Nonlocal impacts of the Loop Current on cross-slope near-bottom flow in the northeastern Gulf of Mexico

2015 ◽  
Vol 42 (8) ◽  
pp. 2926-2933 ◽  
Author(s):  
Thanh-Tam Nguyen ◽  
Steven L. Morey ◽  
Dmitry S. Dukhovskoy ◽  
Eric P. Chassignet
Keyword(s):  
Gulf Of Mexico ◽  
Loop Current ◽  
Northeastern Gulf Of Mexico

scholarly journals SEASONAL VARIABILITY OF LIGHT ABSORPTION COEFFICIENT OF SURFACE WATER

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Bisman Nababan ◽  
Denny A. Wiguna ◽  
Risti E. Arhatin
Keyword(s):  
Gulf Of Mexico ◽  
Absorption Coefficient ◽  
Loop Current ◽  
Surface Absorption ◽  
Average Value ◽  
Run Off ◽  
Significant Difference ◽  
Coefficient Measurement ◽  
Northeastern Gulf Of Mexico ◽  
Offshore Region

Absorption coefficient measurement can be used in estimating water quality, optical characteristic of water column, and marine bio-optical models. The purposes of this research were to determine values and variability of sea surface absorption coefficient in the northeastern Gulf of Mexico (NEGOM) based on various seasons. The data were collected in spring, summer, and fall seasons in 1999-2000 with AC-9 instrument. The spatial distribution of absorption coefficient showed that relatively high values were generally found along the run off Missisippi, Mobile, Chochawati, Escambia, Apalachicola, and Suwannee rivers, as well as Tampa Bay. Meanwhile, relatively low values were found in offshore region. This pattern followed the distribution pattern of chlorophyll and CDOM. Based on the local region comparison of spectral average value of absorption coefficient, we found a significant difference (α = 95%) among regions with the highest value in the run off of the Mississippi and Mobile rivers, and the lowest value in the offshore region. Comparison of spectral average value of absorption coefficient among seasons at the three primary wavelengths (blue=440 nm, green=510 nm, and red=676 nm) also showed a significant difference (α = 95%) with the highest value during the summer 1999 (Su-99) and the lowest value during the spring of 2000 (Sp-00). Absorption coefficient values were influenced by oceanographic factors that varied in every season such as wind, surface currents, upwelling, the location and speed of the Loop Current, and the river discharge of fresh water into the NEGOM.Keywords: absorption coefficient, seasons, chlorophyll, CDOM, northeastern Gulf of Mexico

Subinertial Slope-Trapped Waves in the Northeastern Gulf of Mexico

2009 ◽  
Vol 39 (6) ◽  
pp. 1475-1485 ◽  
Author(s):  
Z. R. Hallock ◽  
W. J. Teague ◽  
E. Jarosz
Keyword(s):  
Gulf Of Mexico ◽  
Current Velocity ◽  
Kelvin Waves ◽  
Loop Current ◽  
Mobile Bay ◽  
The West ◽  
Direct Forcing ◽  
Northeastern Gulf Of Mexico ◽  
The Waves ◽  
Acoustic Doppler Current Profilers

Abstract Current velocity from moored arrays of acoustic Doppler current profilers (ADCPs) deployed on the outer shelf and slope, south of Mobile Bay in the northeastern Gulf of Mexico, shows evidence of alongslope, generally westward-propagating subinertial baroclinic Kelvin waves with periods of about 16 and 21 days, amplitudes of 5–10 cm s−1, and wavelengths of about 500 km. The observed waves were highly coherent over the slope between about 200 and 500 m and accounted for a significant amount of the current variability below 200 m. The source of the waves could be attributed to effects of the Loop Current on the west Florida slope but is more likely due to direct forcing by Loop Current–generated eddies impacting the experimental area.

scholarly journals SEASONAL VARIABILITY OF LIGHT ABSORPTION COEFFICIENT OF SURFACE WATER

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Bisman Nababan ◽  
Denny A. Wiguna ◽  
Risti E. Arhatin
Keyword(s):  
Gulf Of Mexico ◽  
Absorption Coefficient ◽  
Loop Current ◽  
Surface Absorption ◽  
Average Value ◽  
Light Absorption Coefficient ◽  
Run Off ◽  
Significant Difference ◽  
Northeastern Gulf Of Mexico ◽  
Offshore Region

<p><em>Absorption coefficient </em><em>measurement can </em><em>be </em><em>use</em><em>d</em><em> in</em><em> </em><em>estimat</em><em>ing</em><em> water quality, </em><em>op</em><em>t</em><em>ical </em><em>characteristic of water column, and </em><em>marine </em><em>bio-optical models. The purposes of this research were to determine values and variability of sea surface absorption coefficient in the northeastern Gulf of Mexico (NEGOM) based on various seasons. The data were collected </em><em>in</em><em> spring, summer, and fall seasons in 1999-2000 with AC-9 instrument. The spatial distribution of absorption coefficient showed that relatively high values </em><em>were </em><em>generally found along the run off Missisippi, Mobile, Chochawati, Escambia, Apalachicola, and Suwannee rivers, as well as Tampa Bay. Meanwhile, relatively low values were found in offshore region. </em><em>This pattern followed the</em><em> distribution pattern of chlorophyll and CDOM. Based on the local region comparison of spectral average value of absorption coefficient, we found a significant difference (α = 95%) among regions with the highest value in the run off of the Mississippi and Mobile rivers, and the lowest value in the offshore region. Comparison of spectral average value of absorption coefficient among seasons at the three primary wavelengths (blue=440 nm, green=510 nm, and red=676 nm) also showed a significant difference (α = 95%) with the highest value during the summer 1999 (Su-99) and the lowest value during the spring of 2000 (Sp-00). Absorption coefficient values were influenced by oceanographic factors that varied in every season such as wind, surface currents, upwelling, the location and speed of the Loop Current, and the river discharge of fresh water into the NEGOM.</em></p><strong><em>Keywords:</em></strong><em> absorption coefficient, seasons, chlorophyll, CDOM, northeastern Gulf of Mexico</em>

Distributional Differences and Population Similarities for Two Deep-Sea Crabs (Family Geryonidae) in the Northeastern Gulf of Mexico

1990 ◽  
Vol 47 (11) ◽  
pp. 2112-2122 ◽  
Author(s):  
F. D. Lockhart ◽  
W. J. Lindberg ◽  
N. J. Blake ◽  
R. B. Erdman ◽  
H. M. Perry ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Relative Abundance ◽  
Deep Sea ◽  
Seasonal Patterns ◽  
Florida Current ◽  
Loop Current ◽  
Male And Female ◽  
Northeastern Gulf Of Mexico ◽  
Current Circulation ◽  
Depth Zonation

For golden crab, Chaceon fenneri, and red crab, Chaceon quinquedens, numbers per trap, sex, and crab size were tested for broad bathymetric, geographic, and seasonal patterns on the upper continental slope, northeastern Gulf of Mexico. Red crab occupied only the deepest of three sampled depths (i.e. 677 m vs. 494 and 311 m) while golden crab predominated at the upper two. Golden crab occurred adjacent to peninsular Florida, but not along the northern Gulf slope, while red crab occurred across the geographic arc sampled. Relative abundance increased southward for golden crab and northwestward for red crab, while the proportion of females increased counter-clockwise within the sampled range of each species. Golden crab exhibited a Chaceon-typical bathymetric pattern of partial sex segregation and size inversely related to depth, but male and female bathymetric patterns shifted seasonally with lags between geographic areas. Interspecific competition cannot explain the species depth zonation, while geographic and seasonal patterns may relate to Loop Current–Florida Current circulation.

The influence of Gulf of Mexico Loop Current intrusion on the transport of the Florida Current

2010 ◽  
Vol 60 (5) ◽  
pp. 1075-1084 ◽  
Author(s):  
Yuehua Lin ◽  
Richard J. Greatbatch ◽  
Jinyu Sheng
Keyword(s):  
Gulf Of Mexico ◽  
Florida Current ◽  
Loop Current

Sediment types determination using acoustic techniques in the Northeastern Gulf of Mexico

2004 ◽  
Vol 8 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Gil Young Kim ◽  
Michael D. Richardson ◽  
Dale L. Bibee ◽  
Dae Choul Kim ◽  
Roy H. Wilkens ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Sediment Types ◽  
Acoustic Techniques ◽  
Northeastern Gulf Of Mexico

Development of a Stepped Line Tensioning Solution for Mitigating VIM Effects in Loop Eddy Currents for the Genesis Spar

2004 ◽  
Author(s):  
T. Kokkinis ◽  
R. E. Sandstro¨m ◽  
H. T. Jones ◽  
H. M. Thompson ◽  
W. L. Greiner
Keyword(s):  
Gulf Of Mexico ◽  
Eddy Current ◽  
Eddy Currents ◽  
Comprehensive Evaluation ◽  
Design Solution ◽  
Loop Current ◽  
Mooring Lines ◽  
Test Methodology ◽  
Induced Motion ◽  
High Reynolds

A number of spars are being installed in deepwater areas in the Gulf of Mexico (GoM), which are subject to loop / eddy current conditions and must be designed for Vortex-Induced Motion (VIM). This paper shows how recent advances in VIM prediction enabled an efficient and effective mooring design solution for the existing Genesis classic spar, which is installed in Green Canyon Block 205 in the GOM. The solution may also be applicable to new spar designs. During the Gulf of Mexico Millennium Eddy Current event in April 2001, the Genesis spar platform underwent vortex induced motions (VIM) which were greater than anticipated during the design of the mooring & riser systems. Analysis showed that if such large motions were to occur in higher currents in the range of the 100-year event, they could cause significant fatigue damage, and could lead to peak tensions in excess of design allowables. After a comprehensive evaluation of potential solutions, Stepped Line Tensioning (SLT) was determined to be the best approach for restoring the platform’s original mooring capacity on technical, cost and schedule grounds. SLT did not require extensive redesign of the existing mooring system of the spar. Furthermore, SLT provided a means to improve mooring integrity on an interim basis, while completing details for permanent implementation. Under SLT, the pretensions of the mooring lines are adjusted based on forecast currents in order to keep the platform below the VIM lock-in threshold at all times and for all eddy/loop current conditions up to and including the 100-year condition. High Reynolds number model tests conducted with a new test methodology were used to get a reliable prediction of the spar’s VIM response for this evaluation.

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