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Satellite infrared data and in situ data were combined to study synoptic-scale and mesoscale fronts in the Gulf of Mexico in the period 1973-1977. Deep northward penetrations of the Loop Current were noted in the winter, and a major warm gyre developed in the winter, 1974. Other major warm gyres were seen to develop in the early spring (1974 and 1977). In all cases, a very large meander developed off the southern part of the west Florida shelf prior to the development of the major warm gyre. Smaller meanders were seen to move along the Loop Current boundary at an average speed of 28 kin/day and with an average wavelength of 210 kin. I present affiliation: theAtlantic Oceanographic and Meteorological Laboratory, Miami, Florida 33149. Paper number 9C 1319. 0148-0227/79/009C-1319501.00 coordinates), and the feature was transferred to a scaled map of the region of interest. Because there were a considerable number of landmarks in the Gulf of Mexico, it is estimated that there was, at most, a 10%-km error in gridding the satellite images and transferring features to scale maps. The analyses of the scale maps are used to develop statistics on the perturbation of interest (e.g., lifetime, speed, stationarity, maximum and minimum dimensions, etc.).In some months, particularly June-September (but in some cases May and October also), the thermal contrast at the surface was not sufficient to detect oceanic features using satellite infrared radiometry. This does not mean that features, such as the Loop Current or boundary eddies, did not exist, but simply means that there was no thermal manifestation of the feature at the surface. For example, it has been shown that a well-developed Loop Current exists in the Gulf of Mexico in the summer. Meanders and eddies associated with the Loop Current would also exist at that time of year; the fact that statistics on such features were determined for the fall, winter, and spring should not be interpreted to mean that such features did not exist in the summer or are necessarily more common in the fall, winter, and spring.The infrared imagery yields the relative variation of sea surface temperature and was used to define ocean surface thermal boundaries (fronts) quite well. In order to obtain absolute values of temperature from the IR data, ground truth calibrations were required. The ground truth calibrations were determined from in situ surface and subsurface temperature data, for the period 1973-1977, obtained from the National Oceanographic Data Center (NODC) and the National Climatic Center (NCC). The in situ data were used to determine specific magriit.udes of sea surface temperature for perturbations of interest. In order to accomplish this, areas on the cold and warm side of specific thermal perturbations were defined by noting latitude and longitude boundaries of each area. The latitude and longitude boundaries, together with information on the period (day, month, and year), were used as input parameters for an algorithm that searched the in situ data files to determine whether ...

No abstract

Sea level measurements from tide gauges at Miami, Florida, and Cat Cay, Bahamas, and bottom pressure measurements from a water depth of 50 meters off Jupiter, Florida, and a water depth of 10 meters off Memory Rock, Bahamas, were correlated with 81 concurrent direct volume transport observations in the Straits of Florida. Daily-averaged sea level from either gauge on the Bahamian side of the Straits was poorly correlated with transport. Bottom pressure off Jupiter had a linear coefficient of determination ofr(2) = 0.93, and Miami sea level, when adjusted for weather effects, had r(2) = 0.74; the standard errors of estimating transports were +/- 1.2 x 10(6) and +/- 1.9 x 10(6) cubic meters per second, respectively. A linear multivariate regression, which combined bottom pressure, weather, and the submarine cable observations between Jupiter and the Bahamas, had r(2) = 0.94 with a standard error of estimating transport of +/- 1.1 x 10(6) cubic meters per second. These results suggest that a combination of easily obtained observations is sufficient to adequatelv monitor the daily volume transport fluctuations of the Florida Current.