Steven F. Dimarco

• PhD, Physics, UT - Dallas
• Professor (Full) at Texas A&M University

A previously uninvestigated necking‐down region in the Gulf of Mexico, associated with the Loop Current eddy (LCE) separations is defined by the 8–16 days variance below the Loop Current system (LCS) around 88.5°W, using an Ocean‐Atmosphere Coupled Regional‐Community Earth System Model (R‐CESM) 9‐year nature run, which reveals the mechanisms of Loo...

Ocean buoyancy gliders provide a comprehensive view of the water column, offering more than simply a snapshot of a single moment in time or space. In this study, we applied the established machine learning method, k‐means clustering, to a glider dataset collected in the summer of 2015 in the northern Gulf of Mexico. Clustering analysis of chromopho...

We report the preliminary results of the international MASTR (Mini-Adaptive Sampling Test-Run) Experiment of the UGOS (Understanding the Gulf Ocean Systems) Program, which simultaneously deployed multiple autonomous measurement platforms (i.e., ocean buoyancy gliders, subsurface floats, surface drifters) and high-frequency coastal radar in the Deep...

An Ocean-Atmosphere Coupled Regional-Community Earth System Model (R-CESM) 9-year nature run is used to reveal the mechanisms of Loop Current (LC) deep dynamics. Compared to the in-situ observations, the R-CESM can capture the major features of Loop Current Eddy (LCE) shedding events in upper and lower layers, and its thermal structure within 0.5 °...

Considering the benefits of understanding the circulation patterns of the shelf, it is not surprising that there are numerous studies of the Texas Shelf circulation patterns. Given that previous studies were focused on the low-frequency variability of the circulation which is upcoast (northeast flow) in the summer and downcoast (southwest flow) esp...

Dissolved oxygen and current observations from a cabled ocean observatory in the Sea of Oman show that the annual recurrence of coastal hypoxia, defined as dissolved oxygen concentrations ≤63 μM, is associated with the seasonal cycle of local monsoon winds. The observations represent the first long-term (5+ years) continuous moored observations off...

Intense rainfall from tropical cyclones has the potential to induce coastal acidification, which will become more common and severe as climate change continues. We collected carbonate chemistry samples from Galveston Bay, Texas before and after Hurricane Harvey in 2017 and 2018. Here, we show ecosystem level acidification and calcium carbonate unde...

Hurricane Harvey deposited over 90 billion cubic meters of rainwater over central Texas, USA, during late August/early September 2017. During four cruises (June, August, September and November 2017) we observed changes in hydrography, nutrient and oxygen concentrations in Texas coastal waters. Despite intense terrestrial runoff, nutrient supply to...

This study investigates the resonated diurnal impact of the surface wind forcing from several atmospheric wind products, including CCMP (Cross-Calibrated Multi-Platform), ERA Interim, NCEP-2 (NCEP-DOE AMIP-II Reanalysis), MERRA (Modern-Era Retrospective analysis for Research and Application), NARR (Northern American Regional Reanalysis) and NAM (No...

Loop Current Eddies (LCEs) are warm-core, anticyclonic rings that shed from the Loop Current and migrate westward providing kinetic and potential energy to the Gulf of Mexico (GoM). Typically, LCEs dissipate through interaction with the western shelf slope, other mesoscale eddies, and diapycnal mixing. Here, we explore a case where a LCE, Eddy Pose...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

We report an experimental investigation of turbulence in bubble plumes released in unstratified quiescent water. The focus is to study the detailed turbulent statistics and the budget terms in the equations of turbulent kinetic energy (TKE), particularly about their distributions in the radial direction of bubble plumes compared to those in the sin...

Plain Language Summary Natural bubble seepage in the deep ocean is increasingly observed by shipboard surveys using sonars. These acoustic signals of these bubble flares are observed high into the ocean water column, raising the question of what the vertical distribution of natural seep gases, including methane, originating at natural seeps may be...

The AdjustaDepth TechnoEconomic Analysis was prepared by Mark E. Capron PE, Co-PI, under the direction of Kelly Lucas, PhD, PI and submitted April 3, 2019 to U.S. Department of Energy ARPA-E under Phase 1 Contract DE-AR0000916. Its 33 tabs present the cost and yield projections for growing Gracilaria tikvahiae in the Gulf of Mexico. It can be adapt...

Approximately 380,000 underway measurements of sea surface salinity, temperature, and carbon dioxide (CO2) in the Gulf of Mexico (GoM) were compiled from the Surface Ocean CO2 Atlas (SOCAT) to provide a comprehensive observational analysis of spatiotemporal CO2 dynamics from 1996 to 2017. An empirical orthogonal function (EOF) was used to derive th...

We present an experimental study to investigate the impact of bubble size on behavior of bubble plumes from the integral point of view. Two distinct types of bubble plume were generated under the same volumetric gas flow rate: many small bubbles using an air-stone diffuser and a few large bubbles using a single-orifice diffuser. Using Particle Imag...

Stratification has been proved to be essential to the development and sustainment of bottom hypoxia off the Texas-Louisiana shelf. Observations indicate that bottom hypoxia does not always arise under strong stratification, especially in spring/winter season when the strong stratification is transient. A simple oxygen model is coupled with a high-r...

On July 25, 2016, turbid water and dead corals, sponges and other invertebrates were discovered at the East Bank (EB) of the Flower Garden Banks (FGB) National Marine Sanctuary. Mortality was spread over 0.06 km², with up to 80% coral mortality reported in some areas. Within days, response efforts were underway to investigate the potential mechanis...

Coastal ocean productivity is often dependent on riverine sources of nutrients, yet it can be difficult to determine how far the influence of the river extends. The northern Gulf of Mexico (GOM) receives freshwater and nutrients discharged mainly from the Mississippi and Atchafalaya Rivers. We used nutrient/salinity relationships to (i) differentia...

The coastal Gulf of Mexico (GOM) and coastal sea off the Korean Peninsula (CSK) both suffer from human-induced eutrophication. We used a nitrogen (N) mass balance model in two different regions with different nitrogen input sources to estimate organic carbon fluxes and predict future carbon fluxes under different model scenarios. The coastal GOM re...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

Over the past decade, measurements from the climate-oriented ocean observing system have been key to advancing the understanding of extreme weather events that originate and intensify over the ocean, such as tropical cyclones (TCs) and extratropical bomb cyclones (ECs). In order to foster further advancements to predict and better understand these...

The extent of hypoxia on the Louisiana shelf has been measured during July since 1985. The measured area was assumed to represent the seasonal maximum each year and was related to the Mississippi‐Atchafalaya riverine May NO2+3 loading and May–June total nitrogen loading, for planning management strategies. In this study, we analyze 25 years of simu...

The coastal Gulf of Mexico (GOM) and Coastal Sea off Korea (CSK) both suffer from human-induced eutrophication. We used a N-mass balance model in two different regions with different nitrogen input sources to estimate organic carbon fluxes and predict future carbon fluxes under different model scenarios. The coastal GOM receives nitrogen predominan...

AdjustaDepth Project was funded by the U.S. Department of Energy Advanced Research Projects Agency - Energy to design an artificial reef system for growing and harvesting seaweed for advanced sustainable biofuels. The team discovered that the system grows more seaweed per hectare when it is part of a complete ecosystem with shellfish, finfish, and...

Fugro was contracted in 2014 by Shell to provide a Fugro Wavescan Buoy system to support the life of field of the Stones development in the Gulf of Mexico. The companies have worked together to expand the monitoring system of the Shell Alcyone buoy system from a tool designed to satisfying regulatory compliance into a scientific platform for deep o...

Harvey entered the Gulf of Mexico as a tropical depression on 23 August 2017; two days later it had strengthened to a category 1 hurricane. Over the following 30 hr Harvey rapidly intensified, reaching the Texas Bight as a category 3 storm. This intensification continued while Harvey crossed the shelf, making landfall as a category 4 storm 60 km ea...

The U.S. Department of Energy Advanced Research Projects Agency for Energy (ARPA-E) funded our team to grow seaweed-for-biofuel inexpensively and sustainably. We also found a way to feed the world with shellfish and finfish grown on huge floating flexible reefs without using fishmeal and while simultaneously growing seaweed. I'm Kelly Lucas, Direct...

The BP-operated Deepwater Horizon (DWH) oil rig blowout in April 2010 led to the release of about 700,000 tons of crude oil and 250,000 tons of gas into the Gulf of Mexico (GoM) before it was capped. It also led, tragically, to 11 deaths and 16 injuries to people on the rig. This was the first deep, subsurface ocean spill in offshore oil exploratio...

The US Department of Energy Advanced Research Projects Agency-Energy (ARPA-E) MacroAlgae Research Inspiring Novel Energy Research (MARINER) program is encouraging technologies for the sustainable harvest of large funding research of macroalgae for biofuels at less than $80 per dry metric ton (DMT). The Ocean Forests team, led by the University of S...

This paper describes the "SeaweedPaddock" system to profitably grow and harvest open-ocean Sargassum sp. as a sustainable source of macroalgal biomass and biofuel. The US Department of Energy Advanced Research Projects Agency-Energy (ARPA-E) initiated the MacroAlgae Research Inspiring Novel Energy Research (MARINER) program to develop technologies...

Coastal ocean observing systems are used throughout the world to provide sustained, real-time observations of the coastal ocean environment, to address regional issues and to provide local context to global environmental variability. However, the level of sophistication in these systems is not equal globally mainly due to resource limitations. Over...

We report seasonal water column carbonate chemistry data collected over a three-year period (late 2013 to 2016) at Flower Garden Banks National Marine Sanctuary (FGBNMS) located on the subtropical shelf edge of the northwestern Gulf of Mexico. The FGBNMS hosts the northernmost tropical coral species in the contiguous United States, with over 50% li...

Seafloor sediment resuspension events of different scales and magnitudes and the resulting deep (>1,000 m) benthic nepheloid layers were investigated in the northern Gulf of Mexico during Fall 2012 to Summer 2013. Time-series data of size-specific in-situ settling speeds of marine snow in the benthic nepheloid layer (moored flux cameras), particle...

A long-term mooring array deployed in the northern Gulf of Mexico is used to analyze energy exchange between internal waves and low-frequency flows. In the subthermocline (245-450 m), there is a noticeable net energy transfer from low-frequency flows, defined as having a period longer than six inertial periods, to internal waves. The magnitude of e...

Time series data of size-specific in-situ settling speeds of marine snow obtained by moored flux cameras, particle size distributions from a lowered profiling camera, current speed and directions from moored ADCP and single point current meters are combined with stacked time series sediment trap flux data to identify resuspension events of differen...

While the exchange of water through Yucatan Strait is reasonably well known, the age of the deep water in both the Caribbean Sea and Gulf of Mexico is not. We recently measured the radiocarbon ( ¹⁴ C) concentrations in deep water in the Gulf of Mexico from a line of stations along 90°30′W. The mean apparent age of water below 900 m, the depth of th...

The Gulf of Mexico Coastal Hypoxia Glider Experiment was designed to assess the feasibility of using ocean glider technology in the coastal hypoxic zone of the northern Gulf of Mexico in Summer/Fall 2014. The objectives were (1) to coordinate and operate multiple autonomous buoyancy ocean gliders in depths less than 50 m and (2) to determine how cl...

The tropical Atlantic basin is one of seven global regions where tropical cyclones (TCs) commonly originate, intensify, and affect highly populated coastal areas. Under appropriate atmospheric conditions, TC intensification can be linked to upper-ocean properties. Errors in Atlantic TC intensification forecasts have not been significantly reduced d...

MetOcean is the collection, processing, and analysis of meteorological and oceanographic environmental parameters that are relevant to the design of offshore oil and gas exploration, drilling, and production structures and in the near real-time reporting of environmental parameters that may influence offshore operations or may be used in oil spill...

This study incorporates observations from Array of Real-time Geostrophic Oceanography (ARGO) floats and surface drifters to identify seasonal circulation patterns at the surface, 1000 m, 1500 m, and 2000 m in the northwest Indian Ocean, and quantify velocities associated with them. A skill comparison of the Simple Ocean Data Assimilation (SODA) rea...

We developed a Kemp’s ridley (Lepidochelys kempii) stock assessment model to evaluate the relative contributions of conservation efforts and other factors toward this critically endangered species’ recovery. The Kemp’s ridley demographic model developed by the Turtle Expert Working Group (TEWG) in 1998 and 2000 and updated for the binational recove...

The Texas coast represents an area of interest for a wide variety of stakeholders, including the oil industry (for both, exploration and operation purposes), fisheries and living resource management, ecosystem, coastal hazard mitigation and planning, and ocean and coastal education. For more than twenty years, the Texas coast has relied on the Texa...

The eye of Hurricane Isaac passed through the center of an array of six deepwater water-column current meter moorings deployed in the northern Gulf of Mexico. The trajectory of the hurricane provided for a unique opportunity to quantify differences in the full water-column oceanic response to a hurricane to the left and right of the hurricane traje...

The Mississippi and Atchafalaya Rivers are the primary riverine sources of freshwater and nutrients discharged to the Gulf of Mexico (GOM). This research focuses on how to differentiate between water from the Mississippi and Atchafalaya rivers, using major nutrient elements such as nitrogen (N), phosphorus (P), and silicon (Si). Total nitrogen (NO3...

A 25-km streak of CF 3SF5 was released on an isopycnal surface approximately 1100 m deep, and 150 m above the bottom, along the continental slope of the northern Gulf of Mexico, to study stirring and mixing of a passive tracer. The location and depth of the release were near those of the deep hydrocarbon plume resulting from the 2010 Deepwater Hori...

An integrated observational field effort that makes simultaneous and collocated measurements of turbulence and fine-scale parameters has been conducted near the Deepwater Horizon oil spill site in the northern Gulf of Mexico (GOM). Full water column profiles are collected across the continental slope in July 2013. The observational results suggest...

Moored ADCP data collected in the northern Gulf of Mexico are analyzed to examine near-inertial internal waves and their contribution to subthermocline diapycnal mixing based on a finescale parameterization of deep ocean mixing. The focus of the study is on the impact of near-inertial internal waves generated by an extreme weather eventthat is, Hur...

Most commercially, important food fishes in the tropics reproduce in spawning aggregations, which serve to replenish their populations via larval dispersal. Dispersal pathways are not well understood. This study examines the dispersal hypothesis assumed for most dispersal modeling studies, i.e. that prevailing currents transport freshly released eg...

We investigate distributions of dissolved oxygen over the Texas-Louisiana shelf using spatially highly resolved observations in combination with a regional circulation model with simple oxygen dynamics. The observations were collected using a towed, undulating CTD during the Mechanisms Controlling Hypoxia (MCH) program. Mid-water oxygen minimum lay...

The so called “Smooth Orthogonal Decomposition” technique, developed in the nonlinear vibrations and fatigue community, is applied to an oceanographic dataset. This decomposition technique overcomes some limitations of the Proper Orthogonal Decomposition technique by identifying modes which behave smoothly in time and thus being sensitive to both v...

Texas has established an operational system that provides observations of wind and currents to the State On-Scene Coordinator. The Texas Automated Buoy System (TABS) began in 1994 with five current meter buoys. Buoys measure current velocity 2m below the surface and transmit data on a regular schedule via satellite communications. Most buoys measur...

The 2012 revision of the Gulf of Mexico Monitoring Implementation Plan included the need to hold a workshop to determine the optimal glider design and glider monitoring strategy for temporal/spatial coverage that would complement ship surveys and observing systems. On 17-19 April of 2013 the workshop was held as part of the Forum for Gulf of Me...

Investigating Hydrographic Variability in the Western Gulf of Mexico Using Autonomous Underwater Vehicles R. Mullins-Perry1, S. F. DiMarco1, J. Walpert2, K. Dreger, A. Knap2, 1Department of Oceanography, Texas A&M University, College Station, TX 77843, USA 2Geochemical and Environmental Research Group (GERG), Texas A&M University, College Statio...

Autonomous underwater vehicles (AUVs) are emerging tools in the ocean observing community and have been proven as critical components for the future design and implementation of ocean observing networks. Subsea gliders, a class of AUVs, played a prominent role in assessing the post-spill ocean environment following the 2010 Deepwater Horizon event...

An ocean observatory—consisting of a real-time, cabled system in the Sea of Oman and an internally-recording, autonomous mooring system upgraded in 2010 to a cabled system in the northern Arabian Sea—was installed in 2005. Lighthouse R & D Enterprises designed and installed and now operates and maintains the systems with permission from the Oman Mi...

Rising CO2 concentration in the atmosphere, global climate change, and the sustainability of the Earth's biosphere are great societal concerns for the 21st century. Global climate change has, in part, resulted in a higher frequency of flooding events, which allow for greater exchange between soil/plant litter and aquatic carbon pools. Here we demon...

Management of coastal resources requires extended range forecasts. For example, presently statistical information is used at seasonal scales for predicting conditions related to biological activity and thus hazards to human activity along the coastlines. As part of the Earth System Prediction Capability efforts, numerical forecast accuracy impact t...

The hypoxic region in the northern Gulf of Mexico, one of the largest man-made hypoxic zones in the world, has received extensive scientific study and management interest. A previous statistical study has concluded that in addition to anthropogenic nitrogen loading, the observed hypoxic extent is correlated to the duration of upwelling favorable (w...

Autonomous underwater vehicles (AUVs) are emerging tools in the ocean observing community and have been recently considered critical components for the future design and implementation of ocean observing networks in the Gulf of Mexico. The use of gliders will be important for complementing existing observatories, such as the Texas Automated Buoy Sy...

A high-resolution coastal model is used to investigate the transport, filling and flushing times of the freshwater introduced from the Mississippi and Atchafalaya Rivers on the Texas-Louisiana Shelf. The model is forced with realistic forcing, and is nested within hindcasts from the HYCOM operational model. The Mississippi and Atchafalaya discharge...

To investigate the potential for mollusks to serve as proxies for benthic respiration and hypoxia in the Gulf of Mexico (GOM), five gastropod (Conus austini Rehder and Abbott, 1951 and Strombus alatus Gmelin, 1791) and five bivalve (Pteria colymbus Röding, 1798 and Spondylus calcifer Carpenter, 1857) shells, from six Texas-Louisiana shelf localitie...

In recent years, there have been several major initiatives to install fiber-optic cabled ocean observatories in the United States, Canada, Japan, and Europe. Lighthouse has operated a fiber-optic cabled ocean observing system off the northern coast of the Sultanate of Oman for seven years: the Lighthouse Ocean Research Initiative (LORI) I. In early...

An ocean observatory—consisting of a real-time, cabled array in the Sea of Oman and an internally recording, autonomous mooring array recently upgraded to a cabled array in the northern Arabian Sea—celebrated more than 2500 days of continuous operation in July 2012. The observatory, which measures a range of properties, such as water current veloci...

Seasonal hypoxia of the northern Gulf of Mexico has been observed for more than 25 years. It is generally accepted that the variation in the areal extent of hypoxia is determined by changes in nutrient addition from the Mississippi River. In this study, we investigate the statistical relation between the hypoxic area and a new variable, the duratio...

Lighthouse R&D Enterprises, Inc. installed the first cabled ocean observatory system for the Sultanate of Oman's Ministry of Agriculture and Fisheries Wealth in mid-2005 and a second cabled system in early 2010. The systems are designed to study a range of oceanic phenomena and provide a wealth of data to manage fisheries resources and recreational...

Hypoxic conditions in the coastal waters off Texas (USA) were observed since the late 1970s, but little is known about the causes of stratification that contribute to hypoxia formation. Typically, this hypoxia is attributed to downcoast (southwestward) advection of waters from the Mississippi–Atchafalaya River system. Here, we present evidence for...

We omitted an acknowledgment of funding in our letter. It should read: Acknowledgments This research was funded by the National Oceanic and Atmospheric Administration Center for Sponsored Coastal Ocean Research under contract number NA09NOS4780208. This article is contribution No.3188 of the Virginia Institute of Marine Science.