Despite the importance of flow through the Yucatan Strait as a major component of the subtropical gyre that feeds the Gulf Stream, and recent additional observations, little is known about the forcing and physical parameters that relate to the current structures in the Strait. This paper attempts to improve our understanding of the flow through the Strait with a detailed analysis of the currents extracted from a five-year, primitive-equation model of the circulation in the Gulf of Mexico and the Caribbean Sea. The analysis is in two parts: firstly, a comparison with observations of the overall statistics – the Loop Current (LC) variability and periods of Loop Current Eddy (LCE) shedding, as well as the means and standard deviations (SD) of transports and currents, and secondly an Empirical Orthogonal Function (EOF) and coherency analysis that attempts to identify the forcing and physical parameters responsible for the dominant modal fluctuations in the Strait. The model LC sheds seven LCEs in four years (allowing one-year spin-up) at irregular time intervals (6.6, 7.1, 5.3, 11.9, 4.2, 10.9) months. The model’s upper (thickness ~800m) inflow into the Gulf of Mexico occupies two-thirds of the Strait on the western side, with a near-surface maximum (4-year) mean of around 1.5 m s and SD ≈ 0.4 m s. Three (return) outflow regions are identified, one in the upper layer (thickness ~ 600m) on the eastern third of the strait, with mean near the surface of about 0.2 m s and SD ≈ 0.14 m s, and two deep outflow cores, along the western and eastern slopes of the strait, with (Mean, SD) ≈ (0.17,0.05) and (0.09,0.07) m s, respectively. These flow structures, and values of the means and variances, as well as the range of variations in the modeled Strait transport, from 16 to 34 Sv (1 Sverdrup = 10 m s), agree quite well with observations by Maul et al. (1985), Ochoa et al. (2001), and Sheinbaum et al. (2002). The deep return transport below 800 m was found to correlate with changes in the Loop Current extension area, in agreement with the observational analysis by Bunge et al. (2001).
[1]
David M. Fratantoni,et al.
On the Atlantic inflow to the Caribbean Sea
,
2002
.
[2]
J. Sheinbaum,et al.
Flow structure and transport in the Yucatan Channel
,
2002
.
[3]
J. Sheinbaum,et al.
Geostrophy via potential vorticity inversion in the Yucatan Channel
,
2001
.
[4]
Molly O. Baringer,et al.
Sixteen years of Florida Current Transport at 27° N
,
2001
.
[5]
M. Inoue,et al.
Loop Current rings and the deep circulation in the Gulf of Mexico
,
2000
.
[6]
Robert R. Leben,et al.
Frequency of Ring Separations from the Loop Current in the Gulf of Mexico: A Revised Estimate
,
2000
.
[7]
G. Mellor.
USERS GUIDE for A THREE-DIMENSIONAL, PRIMITIVE EQUATION, NUMERICAL OCEAN MODEL
,
1998
.
[8]
L. Oey.
Simulation of Mesoscale Variability in the Gulf of Mexico: Sensitivity Studies, Comparison with Observations, and Trapped Wave Propagation
,
1996
.
[9]
W. Sturges.
The frequency of ring separations from the loop current
,
1994
.
[10]
J. C. Evans,et al.
Separation of Warm-Core Rings in the Gulf of Mexico
,
1993
.
[11]
Ping Chen,et al.
A model simulation of circulation in the northeast Atlantic shelves and seas
,
1992
.
[12]
Catherine A. Smith,et al.
An Intercomparison of Methods for Finding Coupled Patterns in Climate Data
,
1992
.
[13]
W. Teague,et al.
A Comparison Between the Generalized Digital Environmental Model and Levitus climatologies
,
1990
.
[14]
D. Mayer,et al.
Comparisons between a continuous 3‐year current‐meter observation at the sill of the Yucatan Strait, satellite measurements of Gulf Loop Current area, and regional sea level
,
1985
.
[15]
H. Hurlburt,et al.
A Numerical Study of Loop Current Intrusions and Eddy Shedding
,
1980
.