scholarly journals Deep flows in the Yucatan Channel and their relation to changes in the Loop Current extension

2002 ◽  
Vol 107 (C12) ◽  
pp. 26-1-26-7 ◽  
Author(s):  
L. Bunge ◽  
J. Ochoa ◽  
A. Badan ◽  
J. Candela ◽  
J. Sheinbaum
Keyword(s):  
Loop Current ◽  
Yucatan Channel

scholarly journals Transports through the Straits of Florida

2005 ◽  
Vol 35 (3) ◽  
pp. 308-322 ◽  
Author(s):  
Peter Hamilton ◽  
Jimmy C. Larsen ◽  
Kevin D. Leaman ◽  
Thomas N. Lee ◽  
Evans Waddell
Keyword(s):  
Gulf Of Mexico ◽  
North Atlantic Ocean ◽  
Florida Current ◽  
Loop Current ◽  
Straits Of Florida ◽  
Key West ◽  
The North ◽  
Side Channels ◽  
Yucatan Channel ◽  
Accurate Indicator

Abstract Transports were calculated for four sections of the Florida Current from Key West to Jupiter, Florida, using a moored current-meter array and voltages from cross-channel telephone cables at the western and northern ends of the Straits of Florida. In addition, moored arrays were used to estimate transport through the Northwest Providence, Santaren, and Old Bahama Channels that connect the Florida Current to the southwestern part of the North Atlantic Ocean. Transport measurements were obtained for an 11-month period from December 1990 to November 1991. Mean transports of ∼25 Sv (1 Sv ≡ 106 m3 s−1) for the flow across the western ends of the straits, which agree quite well with recent estimates of 23.8 ± 1 Sv entering the Gulf of Mexico through the Yucatan Channel, were obtained from both the Key West to Havana cable and the moored array. This estimate is about 5 Sv less than the generally accepted transport through the northern end of the straits at 27°N. This difference was partially accounted for by inflows through the side channels with more transport from the Old Bahama than the Northwest Providence Channel. The variability in the southern part of the straits was larger than at 27°N and included large diversions of the Florida Current south of the Cay Sal Bank and into the Santaren Channel that were caused by large meanders of the flow. The variability of transport in the side channels contributed to the variability of the Florida Current and reduces the correlations of the transports at the ends of the straits. Therefore, the well-measured transport at 27°N is not an accurate indicator of the transport of the Loop Current out of the Gulf of Mexico.

scholarly journals Deep Cyclonic Circulation in the Gulf of Mexico

2005 ◽  
Vol 35 (10) ◽  
pp. 1801-1812 ◽  
Author(s):  
Christopher J. DeHaan ◽  
Wilton Sturges
Keyword(s):  
Gulf Of Mexico ◽  
Accurate Result ◽  
Sea Water ◽  
Cyclonic Circulation ◽  
Loop Current ◽  
Mean Flow ◽  
Eastern Gulf Of Mexico ◽  
Geostrophic Shear ◽  
Layer Flow ◽  
Yucatan Channel

Abstract The anticyclonic Loop Current dominates the upper-layer flow in the eastern Gulf of Mexico, with a weaker mean anticyclonic pattern in the western gulf. There are reasons, however, to suspect that the deep mean flow should actually be cyclonic. Topographic wave rectification and vortex stretching contribute to this cyclonic tendency, as will the supply of cold incoming deep water at the edges of the basin. The authors find that the deep mean flow is cyclonic both in the eastern and western gulf, with speeds on the order of 1–2 cm s−1 at 2000 m. Historical current-meter mooring data, as well as profiling autonomous Lagrangian circulation explorer (PALACE) floats (at 900 m), suggest that vertical geostrophic shear relative to 1000 m gives a surprisingly accurate result in the interior of the basin. The temperature around the edges of the basin at 2000 m is coldest near the Yucatan Channel, where Caribbean Sea water is colder by ∼0.1°C. The temperature increases steadily with distance in the counterclockwise direction from the Yucatan, consistent with a deep mean cyclonic boundary flow.

scholarly journals Seasonal Variability of the Transport through the Yucatan Channel from Observations

2020 ◽  
Vol 50 (2) ◽  
pp. 343-360
Author(s):  
Gabriela Athié ◽  
Julio Sheinbaum ◽  
Julio Candela ◽  
José Ochoa ◽  
Paula Pérez-Brunius ◽  
...  
Keyword(s):  
Time Series ◽  
Kinetic Energy ◽  
Wind Stress ◽  
Seasonal Cycle ◽  
Loop Current ◽  
Wind Stress Curl ◽  
Channel Transport ◽  
Statistical Sense ◽  
Yucatan Channel ◽  
Western Side

AbstractThe seasonal cycle of transport through the Yucatan Channel is estimated from 59 months of direct mooring measurements and 23 years of a transport proxy from AVISO sea level across the channel. Both exhibit a seasonal cycle with a maximum in summer (July–August) but have a minimum in March for the mooring and in November for AVISO data. The annual and semiannual harmonics explain respectively 19% (~32%) and 6% (~4%) of the subinertial variance of the moored (proxy) transports. Seasonal variations of zonal wind stress and anticyclonic wind stress curl over the Cayman Sea appear to be positively correlated with transport in Yucatan Channel and the northward extension of the Loop Current during the summer, agreeing to some extent with modeling results previously reported. Transport increments during summer coincide with enhanced regional easterly winds and anticyclonic wind stress curl in 60% of the cases (of 23 years). However, this connection is not as tight as model results suggest during winter. The summer correlation only appears to be valid in a broad statistical sense since it is modulated by large interannual and higher-frequency variability. Moored time series confirm previous results that the transport signal on the western side of the channel is quite different from the total Yucatan Channel transport and that eddy kinetic energy at higher frequencies (50–100 days) dominates the variability and is characterized by a relatively low net transport signal, with flow of opposite signs on each side of the channel.

scholarly journals Loop Current Growth and Eddy Shedding Using Models and Observations: Numerical Process Experiments and Satellite Altimetry Data

2013 ◽  
Vol 43 (3) ◽  
pp. 669-689 ◽  
Author(s):  
Yu-Lin Chang ◽  
L.-Y. Oey
Keyword(s):  
Trade Wind ◽  
Loop Current ◽  
Reduced Gravity ◽  
Trade Winds ◽  
Numerical Process ◽  
The Asymmetry ◽  
Yucatan Channel ◽  
Satellite Altimetry Data ◽  
Eddy Shedding

Abstract Recent studies on Loop Current’s variability in the Gulf of Mexico suggest that the system may behave with some regularity forced by the biannually varying trade winds. The process is analyzed here using a reduced-gravity model and satellite data. The model shows that a biannual signal is produced by vorticity and transport fluctuations in the Yucatan Channel because of the piling up and retreat of warm water in the northwestern Caribbean Sea forced by the biannually varying trade wind. The Loop grows and expands with increased northward velocity and cyclonic vorticity of the Yucatan Current, and eddies are shed when these are near minima. Satellite sea surface height (SSH) data from 1993 to 2010 are analyzed. These show, consistent with the reduced-gravity experiments and previous studies, a (statistically) significant asymmetric biannual variation of the growth and wane of Loop Current: strong from summer to fall and weaker from winter to spring; the asymmetry being due to the asymmetry that also exists in the long-term observed wind. The biannual signal is contained in the two leading EOF modes, which together explain 47% of the total variance, and which additionally describe the eddy shedding and westward propagation from summer to fall. The EOFs also show connectivity between Loop Current and Caribbean Sea’s variability by mass and vorticity fluxes through the Yucatan Channel.

scholarly journals Mean Flow in the Gulf of Mexico

2008 ◽  
Vol 38 (7) ◽  
pp. 1501-1514 ◽  
Author(s):  
Wilton Sturges ◽  
Kern E. Kenyon
Keyword(s):  
Gulf Of Mexico ◽  
Data Sources ◽  
Loop Current ◽  
Independent Data ◽  
Ekman Pumping ◽  
Mean Flow ◽  
The West ◽  
Net Flux ◽  
Yucatan Channel ◽  
Current Potential

Abstract Several independent data sources suggest that there is a net upper-layer mass flux O(3 Sv) (Sv ≡ 106 m3 s−1) to the west in the central Gulf of Mexico, even though the western gulf is a closed basin. A plausible explanation is that this net flux is pumped downward by the convergent wind-driven Ekman pumping, as is typical of all midlatitude anticlyclonic gyres. The downward flux can follow isopycnals to depths O(500–600 m) and deeper by eddy mixing; a mechanism for forcing deep water to the south through the Yucatan Channel is provided by the intrusion and ring-shedding cycle of the Loop Current. Potential vorticity maps show that a deep flow from the western gulf back to the Yucatan Channel is likely.

scholarly journals An Analysis of Loop Current Frontal Eddies in a ⅙° Atlantic Ocean Model Simulation

2013 ◽  
Vol 43 (9) ◽  
pp. 1924-1939 ◽  
Author(s):  
Haosheng Huang ◽  
Nan D. Walker ◽  
Ya Hsueh ◽  
Yi Chao ◽  
Robert R. Leben
Keyword(s):  
Numerical Model ◽  
Atlantic Ocean ◽  
General Circulation ◽  
Model Simulation ◽  
Ocean Model ◽  
Anticyclonic Eddy ◽  
Loop Current ◽  
Particle Tracking Method ◽  
The Caribbean ◽  
Yucatan Channel

Abstract The Loop Current frontal eddies (LCFEs) refer to cyclonic cold eddies moving downstream along the outside edge of the Loop Current in the eastern Gulf of Mexico. They have been observed by in situ measurements and satellite imagery, mostly downstream of the Campeche Bank continental shelf. Their evolution, simulated by a primitive equation ⅙° and 37-level Atlantic Ocean general circulation numerical model, is described in detail in this study. Some of the simulated LCFEs arise, with the passage through the Yucatan Channel of a Caribbean anticyclonic eddy, as weak cyclones with diameters less than 100 km near the Yucatan Channel. They then grow to fully developed eddies with diameters on the order of 150–200 km while moving along the Loop Current edge. Modeled LCFEs have a very coherent vertical structure with isotherm doming seen from 50- to ~1000-m depth. The Caribbean anticyclone and LCFE are two predominant features in this numerical model simulation, which account for 22% and 10%, respectively, of the short-term (period less than 100 days) temperature variance at 104.5 m in the complex empirical orthogonal function (CEOF) analysis. The source water inside the LCFEs that are generated by Caribbean anticyclonic eddy impingement can be traced back, using a backward-in-time Lagrangian particle-tracking method, to the western edge of the Caribbean Current in the northwest Caribbean Sea and to coastal waters near the northern Yucatan Peninsula. The model results indicating a pairing of anticyclonic and cyclonic eddies within and north of the Yucatan Channel are supported by satellite altimetry measurements during February 2002 when several altimeters were operational.

scholarly journals Is the Loop Current a Chaotic Oscillator?

2007 ◽  
Vol 37 (6) ◽  
pp. 1455-1469 ◽  
Author(s):  
Alexis Lugo-Fernández
Keyword(s):  
Dynamical Systems ◽  
Gulf Of Mexico ◽  
North Atlantic ◽  
Chaotic Oscillator ◽  
Loop Current ◽  
The North ◽  
Short Memory ◽  
The North Atlantic ◽  
Yucatan Channel ◽  
The North Atlantic Oscillation

Abstract Dynamical systems theory is employed to study the irregular Loop Current in the Gulf of Mexico using a short database of shedding periods and north–south positions of the current. Two independent tests based on these data suggest that the Loop Current is not chaotic but behaves as a nonlinear driven and dampened oscillator with a very short memory. It is suggested that this current varies around a limit-cycle elliptical attractor. It was found that the amplitude and period of the oscillation vary at time scales of 3–5 yr, a time scale that agrees with those of the North Atlantic Oscillation (NAO) and/or ENSO; however, it is proposed that NAO provides the link between these systems. The proposed mechanism is the ITCZ changes caused by NAO, which affects the wind strength and the transport across the Yucatan Channel. A forecasting scheme that allows for prediction of the next eddy-shedding period from knowledge of the last shedding event, a condition caused by the short memory of the system, is provided.

scholarly journals The Role of Mesoscale Dynamics over Northwestern Cuba in the Loop Current Evolution in 2010, during the Deepwater Horizon Incident

2021 ◽  
Vol 9 (2) ◽  
pp. 188
Author(s):  
Yannis Androulidakis ◽  
Vassiliki Kourafalou ◽  
Matthieu Le Hénaff ◽  
HeeSook Kang ◽  
Nektaria Ntaganou
Keyword(s):  
Oil Spill ◽  
Deepwater Horizon ◽  
Main Body ◽  
Florida Current ◽  
Loop Current ◽  
Straits Of Florida ◽  
Eddy Activity ◽  
Mesoscale Dynamics ◽  
Resolution Model ◽  
Yucatan Channel

The Loop Current (LC) system controls the connectivity between the northern Gulf of Mexico (GoM) region and the Straits of Florida. The evolution of the LC and the shedding sequence of the LC anticyclonic ring (Eddy Franklin) were crucial for the fate of the hydrocarbons released during the Deepwater Horizon (DwH) oil spill in 2010. In a previous study, we identified LC-related anticyclonic eddies in the southern GoM, named “Cuba anticyclones” (“CubANs”). Here, we investigate the relation between these eddies and LC evolution in 2010, focusing on the DwH period. We use high-resolution model results in tandem with observational data to describe the connection between the LC system evolution within the GoM (LC extensions, Eddy Franklin and LC Frontal Eddies—LCFEs) and the mesoscale dynamics within the Straits of Florida where CubANs propagate. Five periods of CubAN eddy activity were identified during the oil spill period, featuring different formation processes under a combination of local and regional conditions. Most of these cases are related to the retracted LC phases, when the major LC anticyclone (Eddy Franklin in 2010) is detached from the main body and CubAN eddy activity is most likely. However, two cases of CubAN eddy presence during elongated LC were detected, which led to the attenuation of the eastward flows of warm waters through the Straits (Florida Current; outflow), allowing the stronger supply of Caribbean waters through the Yucatan Channel into the Gulf (inflow), which contributed to short-term LC northward extensions. Oceanographic (LCFEs) and meteorological (wind-induced upwelling) conditions contributed to the release of CubANs from the main LC body, which, in tandem with other processes, contributed to the LC evolution during the DwH oil spill incident.

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