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 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 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. 

scholarly journals Loop Current Variability as Trigger of Coherent Gulf Stream Transport Anomalies

2019 ◽  
Vol 49 (8) ◽  
pp. 2115-2132 ◽  
Author(s):  
Joël J.-M. Hirschi ◽  
Eleanor Frajka-Williams ◽  
Adam T. Blaker ◽  
Bablu Sinha ◽  
Andrew Coward ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Gulf Stream ◽  
Time Lag ◽  
Ocean Model ◽  
Surface Velocity ◽  
Loop Current ◽  
Intrinsic Variability ◽  
Cape Hatteras ◽  
Florida Straits ◽  
Stream Transport

AbstractSatellite observations and output from a high-resolution ocean model are used to investigate how the Loop Current in the Gulf of Mexico affects the Gulf Stream transport through the Florida Straits. We find that the expansion (contraction) of the Loop Current leads to lower (higher) transports through the Straits of Florida. The associated surface velocity anomalies are coherent from the southwestern tip of Florida to Cape Hatteras. A simple continuity-based argument can be used to explain the link between the Loop Current and the downstream Gulf Stream transport: as the Loop Current lengthens (shortens) its path in the Gulf of Mexico, the flow out of the Gulf decreases (increases). Anomalies in the surface velocity field are first seen to the southwest of Florida and within 4 weeks propagate through the Florida Straits up to Cape Hatteras and into the Gulf Stream Extension. In both the observations and the model this propagation can be seen as pulses in the surface velocities. We estimate that the Loop Current variability can be linked to a variability of several Sverdrups (1Sv = 106 m3 s−1) through the Florida Straits. The exact timing of the Loop Current variability is largely unpredictable beyond a few weeks and its variability is therefore likely a major contributor to the chaotic/intrinsic variability of the Gulf Stream. However, the time lag between the Loop Current and the flow downstream of the Gulf of Mexico means that if a lengthening/shortening of the Loop Current is observed this introduces some predictability in the downstream flow for a few weeks.

The Intra-Americas Springtime Sea Surface Temperature Anomaly Dipole as Fingerprint of Remote Influences

2010 ◽  
Vol 23 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Ernesto Muñoz ◽  
Chunzai Wang ◽  
David Enfield
Keyword(s):  
Gulf Of Mexico ◽  
North Atlantic ◽  
Caribbean Sea ◽  
Enso Event ◽  
Shortwave Radiation ◽  
Teleconnection Patterns ◽  
The North ◽  
The Pacific ◽  
Sst Anomaly ◽  
The Caribbean

Abstract The influence of teleconnections on the Intra-Americas Sea (IAS; Gulf of Mexico and Caribbean Sea) has been mostly analyzed from the perspective of El Niño–Southern Oscillation (ENSO) on the Caribbean Sea (the latter being an extension of the tropical North Atlantic). This emphasis has overlooked both 1) the influence of other teleconnections on the IAS and 2) which teleconnections affect the Gulf of Mexico climate variability. In this study the different fingerprints that major teleconnection patterns have on the IAS during boreal spring are analyzed. Indices of teleconnection patterns are regressed and correlated to observations of oceanic temperature and atmospheric data from reanalyses and observational datasets. It is found that the Pacific teleconnection patterns that influence the IAS SSTs do so by affecting the Gulf of Mexico in an opposite manner to the Caribbean Sea. These analyzed Pacific climate patterns are the Pacific–North American (PNA) teleconnection, the Pacific decadal oscillation (PDO), and ENSO. The North Atlantic Oscillation (NAO) is related to a lesser degree with the north–south SST anomaly dipole than are Pacific teleconnection patterns. It is also found that the IAS influence from the midlatitude Pacific mostly affects the Gulf of Mexico, whereas the influence from the tropical Pacific mostly affects the Caribbean Sea. Therefore, the combination of a warm ENSO event and a positive PNA event induces a strong IAS SST anomaly dipole between the Gulf of Mexico and the Caribbean Sea during spring. By calculating an index that represents the IAS SST anomaly dipole, it is found that the dipole forms mostly in response to changes in the air–sea heat fluxes. In the Gulf of Mexico the dominant mechanisms are the air–sea differences in humidity and temperature. The changes in shortwave radiation also contribute to the dipole of net air–sea heat flux. The changes in shortwave radiation arise, in part, by the cloudiness triggered by the air–sea differences in humidity, and also by the changes in the convection cell that connects the Amazon basin to the IAS. Weaker Amazon convection (e.g., in the event of a warm ENSO event) reduces the subsidence over the IAS, and henceforth the IAS cloudiness increases (and the shortwave radiation decreases). This study contributes to a greater understanding of how the IAS is influenced by different Pacific and Atlantic teleconnections.

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