scholarly journals The Surface Circulation of the Caribbean Sea and the Gulf of Mexico as Inferred from Satellite Altimetry

2009 ◽  
Vol 39 (3) ◽  
pp. 640-657 ◽  
Author(s):  
Aida Alvera-Azcárate ◽  
Alexander Barth ◽  
Robert H. Weisberg
Keyword(s):  
Gulf Of Mexico ◽  
Time Scales ◽  
Satellite Altimetry ◽  
Southern Oscillation ◽  
Caribbean Sea ◽  
Vertical Shear ◽  
Loop Current ◽  
Surface Circulation ◽  
The Caribbean ◽  
Anticyclonic Eddies

Abstract The surface circulation of the Caribbean Sea and Gulf of Mexico is studied using 13 years of satellite altimetry data. Variability in the Caribbean Sea is evident over several time scales. At the annual scale, sea surface height (SSH) varies mainly by a seasonal steric effect. Interannually, a longer cycle affects the SSH slope across the current and hence the intensity of the Caribbean Current. This cycle is found to be related to changes in the wind intensity, the wind stress curl, and El Niño–Southern Oscillation. At shorter time scales, eddies and meanders are observed in the Caribbean Current, and their propagation speed is explained by baroclinic instabilities under the combined effect of vertical shear and the β effect. Then the Loop Current (LC) is considered, focusing on the anticyclonic eddies shed by it and the intrusion of the LC into the Gulf of Mexico through time. Twelve of the 21 anticyclonic eddies observed to detach from the LC are shed from July to September, suggesting a seasonality in the timing of these events. Also, a relation is found between the intrusion of the LC into the Gulf of Mexico and the size of the eddies shed from it: larger intrusions trigger smaller eddies. A series of extreme LC intrusions into the Gulf of Mexico, when the LC is observed as far as 92°W, are described. The analyses herein suggest that the frequency of such events has increased in recent years, with only one event occurring in 1993 versus three from 2002 to 2006. Transport through the Straits of Florida appears to decrease during these extreme intrusions.

scholarly journals Eddy and Wind-Forced Heat Transports in the Gulf of Mexico

2010 ◽  
Vol 40 (12) ◽  
pp. 2728-2742 ◽  
Author(s):  
Y-L. Chang ◽  
L-Y. Oey
Keyword(s):  
Gulf Of Mexico ◽  
Heat Content ◽  
Caribbean Sea ◽  
Ocean Model ◽  
Western Coast ◽  
Loop Current ◽  
Southern Side ◽  
The Caribbean ◽  
Zero Potential ◽  
Wind Mixing

Abstract The Gulf of Mexico (GOM) receives heat from the Caribbean Sea via the Yucatan–Loop Current (LC) system, and the corresponding ocean heat content (OHC) is important to weather and climate of the continental United States. However, the mechanisms that affect this heat influx and how it is distributed in the Gulf have not been studied. Using the Princeton Ocean Model, the authors show that a steady, uniform westward wind in the Gulf increases (∼100 KJ cm−2) the upper OHC (temperature T > 18°C) of the Gulf. This is because wind increases the water exchange between the Gulf and the Caribbean Sea, and the heat input into the Gulf is also increased, by about 50 TW. The westward heat transport to the western Gulf is ∼30 TW, and a substantial portion of this is due to wind-induced shelf currents, which converge to produce downwelling near the western coast. Finally, eddies are effective transporters of heat across the central Gulf. Wind forces larger LC and rings with deeper isotherms. This and downfront-wind mixing on the southern side of anticyclonic rings, northward spread of near-zero potential vorticity waters, and downwelling on the northern shelf break result in wide and deep eddies that transport large OHCs across the Gulf.

scholarly journals The impact of upwelling on the intensification of anticyclonic ocean eddies in the Caribbean Sea

Ocean Science ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1419-1437 ◽  
Author(s):  
Carine G. van der Boog ◽  
Julie D. Pietrzak ◽  
Henk A. Dijkstra ◽  
Nils Brüggemann ◽  
René M. van Westen ◽  
...  
Keyword(s):  
Coastal Upwelling ◽  
Caribbean Sea ◽  
Vertical Shear ◽  
Ekman Transport ◽  
Density Gradients ◽  
River Plumes ◽  
Salinity Gradients ◽  
The Caribbean ◽  
Anticyclonic Eddies ◽  
The Impact

Abstract. The mesoscale variability in the Caribbean Sea is dominated by anticyclonic eddies that are formed in the eastern part of the basin. These anticyclones intensify on their path westward while they pass the coastal upwelling region along the Venezuelan and Colombian coast. In this study, we used a regional model to show that this westward intensification of Caribbean anticyclones is steered by the advection of cold upwelling filaments. Following the thermal wind balance, the increased horizontal density gradients result in an increase in the vertical shear of the anticyclones and in their westward intensification. To assess the impact of variations in upwelling on the anticyclones, several simulations were performed in which the northward Ekman transport (and thus the upwelling strength) is altered. As expected, stronger (weaker) upwelling is associated with stronger (weaker) offshore cooling and a stronger (weaker) westward intensification of the anticyclones. Moreover, the simulations with weaker upwelling show farther advection of the Amazon and Orinoco River plumes into the basin. As a result, in these simulations the horizontal density gradients were predominantly set by horizontal salinity gradients. The importance of the horizontal density gradients driven by temperature, which are associated with the upwelling, increased with increasing upwelling strength. The results of this study highlight that both upwelling and the advection of the river plumes affect the life cycle of mesoscale eddies in the Caribbean Sea.

scholarly journals A Trigger Mechanism for Loop Current Ring Separations

2010 ◽  
Vol 40 (5) ◽  
pp. 900-913 ◽  
Author(s):  
Wilton Sturges ◽  
Nicholas G. Hoffmann ◽  
Robert R. Leben
Keyword(s):  
Gulf Of Mexico ◽  
Sea Level ◽  
Satellite Altimetry ◽  
Loop Current ◽  
Trigger Mechanism ◽  
Sea Levels ◽  
Delay Times ◽  
The Caribbean ◽  
Florida Straits ◽  
Current Ring

Abstract The Loop Current in the Gulf of Mexico sheds large anticyclonic rings on an irregular basis. The authors attempt to show what actually triggers the ring separations. Pulses of increased transport through the Florida Straits, as observed by the cable data, are observed prior to each ring separation. This finding is consistent over all separation events observed in the satellite altimetry record. The pulses of transport occur approximately two to four weeks before the rings separate. The increase in transport is usually accompanied by a corresponding increase in offshore sea level, suggesting forcing from the open ocean. The delay times between the pulses of increased transport and ring separations can be shown to be significantly correlated with the length of the Loop Current. Mean sea levels over the Caribbean and Gulf also peak before the separations, on average.

scholarly journals The Impact of Upwelling on the Intensification of Anticyclonic Ocean Eddies in the Caribbean Sea

2019 ◽  
Author(s):  
Carine G. van der Boog ◽  
Julie D. Pietrzak ◽  
Henk A. Dijkstra ◽  
Nils Brüggemann ◽  
René M. van Westen ◽  
...  
Keyword(s):  
Coastal Upwelling ◽  
Caribbean Sea ◽  
Vertical Shear ◽  
Ekman Transport ◽  
Density Gradients ◽  
River Plumes ◽  
The Caribbean ◽  
Western Side ◽  
Anticyclonic Eddies ◽  
The Impact

Abstract. The mesoscale variability in the Caribbean Sea is dominated by anticyclonic eddies that are formed in the eastern part of the basin. These anticyclones intensify on their path westward while they pass the coastal upwelling region along the Venezuelan and Colombian coast. In this study, we used a regional model to show that this westward intensification of Caribbean anticyclones is driven by the advection of cold upwelling filaments. These dense filaments are advected by the anticyclones, leading to an increase of the horizontal density gradients at the western side of the anticyclones. Following the thermal wind balance, the increased density gradients result in an increase of the vertical shear of the anticyclones and to their westward intensification. To assess the impact of variations in upwelling on the anticyclones, several simulations were performed in which the northward Ekman transport (and thus the upwelling strength) is altered. As expected, stronger (weaker) upwelling is associated with more stronger (weaker) offshore cooling and a more (less) westward intensification of the anticyclones. The simulations with weaker upwelling show farther advection of the Amazon and Orinoco River plumes into the basin. The dispersion of the river plumes affects the formation process of the anticyclones, where the horizontal density gradients were mainly determined by the salinity gradients of the river plume and not by temperature gradients that were associated with upwelling.

scholarly journals Nonlinear analysis of the occurrence of hurricanes in the Gulf of Mexico and the Caribbean Sea

2018 ◽  
Vol 25 (2) ◽  
pp. 291-300 ◽  
Author(s):  
Berenice Rojo-Garibaldi ◽  
David Alberto Salas-de-León ◽  
María Adela Monreal-Gómez ◽  
Norma Leticia Sánchez-Santillán ◽  
David Salas-Monreal
Keyword(s):  
Time Series ◽  
Gulf Of Mexico ◽  
Nonlinear Analysis ◽  
Chaotic Behavior ◽  
Caribbean Sea ◽  
Historical Record ◽  
Nonlinear Analyses ◽  
The North ◽  
The Caribbean ◽  
The Individual

Abstract. Hurricanes are complex systems that carry large amounts of energy. Their impact often produces natural disasters involving the loss of human lives and materials, such as infrastructure, valued at billions of US dollars. However, not everything about hurricanes is negative, as hurricanes are the main source of rainwater for the regions where they develop. This study shows a nonlinear analysis of the time series of the occurrence of hurricanes in the Gulf of Mexico and the Caribbean Sea obtained from 1749 to 2012. The construction of the hurricane time series was carried out based on the hurricane database of the North Atlantic basin hurricane database (HURDAT) and the published historical information. The hurricane time series provides a unique historical record on information about ocean–atmosphere interactions. The Lyapunov exponent indicated that the system presented chaotic dynamics, and the spectral analysis and nonlinear analyses of the time series of the hurricanes showed chaotic edge behavior. One possible explanation for this chaotic edge is the individual chaotic behavior of hurricanes, either by category or individually regardless of their category and their behavior on a regular basis.

scholarly journals A Lagrangian approach to the Loop Current eddy separation

2013 ◽  
Vol 20 (1) ◽  
pp. 85-96 ◽  
Author(s):  
F. Andrade-Canto ◽  
J. Sheinbaum ◽  
L. Zavala Sansón
Keyword(s):  
Numerical Model ◽  
Gulf Of Mexico ◽  
Caribbean Sea ◽  
Separation Process ◽  
Sea Surface ◽  
Loop Current ◽  
Hyperbolic Point ◽  
Finite Time Lyapunov Exponents ◽  
Florida Straits ◽  
Strain Direction

Abstract. Determining when and how a Loop Current eddy (LCE) in the Gulf of Mexico will finally separate is a difficult task, since several detachment re-attachment processes can occur during one of these events. Separation is usually defined based on snapshots of Eulerian fields such as sea surface height (SSH) but here we suggest that a Lagrangian view of the LCE separation process is more appropriate and objective. The basic idea is very simple: separation should be defined whenever water particles from the cyclonic side of the Loop Current move swiftly from the Yucatan Peninsula to the Florida Straits instead of penetrating into the NE Gulf of Mexico. The properties of backward-time finite time Lyapunov exponents (FTLE) computed from a numerical model of the Gulf of Mexico and Caribbean Sea are used to estimate the "skeleton" of flow and the structures involved in LCE detachment events. An Eulerian metric is defined, based on the slope of the strain direction of the instantaneous hyperbolic point of the Loop Current anticyclone that provides useful information to forecast final LCE detachments. We highlight cases in which an LCE separation metric based on SSH contours (Leben, 2005) suggests there is a separated LCE that later reattaches, whereas the slope method and FTLE structure indicate the eddy remains dynamically connected to the Loop Current during the process.

New species of Pseudonereis Kinberg, 1865 (Polychaeta: Nereididae) from the Atlantic Ocean, and a review of paragnath morphology and methodology

Zootaxa ◽  
2018 ◽  
Vol 4471 (2) ◽  
pp. 245 ◽  
Author(s):  
VÍCTOR M. CONDE-VELA
Keyword(s):  
New Species ◽  
Atlantic Ocean ◽  
Gulf Of Mexico ◽  
Caribbean Sea ◽  
Distinct Species ◽  
Eastern Pacific ◽  
Type Locality ◽  
Gulf Of Guinea ◽  
Undescribed Species ◽  
The Caribbean

Pseudonereis gallapagensis Kinberg, 1865 and P. variegata (Grube & Kröyer in Grube, 1858) are the only two species of this genus commonly recorded along Atlantic American coasts, but their type localities are in the Eastern Pacific, and their morphology differs. Two new Pseudonereis species are described from Eastern Mexico: P. brunnea sp. n. from the Gulf of Mexico, and P. citrina sp. n. from the Caribbean Sea, previously confused with P. gallapagensis. In order to facilitate comparisons, descriptions based on specimens from near the type locality for P. gallapagensis (Peru and Ecuador), and topotypes for P. variegata (Valparaiso, Chile), are included. Based on these comparisons and current descriptions, the synonymies of Nereis ferox Hansen, 1882 described from Brazil with P. variegata, and of Pseudonereis formosa Kinberg, 1865 described from Hawaii with P. gallapagensis, are rejected. Consequently, both are regarded as distinct species and revised diagnoses are provided for them. The record of P. ferox from the Gulf of Guinea proved to be an undescribed species, and is herein described as P. fauveli sp. n. The number of paragnath rows in nereidid pharynx areas VII–VIII has been interpreted in several ways, leading to confusion; an alternative method to determine the number of bands and rows is proposed. The midventral region, the division of areas VII–VIII in furrow and ridge regions, and the description of the arrangement based on the pattern of paragnaths in such regions, are proposed. Further, the terms shield-shaped and pointed (P-bars) bars are redefined, and a new term, crescent-shaped bars, is proposed for paragnaths in the areas VI in some Pseudonereis and Perinereis species. A key for all Pseudonereis species is also included. 

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