Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Climatology of the Middle Atlantic Bight Shelfbreak Front
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A Climatology of the Middle Atlantic Bight Shelfbreak Front
Author: Christopher Anthony LinderPublisher:
ISBN:
Category : Climatology
Languages : en
Pages : 96
Book Description
Description of the shelfbreak front in the Middle Atlantic Bight is hampered by the extreme variability of the front. In order to gain more insight into the mean frontal structure and associated baroclinic jet, historical data is used to produce two dimensional climatological fields of temperature and salinity for the region south of Nantucket shoals. Associated cross-shelf fields of density, geostrophic velocity, relative vorticity, and shallow water potential vorticity have also been computed. Historical data from a quality-controlled database (HydroBase) in the region 69-72°W, 39.5-41°N is included. Cross-shelf sections are obtained by averaging the data in nine depth bins with an average cross-shelf spacing of 10 km but an increased resolution of 4 km near the shelfbreak. The vertical averaging interval was 10 m over the shelf and upper slope waters, increasing to 50 m in the deep slope waters. The data were averaged in bimonthly periods to study seasonal trends. For inter-regional comparison, similar analyses were performed for the south flank of Georges Bank and the shelf off New Jersey. The climatological temperature and salinity are consistent with previous descriptions of the frontal hydrography (e.g. Wright [1976], Beardsley and Flagg [1976], and Flagg [1987]). Most importantly, features such as the "cold pool", the upper slope pycnostad, and the frontal boundary are well resolved when compared with synoptic sections. The temperature contrast across the front varies seasonally between 2-6°C near the surface and at depths of 45-65 m. The salinity contrast is 1.5-2 PSS, with little seasonal variation. The resulting cross-frontal near surface density gradients are strongest during the winter and weakest during the summer, when the seasonal thermocline is established. The crossfrontal density gradients are stronger near the bottom outcrop of the front, consistent with previous modeling studies [Gawarkiewicz and Chapman, 1992]. Despite the inherent smearing of frontal gradients incurred by averaging over large temporal and spatial scales, the geostrophic velocity field shows a strong (20-30 cm s-1) baroclinic jet associated with the cross-frontal density gradients. The core of the jet, having a width of 15-20 km, is located between the 100-120 m isobaths. The core of the jet is well shoreward of the surface expression of the front, resulting from strong density gradients at the foot of the front. The horizontal velocity shear on the cyclonic, offshore edge of the front is roughly 0.2-0.4 * 10-4 s-1, with shears on the anticyclonic, offshore edge of the jet being half as large. The potential vorticity structure is drastically affected by the seasonal pycnocline during the summer but remains relatively uniform during the winter months. Comparisons of the mean fields from Georges Bank, Nantucket Shoals, and New Jersey show that the foot of the front shoals as the flow progresses to the southwest. The seasonal migration of the frontal boundary experiences a phase shift consistent with an alongshelf propagation of minimum salinities to the southwest. Finally, transport calculations for the flow over the outer shelf and slope give values in the range of 0.1-0.6 Sv to the west. This is comparable to the estimated transport shoreward of the 100 m isobath of 0.38 Sv [Beardsley et al., 1985], which suggests that the shelfbreak frontal jet may be an extremely important element in the alongshelf transport of fresh water in this region.
Quantifying Ocean Thermal Variability in the Middle Atlantic Bight
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 3
Book Description
As part of the preparations for the Capturing Uncertainty Initiative at ONR, various measures of ocean thermal variability in the vicinity of the shelfbreak front in the Middle Atlantic Bight were calculated. The primary data source was the ONR Shelfbreak PRIMER experiment. Some of the results of thermal variability were contrasted with other sources of variability, including a historical climatology and model results.
Summarization and Interpretation of Historical, Physical, Oceanographic, and Meteorological Information for the Mid-Atlantic Region
Author: Robert G. WilliamsPublisher:
ISBN:
Category : Meteorology
Languages : en
Pages : 318
Book Description
A Compilation and Description of Hydrographic Transects of the Mid-Atlantic Bight Shelf-break Front
Author: Vincent D. LynePublisher:
ISBN:
Category : Continental shelf
Languages : en
Pages : 290
Book Description
Dynamics and Short Term Variability of the Middle Atlantic Bight Shelfbreak Front
Author: Derek Maxwell BurragePublisher:
ISBN:
Category : Continental shelf
Languages : en
Pages : 770
Book Description
Seasonal Characteristics of Bottom Boundary Layer Detachment at the Shelfbreak Front in the Middle Atlantic Bight
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 10
Book Description
The seasonality of various characteristics of the detached bottom boundary layer of the Middle Atlantic Bight shelfbreak front is examined using a collection of high resolution transects across the front. The analysis follows previous methodology in which accumulated temperature change along isopycnals within the front is used to infer the location of the detached layer. The seasonal mean isopycnal at which detachment occurs (approximately 26.0 kg cu.m) is fairly constant throughout the year. However, the vertical scale of the detached layer varies significantly with season, extending 60-80 m above the bottom in winter and spring, but only 20-40 m above the bottom in summer. The vertical scale is controlled by the strength and depth of the seasonal pycnocline. The observations suggest that the detached layer is capable of extending into the euphotic zone during winter and spring. INDEX TERMS: 4528 Oceanography: Physical: Fronts and jets; 4211 Oceanography: General: Benthic boundary layers; 4219 Oceanography: General: Continental shelf processes; 4279 Oceanography: General: Upwelling and convergences.
Wave Climate Model of the Mid-Atlantic Shelf and Shoreline (Virginia Sea)
Author: Victor GoldsmithPublisher:
ISBN:
Category : Continental shelf
Languages : en
Pages : 204
Book Description
Tracings: 91.63.05.
Oceanographic processes linking nearshore, continental shelf, and shelf break
Author: Kuoping ChiangPublisher: Frontiers Media SA
ISBN: 2832515401
Category : Science
Languages : en
Pages : 534
Book Description
The Global Coastal Ocean: Panregional syntheses and the coasts of North and South America and Asia
Author: Allan R. RobinsonPublisher: Harvard University Press
ISBN: 9780674015272
Category : Coastal ecology
Languages : en
Pages : 860
Book Description
A continuing, comprehensive and timely survey of the state of knowledge of ocean science, this distinguished series provides an overview of research frontiers as ocean science progresses. Areas covered include physical, biological, and chemical oceanography, marine geology, and geophysics and the interactions of the oceans with the atmosphere, the solid earth, and ice. Because ocean science is evolving so rapidly, straining the boundaries of traditional sub-disciplines, interdisciplinary topics have a special place in this series--including those topics related to the application of ocean science, for example, to ocean technology, marine operations, and the resources of the sea. As a treatise on advances and new developments, each topical volume starts with fundamentals and covers recent progress, so as to provide a balanced account of how oceanography is evolving. Previous volumes (1-12) in the series are now available from Harvard University Press. In the manifold, multidisciplinary efforts of.
