An analysis of wind-forced, seasonal transport variability at the Florida Straits using linear models of the North Atlantic

• Main Author: Fanning, Augustus F.
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1993
• Subjects: North Atlantic
• Online Access: https://research.library.mun.ca/8610/; https://research.library.mun.ca/8610/1/Fanning_AugustusF.pdf

Two linear models of the North Atlantic, a linear barotropic model and a linear two-density layer model, are employed to investigate the effect of using different wind stress climatologies on the model-calculated transport. Particular emphasis is placed on the model-calculated response at the Florida Straits. The model domains extend from 10°S to 65°N and 100°W to 15°E at 1° x 1° resolution. The wind stress climatologies are those of da Silva et al.(1993a; hereafter DS), Hellerman and Rosenstein (1983; hereafter HR), Isemer and Hasse (1987; hereafter IH) and Trenberth et al. (1990; hereafter TR). Comparing the results at the Florida Straits, we find that for each climatology, the barotropic model shows maximum northward transport in the summer and minima in the fall and late winter, in general agreement with transport measurements from cable data (Larsen, 1992). However, the amplitude of the model response differs considerably between the climatologies. In the case of DS the range (maximum transport minus minimum transport) is 2.8 Sv; HR, 3.6 Sv; TR, 5.2 Sv and IH, 5.9 Sv, compared to a range of 4.6 ± 0.4 Sv derived from cable data. When the JEBAR (Joint Effect of Baroclinicity And Relief; Sarkisyan and Ivanov, 1971) forced transport is also considered, using the two-layer model, the amplitude of the model-calculated response changes slightly in each case, with ranges of 3.3Sv, 3.9Sv, 5.8Sv and 6.1Sv for each of DS, HR, TR, and IH respectively. -- We have also conducted experiments using a 1/3° x 1/3° version of the model applied to the region extending from 5°N to 42°N, and 100°W to 70°W. The Bahama/Antilles Island Arc are resolved in this model. Transport through the boundary at 70°W is specified from the 1° x 1° calculations referred to above. The details of the model-calculated response are particularity sensitive to the precise choice of grid point used to represent the offshore boundary of the Florida Straits. If we choose the Grand Bahama Islands, the cases with transport specified on the eastern boundary ...