A Study of Warm Core Ring - Shelf/Slope Interaction from the Oleander Project

Suny At Stony Brook, Stony Brook NY

Investigators

Abstract

0425413 Intellectual merit: The Oleander project was conceived primarily to establish a long-term monitoring of the Gulf Stream's pole ward transport of mass and heat. Since October of 1992, the container ship, the MV Oleander, has been collecting ADCP observations on an almost continuous basis as the ship makes its weekly trips between New York and Bermuda. Over the last nine years (1993-2001) a total of 554 useful shelf/slope transects have been obtained, as well as a complete analysis of detiding, which has offered new insights about the Mid-Atlantic Bight shelf/slope circulation. But, perhaps what has been even more revealing from the Oleander transects are the observations which have indicated that the warm core rings observed over the transit area have sustained much influence on the shelf/slope. Nearly one-half of the transects were influenced by strong easterly currents associated with warm core rings, suggesting that the warm core rings most likely dominate the shelf-slope water exchange. Therefore, it is timely to complete a study of the shelf/slope circulation that also considers the impact of warm core rings. In this project, researchers from the State University of New York at Stony Brooks will continue the present data analysis effort of the Oleander project, but shift the emphasis toward interpretation rather than quality assurance. Specifically, the team of scientists will combine the Oleander observations with satellite and other complimentary data, to investigate the interaction of the Gulf Stream warm core rings with the Mid-Atlantic Bight shelf and slope. Each ring-induced small-scale feature along the transit line will be isolated and their generation mechanisms examined, so that the researchers can: 1) define the velocity structures of small-scale cyclones, anticyclones, and jets (streamers and shelfbreak jet) with respect to the swirling motion of the warm rings; 2) determine whether or not there are significantly different types of ring-slope interactions in relation to the ring size, strength, and proximity to the shelfbreak; 3) determine the seasonal dependence and possible interannual variability (in relation to Gulf Stream path variations) of the ring-slope interaction. And 4) Examine the mechanisms of generation of cyclones, anticyclones, and streamers. Broader Impacts: The mean and seasonal shelf/slope currents are determined for the period of no visible influence of warm core rings. It is shown that the equatorward transport extends well beyond the shelf break and that the upper slope currents are a major source of the shelf water transport.. Since the shelf/slope currents are much more energetic during the ring period, it is likely that warm core rings may dominate the exchange between shelf and slope. At present, very little is known about the ring-slope interaction. The proposed study will shed insights about this important but long ignored process. The implication can be enormous, leading to a new understanding of the material (water, salt, carbon cycle, etc.) exchange across the continental margin. This project also includes training of a Ph.D. student. The principal investigator is committed to training of the next generation leaders of diverse background (and professional interests). He also is involved with the university's new undergraduate environmental studies program and plans to engage several undergraduate students for honor credits in this project, in the area of processing and analysis of satellite imagery.