Open Access. Powered by Scholars. Published by Universities.®

Marine Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of South Florida

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 211 - 240 of 387

Full-Text Articles in Marine Biology

Prevalence Of External Skin Lesions And Polycyclic Aromatic Hydrocarbon Concentrations In Gulf Of Mexico Fishes, Post-Deepwater Horizon, Steven Murawski, William T. Hogarth, Ernst B. Peebles, Luiz Barbeiri Jan 2014

Prevalence Of External Skin Lesions And Polycyclic Aromatic Hydrocarbon Concentrations In Gulf Of Mexico Fishes, Post-Deepwater Horizon, Steven Murawski, William T. Hogarth, Ernst B. Peebles, Luiz Barbeiri

C-IMAGE Publications

We surveyed offshore fish populations in the Gulf of Mexico in 2011 and 2012, following persistent reports of abnormal skin lesions and other pathologies in the aftermath of the Deepwater Horizon oil spill. The incidence of skin lesions in 2011 sampling was most frequent in some bottom-dwelling species along the continental shelf edge north of the Deepwater Horizon site. Longline surveys revealed that by 2012 the overall frequency of lesions in northern Gulf of Mexico (NGM) fishes in the vicinity of the Deepwater Horizon had declined 53%, with severity also declining. Relatively high concentrations of polycyclic aromatic hydrocarbon (PAH) metabolites …

Go to article

Generalized Additive Models Used To Predict Species Abundance In The Gulf Of Mexico: An Ecosystem Modeling Tool, Michael Drexler, Cameron H. Ainsworth May 2013

Generalized Additive Models Used To Predict Species Abundance In The Gulf Of Mexico: An Ecosystem Modeling Tool, Michael Drexler, Cameron H. Ainsworth

C-IMAGE Publications

Spatially explicit ecosystem models of all types require an initial allocation of biomass, often in areas where fisheries independent abundance estimates do not exist. A generalized additive modelling (GAM) approach is used to describe the abundance of 40 species groups (i.e. functional groups) across the Gulf of Mexico (GoM) using a large fisheries independent data set (SEAMAP) and climate scale oceanographic conditions. Predictor variables included in the model are chlorophyll a, sediment type, dissolved oxygen, temperature, and depth. Despite the presence of a large number of zeros in the data, a single GAM using a negative binomial distribution was suitable …

Go to article

Optical Contrast Of Oil Dispersed In Seawater Under Windy Conditions, Z. Otremba, O. Zielinski, Chuanmin Hu Jan 2013

Optical Contrast Of Oil Dispersed In Seawater Under Windy Conditions, Z. Otremba, O. Zielinski, Chuanmin Hu

C-IMAGE Publications

Oil pollution of natural waters represents a serious threat for aquatic ecosystems, and the assessment of the degree of pollution requiresmeasurement strategies including remote sensing and modeling. While surface oil pollution is relatively easy to detect with radar or opticalremote sensing, underwater oil emulsions can only be detected using visible light as an information carrier. Here the Michelson contrast ofsea area polluted by an oil-in-water emulsion under various wind conditions is simulated through Monte-Carlo modeling. The results showthe premise for optimal direction of observations in which the possibility of detecting the emulsified oil is maximized.

Go to article

Deglacial Abrupt Climate Change In The Atlantic Warm Pool: A Gulf Of Mexico Perspective, Carlie Williams, Benjamin P. Flower, David W. Hastings, Thomas P. Guilderson, Kelly A. Quinn, Ethan A. Goddard Dec 2010

Deglacial Abrupt Climate Change In The Atlantic Warm Pool: A Gulf Of Mexico Perspective, Carlie Williams, Benjamin P. Flower, David W. Hastings, Thomas P. Guilderson, Kelly A. Quinn, Ethan A. Goddard

Marine Science Faculty Publications

During the last deglaciation, Greenland ice core and North Atlantic sediment records exhibit multiple abrupt climate events including the Younger Dryas cold episode (12.9-11.7 ka). However, evidence for the presence of the Younger Dryas in the Gulf of Mexico (GOM) and the relationship between GOM sea surface temperature (SST) and high-latitude climate change is less clear. We present new Mg/Ca-SST records from two varieties of the planktonic foraminifer Globigerinoides ruber (white and pink) to assess northern GOM SST history from approximately 18.4-10.8 ka. Thirty-five accelerator mass spectrometry (AMS) C-14 dates from Orca Basin core MD02-2550 provide excellent age control and …

Go to article

Ocean Mass From Grace And Glacial Isostatic Adjustment, D. Chambers, John Wahr, Mark E. Tamisea, R Steven Nerem Nov 2010

Ocean Mass From Grace And Glacial Isostatic Adjustment, D. Chambers, John Wahr, Mark E. Tamisea, R Steven Nerem

Marine Science Faculty Publications

We examine geoid rates and ocean mass corrections from two published global glacial isostatic adjustment (GIA) models, both of which have been used in previous studies to estimate ocean mass trends from Gravity Recovery and Climate Experiment (GRACE) satellite gravity data. These two models are different implementations of the same ice loading history and use similar mantle viscosity profiles. The model results are compared with each other and with geoid rates determined from GRACE during August 2002 to November 2009. When averaged over the global ocean, the two models have rates that differ by nearly 1 mm yr−1 of …

Go to article

Time Series Of Bio-Optical Properties In A Subtropical Gyre: Implications For The Evaluation Of Interannual Trends Of Biogeochemical Properties, Zhongping Lee, Shaoling Shang, Chuanmin Hu, Marlon Lewis, Robert Arnone, Yonghong Li, Bertrand Lubac Sep 2010

Time Series Of Bio-Optical Properties In A Subtropical Gyre: Implications For The Evaluation Of Interannual Trends Of Biogeochemical Properties, Zhongping Lee, Shaoling Shang, Chuanmin Hu, Marlon Lewis, Robert Arnone, Yonghong Li, Bertrand Lubac

Marine Science Faculty Publications

With a validated Quasi‐Analytical Algorithm, an 11 year (1998–2008) monthly time series of the primary optical properties of waters in the center of the South Pacific gyre was developed from Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer (MODIS). Also derived are chlorophyll a (Chl a) concentrations with the operational empirical algorithms for SeaWiFS and MODIS. The optical properties include the absorption coefficient (at 443 nm) of phytoplankton (aph) and that of the combination of detritus and gelbstoff (adg). From these time series, we further derived their annual background (summer low) …

Go to article

A Global Evaluation Of Ocean Bottom Pressure From Grace, Omct, And Steric-Corrected Altimetry, D. Chambers, Josh K. Willis Aug 2010

A Global Evaluation Of Ocean Bottom Pressure From Grace, Omct, And Steric-Corrected Altimetry, D. Chambers, Josh K. Willis

Marine Science Faculty Publications

Ocean bottom pressure (OBP) from the Gravity Recovery and Climate Experiment (GRACE) and the Ocean Model for Circulation and Tides (OMCT) are compared globally with OBP computed from altimetry corrected for steric variations from Argo floats from January 2005 to December 2007. Two methods of smoothing the GRACE data are examined. The first uses a standard Gaussian smoother with a radius of 300 km. The second method projects those smoothed maps onto empirical orthogonal functions derived from OMCT in a least squares estimation in order to produce maps that better agree with the physical processes embodied by the model. These …

Go to article

On The Recurrent Ulva Prolifera Blooms In The Yellow Sea And East China Sea, Chuanmin Hu, Daqiu Li, Changsheng Chen, Jianzhong Ge, Frank E. Muller-Karger, Junpeng Liu, Feng Yu, Ming-Xia He May 2010

On The Recurrent Ulva Prolifera Blooms In The Yellow Sea And East China Sea, Chuanmin Hu, Daqiu Li, Changsheng Chen, Jianzhong Ge, Frank E. Muller-Karger, Junpeng Liu, Feng Yu, Ming-Xia He

Marine Science Faculty Publications

A massive bloom of the green macroalgae Ulva prolifera (previously known as Enteromorpha prolifera) occurred in June 2008 in the Yellow Sea (YS), resulting in perhaps the largest “green tide” event in history. Using a novel index (Floating Algae Index) and multiresolution remote sensing data from MODIS and Landsat, we show that U. prolifera patches appeared nearly every year between April and July 2000–2009 in the YS and/or East China Sea (ECS), which all originated from the nearshore Subei Bank. A finite volume numerical circulation model, driven by realistic forcing and boundary conditions, confirmed this finding. Analysis of meteorological/environmental …

Go to article

Moderate Resolution Imaging Spectroradiometer (Modis) Observations Of Cyanobacteria Blooms In Taihu Lake, China, Chuanmin Hu, Zhongping Lee, Ronghua Ma, Kun Yu, Daqiu Li, Shaoling Shang Apr 2010

Moderate Resolution Imaging Spectroradiometer (Modis) Observations Of Cyanobacteria Blooms In Taihu Lake, China, Chuanmin Hu, Zhongping Lee, Ronghua Ma, Kun Yu, Daqiu Li, Shaoling Shang

Marine Science Faculty Publications

A novel approach was used with data from the Moderate Resolution Imaging Spectroradiometer (MODIS) to characterize the intense blooms of cyanobacteria (primarily Microcystis aeruginosa) in Taihu Lake, China's third largest freshwater lake. The approach involves first deriving a floating algae index (FAI) based on the medium‐resolution (250 and 500 m) MODIS reflectance data at 645, 859, and 1240 nm after correction of the ozone/gaseous absorption and Rayleigh scattering effects and then objectively determining the FAI threshold value (−0.004) to separate the bloom and nonbloom waters. By definition, the term “bloom” or “floating algae” refers to bloom where cyanobacteria form …

Go to article

Hydrological And Oceanic Effects On Polar Motion From Grace And Models, Shaunggen Jin, Don Chambers, Byron D. Tapley Feb 2010

Hydrological And Oceanic Effects On Polar Motion From Grace And Models, Shaunggen Jin, Don Chambers, Byron D. Tapley

Marine Science Faculty Publications

Terrestrial water storage (TWS) and ocean bottom pressure (OBP) are major contributors to the observed polar motion excitations, second only to atmospheric mass movement. However, quantitative assessment of the hydrological and oceanic effects on polar motion remains unclear because of the lack of global observations. In this paper, hydrological and oceanic mass excitations to polar motion are investigated using monthly TWS and OBP derived from the Gravity Recovery and Climate Experiment (GRACE) for January 2003 until December 2008. The results from this analysis are compared with hydrological model excitations from the European Center for Medium-Range Weather Forecasts (ECMWF) and oceanic …

Go to article

West Florida Shelf: A Natural Laboratory For The Study Of Ocean Acidification, Pamela Hallock, Lisa L. Robbins, Rebekka Larson, Tanya Beck, Patrick Schwing, Michael Martínez-Colón, Brad Gooch Jan 2010

West Florida Shelf: A Natural Laboratory For The Study Of Ocean Acidification, Pamela Hallock, Lisa L. Robbins, Rebekka Larson, Tanya Beck, Patrick Schwing, Michael Martínez-Colón, Brad Gooch

Marine Science Faculty Publications

Declining oceanic pH and carbonate-ion concentrations are well-known consequences of increased atmospheric and surface-ocean partial pressure of carbon dioxide (pCO2). The possible subject of shifts in seawater carbonate chemistry on biocalcification and survival rates of marine organisms provides questions amenable to both experimental and field study (Kleypas and Langdon, 2006). To date, limited quantitative data exist with which to formalize and test hypotheses regarding such impacts, particularly in continental-shelf settings. The continental shelves of Florida provide an ideal natural laboratory in which to test latitudinal (and temperature and depth) shifts in habitat ranges of calcifying organisms. Both the …

Go to article

Influence Of Extreme Storm Events On West Florida Shelf Cdom Distributions, Robyn N. Conmy, Paula G. Coble, Jennifer P. Cannizzaro, Cynthia A. Heil Nov 2009

Influence Of Extreme Storm Events On West Florida Shelf Cdom Distributions, Robyn N. Conmy, Paula G. Coble, Jennifer P. Cannizzaro, Cynthia A. Heil

Marine Science Faculty Publications

Colored Dissolved Organic Matter (CDOM) distribution and signatures provide vital information about the amount and composition of organic material in aquatic environments. This information is critical for deciphering the sources and biogeochemical pathways of organic carbon, and thus vital to the understanding of carbon cycling and budgets. Waters of the West Florida Shelf are heavily influenced by many river systems on Florida's Gulf Coast that, to the first order, control CDOM distributions on the shelf. Three storm events during 2004 and 2005 (Hurricane Charley, Hurricane Wilma, and a Winter Storm) profoundly altered the typical distribution of CDOM fluorescence and absorption …

Go to article

Low-Frequency Exchange Of Mass Between Ocean Basins, Don P. Chambers, Josh K. Willis Nov 2009

Low-Frequency Exchange Of Mass Between Ocean Basins, Don P. Chambers, Josh K. Willis

Marine Science Faculty Publications

We examine the Gravity Recovery and Climate Experiment (GRACE) data and output from an ocean model to quantify mass fluctuations for the Pacific, Atlantic, and Indian Ocean basins from August 2002 until December 2008. The monthly spatial mean is removed to study interbasin mass exchange. We find a seasonal exchange of mass between the Atlantic and Pacific that is similar to one documented previously, although the amplitude observed by GRACE is about 20% lower than that simulated by an ocean model. There are also significant fluctuations with periods longer than 1 year. We find large interannual exchanges in 2005 and …

Go to article

Detecting Marine Hazardous Substances And Organisms: Sensors For Pollutants, Toxins, And Pathogens, O. Zielinski, J. A. Busch, A. D. Cembella, Kendra L. Daly, J. Engelbrektsson, A. K. Hannides, H. Schmidt Sep 2009

Detecting Marine Hazardous Substances And Organisms: Sensors For Pollutants, Toxins, And Pathogens, O. Zielinski, J. A. Busch, A. D. Cembella, Kendra L. Daly, J. Engelbrektsson, A. K. Hannides, H. Schmidt

Marine Science Faculty Publications

Marine environments are influenced by a wide diversity of anthropogenic and natural substances and organisms that may have adverse effects on human health and ecosystems. Real-time measurements of pollutants, toxins, and pathogens across a range of spatial scales are required to adequately monitor these hazards, manage the consequences, and to understand the processes governing their magnitude and distribution. Significant technological advancements have been made in recent years for the detection and analysis of such marine hazards. In particular, sensors deployed on a variety of mobile and fixed-point observing platforms provide a valuable means to assess hazards. In this review, we …

Go to article

Mean Dynamic Topography Of The Ocean Derived From Satellite And Drifting Buoy Data Using Three Different Techniques, Nikolai Maximenko, Peter Niiler, Marie-Helene Rio, Oleg Melnichenko, Luca Centurioni, Boris Galperin, Don. P. Chambers, Victor Zlotnicki Sep 2009

Mean Dynamic Topography Of The Ocean Derived From Satellite And Drifting Buoy Data Using Three Different Techniques, Nikolai Maximenko, Peter Niiler, Marie-Helene Rio, Oleg Melnichenko, Luca Centurioni, Boris Galperin, Don. P. Chambers, Victor Zlotnicki

Marine Science Faculty Publications

Presented here are three mean dynamic topography maps derived with different methodologies. The first method combines sea level observed by the high-accuracy satellite radar altimetry with the geoid model of the Gravity Recovery and Climate Experiment (GRACE), which has recently measured the earth’s gravity with unprecedented spatial resolution and accuracy. The second one synthesizes near-surface velocities from a network of ocean drifters, hydrographic profiles, and ocean winds sorted according to the horizontal scales. In the third method, these global datasets are used in the context of the ocean surface momentum balance. The second and third methods are used to improve …

Go to article

Evaluation Of Groundwater Storage Monitoring With The Grace Satellite: Case Study High Plains Aquifer, Central United States, Gil Strassberg, Bridget Scanlon, D. Chambers May 2009

Evaluation Of Groundwater Storage Monitoring With The Grace Satellite: Case Study High Plains Aquifer, Central United States, Gil Strassberg, Bridget Scanlon, D. Chambers

Marine Science Faculty Publications

Water scarcity is a critical issue in semiarid regions; however, regional groundwater monitoring is extremely limited. This study evaluates the ability of the GRACE satellites to monitor groundwater storage in the semiarid High Plains aquifer, United States (450,000 km2 area), which is subjected to intense irrigation. GRACE-derived terrestrial water storage (TWS) is highly correlated with the sum of soil moisture (SM) and groundwater storage (GWS) (R = 0.96 for in situ measured SM from 78 stations and R = 0.95 for simulated SM with the Noah land surface model with root-mean-square difference of 38 mm and 36 mm, …

Go to article

Fish Effects On Ocean Current Observations In The Cariaco Basin, Jyotika I. Virmani, Robert H. Weisberg Mar 2009

Fish Effects On Ocean Current Observations In The Cariaco Basin, Jyotika I. Virmani, Robert H. Weisberg

Marine Science Faculty Publications

Multiple years of moored current meter observations from the Cariaco Basin show low‐frequency variations along with near‐inertial waves and further imply the persistent diurnal movement of fish species known to populate the basin. In agreement with short‐term observations from 1979, the more recent observations with acoustic Doppler current profilers provide evidence of the multidecadal presence and behavior of these species. An unwanted corollary, however, is a bias in both the vertical and horizontal components of velocity due to the fish movements. Removal of this fish bias results in large data loss (approximately 72%); however, an interpolated, non‐biased data set is …

Go to article

The Surface Circulation Of The Caribbean Sea And The Gulf Of Mexico As Inferred From Satellite Altimetry, Aida Alvera-Azcarate, Alexander Barth, Robert H. Weisberg Mar 2009

The Surface Circulation Of The Caribbean Sea And The Gulf Of Mexico As Inferred From Satellite Altimetry, Aida Alvera-Azcarate, Alexander Barth, Robert H. Weisberg

Marine Science Faculty Publications

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 …

Go to article

Grace-Based Estimates Of Terrestrial Freshwater Discharge From Basin To Continental Scales, Tajdarul H. Syed, James S. Famiglietti, Don Chambers Feb 2009

Grace-Based Estimates Of Terrestrial Freshwater Discharge From Basin To Continental Scales, Tajdarul H. Syed, James S. Famiglietti, Don Chambers

Marine Science Faculty Publications

In this study, new estimates of monthly freshwater discharge from continents, drainage regions, and global land for the period of 2003–05 are presented. The method uses observed terrestrial water storage change estimates from the Gravity Recovery and Climate Experiment (GRACE) and reanalysis-based atmospheric moisture divergence and precipitable water tendency in a coupled land–atmosphere water mass balance. The estimates of freshwater discharge are analyzed within the context of global climate and compared with previously published estimates. Annual cycles of observed streamflow exhibit stronger correlations with the computed discharge compared to those with precipitation minus evapotranspiration (P − E) in …

Go to article

Dynamically Constrained Ensemble Perturbations: Application To Tides On The West Florida Shelf, Alexander Barth, Aida Alvera-Azcarate, J. M. Beckers, Robert H. Weisberg, L. Vandenbulcke, F. Lenartz, M. Rixen Jan 2009

Dynamically Constrained Ensemble Perturbations: Application To Tides On The West Florida Shelf, Alexander Barth, Aida Alvera-Azcarate, J. M. Beckers, Robert H. Weisberg, L. Vandenbulcke, F. Lenartz, M. Rixen

Marine Science Faculty Publications

A method is presented to create an ensemble of perturbations that satisfies linear dynamical constraints. A cost function is formulated defining the probability of each perturbation. It is shown that the perturbations created with this approach take the land-sea mask into account in a similar way as variational analysis techniques. The impact of the land-sea mask is illustrated with an idealized configuration of a barrier island. Perturbations with a spatially variable correlation length can be also created by this approach. The method is applied to a realistic configuration of the West Florida Shelf to create perturbations of the M2 tidal …

Go to article

Hurricane Storm Surge Simulations Comparing Three-Dimensional With Two-Dimensional Formulations Based On An Ivan-Like Storm Over The Tampa Bay, Florida Region, Robert H. Weisberg, Lianyuan Zheng Dec 2008

Hurricane Storm Surge Simulations Comparing Three-Dimensional With Two-Dimensional Formulations Based On An Ivan-Like Storm Over The Tampa Bay, Florida Region, Robert H. Weisberg, Lianyuan Zheng

Marine Science Faculty Publications

We provide a dynamics‐based comparison on the results from three‐dimensional and two‐dimensional simulations of hurricane storm surge. We begin with the question, What may have occurred in the Tampa Bay, Florida vicinity had Hurricane Ivan made landfall there instead of at the border between Alabama and Florida? This question is explored using a three‐dimensional, primitive equation, finite volume coastal ocean model. The results show that storm surges are potentially disastrous for the Tampa Bay area, especially for landfalls located to the north of the bay mouth. The worst case among the simulations considered is for landfall at Tarpon Springs, such …

Go to article

Si Cycle In The Cariaco Basin, Venezuela: Seasonal Variability In Silicate Availability And The Si:C:N Composition Of Sinking Particles, Robert C. Thunell, Claudia Benitez-Nelson, Frank E. Muller-Karger, Laura Lorenzoni, Mary Scranton, Ramon Varela, Yrene Astor, Kent A. Fanning Dec 2008

Si Cycle In The Cariaco Basin, Venezuela: Seasonal Variability In Silicate Availability And The Si:C:N Composition Of Sinking Particles, Robert C. Thunell, Claudia Benitez-Nelson, Frank E. Muller-Karger, Laura Lorenzoni, Mary Scranton, Ramon Varela, Yrene Astor, Kent A. Fanning

Marine Science Faculty Publications

A 9‐year time series of water column and sediment trap measurements was used to examine silicon cycling within the anoxic Cariaco Basin. The dynamic hydrographic regime within Cariaco Basin results in strong seasonal changes in nutrient availability and the Si:C:N of sinking particles. Upwelling in early winter injects silicic acid (Si(OH)4= ) and nitrate (NO3−) rich waters into the photic zone which stimulates primary production and results in opal fluxes in excess of 4 mmol Si m−2 d−1. However, even during upwelling, surface waters tend to be depleted (<1 μM) in …

Go to article

Analysis Of Large-Scale Ocean Bottom Pressure Variability In The North Pacific, Don P. Chambers, Josh K. Willis Nov 2008

Analysis Of Large-Scale Ocean Bottom Pressure Variability In The North Pacific, Don P. Chambers, Josh K. Willis

Marine Science Faculty Publications

[1] We use the leading empirical orthogonal functions (EOFs) of ocean bottom pressure (OBP) derived from an ocean model and the technique of EOF reconstruction to reduce noise in the large-scale OBP variations derived from the Gravity Recovery and Climate Experiment (GRACE). The subsequent OBP variations from the model and GRACE are then examined in the North Pacific between January 2003 and May 2007. Although annual and semiannual variations are similar, GRACE observes large interannual fluctuations poleward of 30°, where OBP increases from a low of nearly 3 cm below normal in early 2003 to normal throughout 2004 and 2005, …

Go to article

Grace Observes Small-Scale Mass Loss In Greenland, B. Wouters, D. Chambers, E.J. O. Schrama Oct 2008

Grace Observes Small-Scale Mass Loss In Greenland, B. Wouters, D. Chambers, E.J. O. Schrama

Marine Science Faculty Publications

Using satellite gravity data between February 2003 and January 2008, we examine changes in Greenland's mass distribution on a regional scale. During this period, Greenland lost mass at a mean rate of 179 ± 25 Gt/yr, equivalent to a global mean sea level change of 0.5 ± 0.1 mm/yr. Rates increase over time, suggesting an acceleration of the mass loss, driven by mass loss during summer. The largest mass losses occurred along the southeastern and northwestern coast in the summers of 2005 and 2007, when the ice sheet lost 279 Gt and 328 Gt of ice respectively within 2 months. …

Go to article

Estimating Geocenter Variations From A Combination Of Grace And Ocean Model Output, Sean Swenson, D. Chambers, John Wahr Aug 2008

Estimating Geocenter Variations From A Combination Of Grace And Ocean Model Output, Sean Swenson, D. Chambers, John Wahr

Marine Science Faculty Publications

In this study, we estimate a time series of geocenter anomalies from a combination of data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission and the output from ocean models. A matrix equation is derived relating total geocenter variations to the GRACE coefficients of degrees two and higher and to the oceanic component of the degree one coefficients. We estimate the oceanic component from t wo state-of-the-art ocean models. Results are compared to independent estimates of geocenter derived from other satellite data, such as satellite laser ranging and GPS. Finally, we compute degree one coefficients that are consistent …

Go to article

Assimilation Of High-Frequency Radar Currents In A Nested Model Of The West Florida Shelf, Alexander Barth, Aida Alvera-Azcarate, Robert H. Weisberg Aug 2008

Assimilation Of High-Frequency Radar Currents In A Nested Model Of The West Florida Shelf, Alexander Barth, Aida Alvera-Azcarate, Robert H. Weisberg

Marine Science Faculty Publications

High‐frequency radar currents are assimilated in a West Florida Shelf (WFS) model based on the Regional Ocean Model System (ROMS), which is nested in the Atlantic Hybrid Coordinate Ocean Model (HYCOM) for the purpose of including both local and deep‐ocean forcing, particularly the Gulf of Mexico Loop Current. Tides are not included in this model. An ensemble simulation of the WFS model is carried out under different wind‐forcings in order to estimate the error covariance of the model state vector and the covariance between ocean currents and winds. Radial currents measured by high‐frequency radar antennas near Saint Petersburg and Venice, …

Go to article

Assessing The Globally Averaged Sea Level Budget On Seasonal To Interannual Timescales, Josh K. Willis, D. Chambers, R Steven Nerem Jun 2008

Assessing The Globally Averaged Sea Level Budget On Seasonal To Interannual Timescales, Josh K. Willis, D. Chambers, R Steven Nerem

Marine Science Faculty Publications

Analysis of ocean temperature and salinity data from profiling floats along with satellite measurements of sea surface height and the time variable gravity field are used to investigate the causes of global mean sea level rise between mid-2003 and mid-2007. The observed interannual and seasonal fluctuations in sea level can be explained as the sum of a mass component and a steric (or density related) component to within the error bounds of each observing system. During most of 2005, seasonally adjusted sea level was approximately 5 mm higher than in 2004 owing primarily to a sudden increase in ocean mass …

Go to article

A Nested Model Study Of The Loop Current Generated Variability And Its Impact On The West Florida Shelf, Alexander Barth, Aida Alvera-Azcarate, Robert H. Weisberg May 2008

A Nested Model Study Of The Loop Current Generated Variability And Its Impact On The West Florida Shelf, Alexander Barth, Aida Alvera-Azcarate, Robert H. Weisberg

Marine Science Faculty Publications

A West Florida Shelf model based on the Regional Ocean Modeling System (ROMS) is nested in the North Atlantic Hybrid Coordinate Ocean Model (NAT HYCOM). The focus of this work is the study of the impact of the Loop Current on the West Florida Shelf. In order to assess the model's accuracy, it is compared quantitatively to in situ temperature and velocity measurements on the shelf. A series of sensitivity experiments are conducted to determine the appropriate wind forcing, sea surface temperature relaxation, and mixing scheme. by the inclusion of the Loop Current, we are able to study the propagation …

Go to article

An Optical Model For Heat And Salt Budget Estimation For Shallow Seas, Hari Warrior, Kendall L. Carder Dec 2007

An Optical Model For Heat And Salt Budget Estimation For Shallow Seas, Hari Warrior, Kendall L. Carder

Marine Science Faculty Publications

The effects of the underwater light field on heat-budget calculations for shallow waters are developed and applied for the region of Bahamas. Most of the general circulation models use a simplified heat budget scheme based on Jerlov water types, and do not account for optical bottom effects. by optical bottom effect, we mean the bottom absorption and reflection of the short-wave radiation, which in turn affects the thermal stratification and heat exchange with the atmosphere. In this paper, this optical bottom effect is added to a 3D turbulence model (a 1D model called GOTM is coupled to a 3D model …

Go to article

A High Resolution Satellite-Only Grace-Based Mean Dynamic Topography Of The South Atlantic Ocean, Marcio L. Vianna, Viviane V. Menezes, D. Chambers Dec 2007

A High Resolution Satellite-Only Grace-Based Mean Dynamic Topography Of The South Atlantic Ocean, Marcio L. Vianna, Viviane V. Menezes, D. Chambers

Marine Science Faculty Publications

A new filtering method based on Singular Spectrum Analysis has been devised to extract high resolution (0.25° × 0.25° grid) satellite-only Mean Dynamic Ocean Topography(MDT) constructed by differencing of the GGM02 GRACE Gravity Model from the GSFCMSS00 Mean Sea Surface. This data-adaptive interpolation-type filter is adequate for the finite domain MDT processing since it minimizes smoothing and does not lose boundary points. It is applied to the computation of two new MDTs and MDT-derived mean geostrophic circulation maps of the South Atlantic region from 15°N to 50°S. Advantages of these new maps are clarified when contrasted with the Rio-2005, Chambers-Zlotnicki-2004 …

Go to article

First Prev Next Last