjacent deep ocean of the U.S. east
coast
(Figure 1).
The present configuration has 10 km horizontal
resolution, 30 vertical levels, and is embedded within a North
Atlantic ROMS model forced with 3-daily average winds and
climatological buoyancy fluxes. The embedding procedure imposes
external remotely forced mesoscale and seasonal variability with few
open boundary artifacts. Coastal freshwater inputs are applied
using observed USGS river flow data. The model exhibits recognized
features of local and remotely forced circulation: namely,
wind-driven upwelling in the MAB, buoyancy-driven river plumes, low
salinity on the MAB inner shelf, retention of passive particles in
the shelf-slope front, and interactions of Gulf Stream warm rings
with the slope region.
Studies are underway in a variety of nested regions within the Northwest Atlantic, as shown in Figure 2. The scientific and technical issues addressed in these studies include a better understanding of regional processes (wind-driven upwelling and associated bio-optical response, surface boundary layer dynamics under low wind speed conditions, material transport within buoyancy-driven plumes, etc.) as well as the development of data-assimilative regional prediction systems.
As one component of these ongoing studies on the Northwest Atlantic shelves, we are developing realistic simulations of shelf circulation, mesoscale events, and interannual variability associated with major climate modes such as the North Atlantic Oscillation. This will be achieved by improving the basin-scale embedding procedure to use results from the PARADIGM modeling effort (http://www.gso.uri.edu/paradigm/), and the retrospective North Atlantic eddy-resolving models of the Mercator (www.mercator.com.fr) and HYCOM (hycom.rsmas.miami.edu) groups that assimilate satellite altimetry, sea surface temperature, and Argo float profiles. This will impose observed weekly to interannual time scale variability (predominantly from altimetry) on the physical circulation.
Figure 1. Simulated temperature at 100 meters for 16 September 1993
obtained from ROMS v2.0. Inset shows surface salinity and velocity
in the MAB-SAB. Gray line defines the open boundary of the inner
domain at which the embedding conditions are applied with negligible
apparent discontinuity.
Figure 2. Nested domains currently in use or proposed within the
Northwest Atlantic: (1) the Northeast North Atlantic domain (see
also
Fig. 1),
(2) the Northeast Observing System, (3) the Coupled
Boundary Layer Air-Sea Transfer domain, (4) the Lagrangian Transport
and Transformation Experiment, (5) the NY/NJ Bight domain, and (6)
the region of the proposed Caribbean Sea prediction system.
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