Space-time structure and variability of the shelf water-slope water and gulf stream surface temperature fronts and associated warm-core eddies
The space time structure and variability of three thermal features on the surface of the Northwest Atlantic: the shelf water-slope water front; the Gulf Stream front; and warm-core, anticyclonic eddies: were examined between September 1, 1975, and August 31, 1977, using weekly satellite-derived charts of surface temperature fronts. The temporal and spatial correlation scales of both the shelf-slope and Gulf Stream fronts were about 2 weeks and 80 km, respectively. The rms amplitude of both fronts increased from about 25 to 80 km in the first 1,000 km northeastward from Cape Hatteras. The dominant Gulf Stream meanders had wavelengths of about 320 km and periods of 7--8 weeks, and they propagated downstream at a speed of about 6 cm/s. The warm-core eddies averaged about 100 km in diameter and propagated southwestward from Georges Bank at an average speed of 6 cm/s; they decreased in diameter from about 120 to 90 km and increased in speed from about 4 to 7 cm/s in moving from the Georges Bank-to-Hudson Canyon subdomain to the Hudson Canyon-to-Cape Charles subdomain. Some large Gulf Stream meanders induced perturbations of the shelf-slope front. Eddies forced seaward perturbations of the front, which propagated southwestward with the eddies. (There were more rapidly propagating disturbances which also moved southwestward along the shelf-slope front; they may have been due to coastally trapped waves). There was significant interannual variation in the mean position of the Gulf Stream front and the number and intensity of warm-core eddies shed by the Stream, through the correlation scales of its front did not change. Consequently, there were substantial interannual variations in the inferred entrainment of shelf waters by warm-core eddies. Furthermore, the correlation scales of the shelf-slope front had interannual variation.
- Research Organization:
- College of Marine Studies, University of Delaware, Lewes, Delaware 19958
- OSTI ID:
- 5556637
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 84:C12
- Country of Publication:
- United States
- Language:
- English
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