CERSER Remote Sensing Research Team

Abstract

Historical Observations Of Coastal Upwellings along the Northern Beaches of the North Carolina Outer Banks

Mentor: Dr. Malcolm LeCompte
Elizabeth City State University (CERSER Lab)
1704 Weeksville Rd.
Elizabeth City, NC 27909

Observations of coastal upwellings of cold, nutrient rich, oceanic water have been reported along the New Jersey, and Long Island Bight (Neuman, 1996). These events, and their associated blooms of microorganisms can ultimately lead to reduction in dissolved oxygen due to increased rates or organic consumption and decay.The anoxic conditions thus created can be very harmful to indigenous benthic biota.

Anaylsis has indicated that the upwelling along the coast of NJ and NY and other coastal regions, wherein cold botom water displaces warmert water at the surface, occur on the down-slope side of topographic "highs" or shallow ocean bottom ridge-lines (Glenn et al. 1996). The events themselves are apparently triggered by persistent strong surface wind fields blowimg parallel to the local shore-line. In the case of the southwest to northeast running coast-line of the New Jersey shore, this is typically seen during southwest winds. In the case of the East to West oriented Long Island Bight, upwelling seems to accompany winds out of the West.

The North Carolina Bight, northward of Cape Hatteras, is oriented northwest to southeast and so, all else being equal, coastal upwellings might be expected to be driven by somewhat infrequent winds out of the southeast. If such events do occur, they might also be initiated downward of topographic highs in like manner of upwelling events seen further north. Another situational similarity between the two regions in the proximity of the northern NC Bight to the Chesapeake plume flowing out of the mouth of that bay. This is analogous to the Hudson River plume and its apparent association and interaction with coastal dynamics.

The Cerser Remote Sensing Team are examining historical AVHRR derived sea surface temperatures and archived wind data recorded at the Hatteras and Duck coastal NWS stations and obtained from the north Carolina Cimate Data Center at http://www.nc-climate.ncsu.edu. to determine the occurence seasonal upwellings events from June through Agust, of 1996 to the present and their possible correlation with topographic highs as revealed by the most current NOAA Hydrographic charts of the region.

If such a correlation can be shown to exist then it may offer a means to alert marine authorities, a marine agricultural interests and the public to the possible risk of anoxic events which might do considerable harm to the local shell or sport fishing industry.