Physical Sciences and Mathematics Commons^™

Remote Internal Wave Forcing Of Regional Ocean Simulations Near The U.S. West Coast, Oladeji Q. Siyanbola, Maarten C. Buijsman, Audrey Delpech, Lionel Renault, Roy Barkan, Jay F. Shriver, Brian K. Arbic, James C. Mcwilliams

Faculty Publications

Low mode internal waves are able to propagate across ocean basins and modulate ocean dynamics thousands of kilometers away from their generation sites. In this study, the impact of remotely generated internal waves on the internal wave energetics near the U.S. West Coast is investigated with realistically forced regional ocean simulations. At the open boundaries, we impose high-frequency oceanic state variables obtained from a global ocean simulation with realistic atmospheric and astronomical tidal forcing. We use the Discrete Fourier Transform (DFT) technique in separating ingoing and outgoing internal tide energy fluxes at the open boundaries in order to quantify internal …

On The Spatial Variability Of The Mesoscale Sea Surface Height Wavenumber Spectra In The Atlantic Ocean, Xiaobiao Xu, Eric P. Chassignet, Alan J. Wallcraft, Brian K. Arbic, Maarten C. Buijsman, Miguel Solano

Faculty Publications

The wavenumber spectral slope of sea surface height (SSH) computed within the mesoscale range (70–250 km) from satellite altimetry exhibits a large spatial variability which, until now, has not been reproduced in numerical ocean models. This study documents the impacts of including internal tides, high-resolution bathymetry, and high-frequency atmospheric variability on the SSH wavenumber spectra in the Atlantic Ocean, using a series of 1/50° North and equatorial Atlantic simulations with a realistic representation of barotropic/baroclinic tides and mesoscale-to-submesoscale variability. The results show that the inclusion of internal tides does increase high frequency SSH variability (with clear peaks near 120 and …

Near-Inertial Wave Energetics Modulated By Background Flows In A Global Model Simulation, Keshav J. Raja, Maarten J. Buijsman, Jay F. Shriver, Brian K. Arbic, Oladeji Siyanbola

Faculty Publications

We study the generation, propagation, and dissipation of wind-generated near-inertial waves (NIWs) in a global 1/25° Hybrid Coordinate Ocean Model (HYCOM) simulation with realistic atmospheric forcing and background circulation during 30 days in May–June 2019. The time-mean near-inertial wind power input and depth-integrated energy balance terms are computed for the total fields and the fields decomposed into vertical modes to differentiate between the radiative and (locally) dissipative components of NIW energy. Only 30.3% of the near-inertial wind input projects onto the first five modes, whereas the sum of the NIW energy in the first five modes adds up to 58% …

Mid-Breton Sediment Diversion (Mbrsd) Assessment – Final Report, Jerry D. Wiggert, Brandy N. Armstrong, M. Kemal Cambazoglu, Sandeep Kalathupurath Kuttan

Faculty Publications

The purpose of this project is to provide managers at the Mississippi Department of Marine Resources (MDMR) with the scientific information needed to accurately address public concerns regarding the potential effects of the Louisiana Coastal Master Plan / Coastal Protection and Restoration Authority (CPRA) Mid-Breton Sediment Diversion (MBrSD) on the jurisdictional waters and resources of Mississippi. The stated design purpose of the MBrSD is to reconnect and re-establish the deltaic sediment deposition process between the Mississippi River and the Breton Sound Basin through a diversion that will deliver up to 75,000 cfs of sediment-laden freshwater. The report presented herein provides …

Heterogeneous Co2And Ch4Content Of Glacial Meltwater From The Greenland Ice Sheet And Implications For Subglacial Carbon Processes, Andrea J. Pain, Jonathan B. Martin, Ellen E. Martin, Åsa K. Rennermalm, Shaily Rahman

Faculty Publications

Accelerated melting of the Greenland Ice Sheet has increased freshwater delivery to the Arctic Ocean and amplified the need to understand the impact of Greenland Ice Sheet meltwater on Arctic greenhouse gas budgets. We evaluate subglacial discharge from the Greenland Ice Sheet for carbon dioxide (CO₂) and methane (CH₄) concentrations and δ¹³C values and use geochemical models to evaluate subglacial CH₄ and CO₂ sources and sinks. We compare discharge from southwest (a sub-catchment of the Isunnguata Glacier, sub-Isunnguata, and the Russell Glacier) and southern Greenland (Kiattut Sermiat). Meltwater CH₄ concentrations vary …

Prospects For Gulf Of Mexico Environmental Recovery And Restoration, Denis A. Wiesenburg, Bob Shipp, F. Joel Fodrie, Sean Powers, Julien Lartigue, Kelly M. Darnell, Melissa M. Baustian, Cam Ngo, John F. Valentine, Kateryna Wowk

Faculty Publications

Previous oil spills provide clear evidence that ecosystem restoration efforts are challenging, and recovery can take decades. Similar to the Ixtoc 1 well blowout in 1979, the Deepwater Horizon (DWH) oil spill was enormous both in volume of oil spilled and duration, resulting in environmental impacts from the deep ocean to the Gulf of Mexico coastline. Data collected during the National Resource Damage Assessment showed significant damage to coastal areas (especially marshes), marine organisms, and deep-sea habitat. Previous spills have shown that disparate regions recover at different rates, with especially long-term effects in salt marshes and deepsea habitat. Environmental recovery …

Accuracy Assessment Of Global Internal-Tide Models Using Satellite Altimetry, Loren Carrere, Brian K. Arbic, Brian Dushaw, Gary Egbert, Svetlana Erofeeva, Florent Lyard, Richard D. Ray, Clement Ubelmann, Edward Zaron, Zhongxiang Zhao, Jay F. Shriver, Maarten Cornelis Buijsman, Nicolas Picot

Faculty Publications

Altimeter measurements are corrected for several geophysical parameters in order to access ocean signals of interest, like mesoscale or sub-mesoscale variability. The ocean tide is one of the most critical corrections due to the amplitude of the tidal elevations and to the aliasing phenomena of high-frequency signals into the lower-frequency band, but the internal-tide signatures at the ocean surface are not yet corrected globally.

Internal tides can have a signature of several centimeters at the surface with wavelengths of about 50–250 km for the first mode and even smaller scales for higher-order modes. The goals of the upcoming Surface Water …

Destabilizing Effects On A Classic Tri-Trophic Oyster Reef Cascade, Virginia R. Schweiss, Chet F. Rakocinski

Faculty Publications

How interactions among multiple predators affect the stability of trophic cascades is a topic of special ecological interest. To examine factors affecting the stability of the classic tri-trophic oyster reef cascade within a different context, configurations of three predators, including the Gulf toadfish, Gulf stone crab, and oystershell mud crab, were manipulated together with either oyster shell or limestone gravel substrate within a multiple predator effects (MPE) experiment. Additionally, a complimentary set of trait-mediated-indirect interaction (TMII) experiments examined the inhibition of oyster consumption relative to mud-crab size and top predator identity in the absence of other cues and factors. The …

Monitoring 2019 Bonnet Carré Spillway Impacts - Final Report, J. Read Hendon, Jerry D. Wiggert, Jill Hendon

Faculty Publications

Due to the multiple and extended openings of the Bonnet Carré Spillway in 2019, the University of Southern Mississippi (USM) was tasked by the Mississippi Department of Marine Resources to conduct ecological sampling in the Mississippi Sound and adjacent waters. in an effort to better understand the impacts of the extensive freshwater diversion of Bonnet Carré Spillway operations on Mississippi's coastal and marine resources. The period of performance for this project was June 1, 2019, to August 31, 2019. This technical report summarizes the three months of weekly surveys and analyses, over June - August 2019, conducted by the University …

Sampling Density And Date Along With Species Selection Influence Spatial Representation Of Tree-Ring Reconstructions, Justin T. Maxwell, Grant L. Harley, Trevis J. Matheus, Brandon M. Strange, Kayla Van Aken, Tsun Fung Au, Joshua C. Bregy

Faculty Publications

© 2020 Royal Society of Chemistry. All rights reserved. Our understanding of the natural variability of hydroclimate before the instrumental period (ca. 1900 CE in the United States) is largely dependent on tree-ring-based reconstructions. Large-scale soil moisture reconstructions from a network of tree-ring chronologies have greatly improved our understanding of the spatial and temporal variability in hydroclimate conditions, particularly extremes of both drought and pluvial (wet) events. However, certain regions within these large-scale network reconstructions in the US are modeled by few tree-ring chronologies. Further, many of the chronologies currently publicly available on the International Tree-Ring Data Bank (ITRDB) were …

Long Lived Second Mode Internal Solitary Waves In The Andaman Sea, J.M. Magalhaes, J.C.B. Da Silva, Maarten C. Buijsman

Faculty Publications

Internal waves are density oscillations propagating along the ocean’s inner stratification, which are now acknowledged as a key constituent of the ocean’s dynamics. They usually result from barotropic tides, which flow over bottom topography, causing density oscillations to propagate along the pycnocline with a tidal frequency (i.e. internal tides). These large-scale waves propagate away from their forcing bathymetry and frequently disintegrate into nonlinear short-scale (higher-frequency) internal wave packets. Typically, short-scale internal wave observations in the ocean are associated with vertical structures (in the water column) of the lowest fundamental mode. Higher vertical modes have recently been documented as well, but …

The Importance Of Infrequent, High-Intensity Rainfall Events For Longleaf Pine (Pinus Palustris Mill.) Radial Growth And Implications For Dendroclimatic Research, Tyler J. Mitchell, Paul A. Knapp, Thomas W. Patterson

Faculty Publications

Tree-ring based precipitation reconstructions are beneficial in placing interannual variability in an historical context. However, absent specificity on what is being modeled (e.g., event type or rainfall intensity), similar rainfall totals inferred from reconstructions between different years imply similar conditions. Consequently, variability in specific precipitation event types or intensity can affect radial growth widths despite no changes in overall precipitation amount. Here, we use a longleaf pine latewood chronology to demonstrate how infrequent, intense (i.e., > 2.0 SD above mean) rainfall events (IREs), representing ~ 50% of total summer (July–September) precipitation amounts and 14.1% of rainfall events, principally determine interannual variability …

Statistical Comparisons Of Temperature Variance And Kinetic Energy In Global Ocean Models And Observations: Results From Mesoscale To Internal Wave Frequencies, Conrad A. Luecke, Brian K. Arbic, James G. Richman, Jay F. Shriver, Matthew H. Alford, Joseph K. Ansong, Steven L. Bassette, Maarten C. Buijsman, Dimitris Menemenlis, Robert B. Scott, Patrick G. Timko, Gunnar Voet, Alan J. Wallcraft, Luis Zamudio

Faculty Publications

©2020. American Geophysical Union. All Rights Reserved. Temperature variance and kinetic energy (KE) from two global simulations of the HYbrid Coordinate Ocean Model (HYCOM; 1/12° and 1/25°) and three global simulations of the Massachusetts Institute of Technology general circulation model (MITgcm; 1/12°, 1/24°, and 1/48°), all of which are forced by atmospheric fields and the astronomical tidal potential, are compared with temperature variance and KE from a database of about 2,000 moored historical observations (MHOs). The variances are computed across frequencies ranging from supertidal, dominated by the internal gravity wave continuum, to subtidal, dominated by currents and mesoscale eddies. The …

Changes In Regional Snowfall In Central North America (1961-2017): Mountain Versus Plains, Jiyang Zhang, Haochi Zheng, Xiaodong Zhang, Jeffrey Vanlooy

Faculty Publications

Long-term snowfall change offers insight for understanding climate change, managing water resources, and assessing climate model performance, especially at regional scales where topography plays an important role in shaping regional climate and water availability. In this study, we examined the changes of annual snowfall using observations from 1961 to 2017 in central North America, a region with high contrast in topographic complexities. There is a general, yet distinct difference in the snowfall trends demarcated approximately along the 105° W meridian. To its east, which is dominated by plains, snowfall had increased overall, except in a limited area south of 42° …

Seasonal Patterns Of Surface Inorgamic Carbon System Variables In The Gulf Of Mexico Inferred From A Regional High-Resolution Ocean Biogeochemical Model, Fabian A. Gomez, Rik Wanninkhof, Leticia Barbero, Sang Ki Lee, Frank J. Hernandez

Faculty Publications

Uncertainties in carbon chemistry variability still remain large in the Gulf of Mexico (GoM), as data gaps limit our ability to infer basin-wide patterns. Here we configure and validate a regional high-resolution ocean biogeochemical model for the GoM to describe seasonal patterns in surface pressure of CO₂ (pCO₂), aragonite saturation state (ΩAr), and sea–air CO₂ flux. Model results indicate that seasonal changes in surface pCO₂ are strongly controlled by temperature across most of the GoM basin, except in the vicinity of the Mississippi–Atchafalaya river system delta, where runoff largely controls dissolved inorganic carbon (DIC) …

Effects Of Optical Turbulence And Density Gradients On Particle Image Velocimetry, Silvia Matt, Gero Nootz, Samuel Hellman, Weilin Hou

Faculty Publications

Particle image velocimetry (PIV) is a well-established tool to collect high-resolution velocity and turbulence data in the laboratory, in both air and water. Laboratory experiments are often performed under conditions of constant temperature or salinity or in flows with only small gradients of these properties. At larger temperature or salinity variations, the changes in the index of refraction of water or air due to turbulent microstructure can lead to so-called optical turbulence. We observed a marked influence of optical turbulence on particle imaging in PIV. The effect of index of refraction variations on PIV has been described in air for …

230Th Normalization: New Insights On An Essential Tool For Quantifying Sedimentary Fluxes In The Modern And Quaternary Ocean, Kassandra M. Costa, Christopher T. Hayes, Robert F. Anderson, Frank J. Pavia, Alexandra Bausch, Feifei Deng, Jean Claude Dutay, Walter Geibert, Christoph Heinze, Gideon Henderson, Claude Hillaire-Marcel, Sharon Hoffmann, Samuel L. Jaccard, Allison W. Jacobel, Stephanie S. Kienast, Lauren Kipp, Paul Lerner, Jörg Lippold, David Lund, Franco Marcantonio, David Mcgee, Jerry F. Mcmanus, Figen Mekik, Jennifer L. Middleton, Lise Missiaen, Christelle Not, Sylvain Pichat, Laura F. Robinson, George H. Rowland, Matthieu Roy-Barman, Alessandro Tagliabue, Adi Torfstein, Gisela Winckler, Yuxin Zhou

Faculty Publications

²³⁰Th normalization is a valuable paleoceanographic tool for reconstructing high‐resolution sediment fluxes during the late Pleistocene (last ~500,000 years). As its application has expanded to ever more diverse marine environments, the nuances of ²³⁰Th systematics, with regard to particle type, particle size, lateral advective/diffusive redistribution, and other processes, have emerged. We synthesized over 1000 sedimentary records of ²³⁰Th from across the global ocean at two time slices, the late Holocene (0–5,000 years ago, or 0–5 ka) and the Last Glacial Maximum (18.5–23.5 ka), and investigated the spatial structure of ²³⁰Th‐normalized mass fluxes. On a global scale, …

A Road Map To Indoos-2: Better Observations Of The Rapidly Warming Indian Ocean, L. M. Beal, J. Vialard, M. K. Roxy, J. Li, M. Andres, H. Annamalai, M. Feng, W. Han, R. Hood, T. Lee, M. Lengaigne, R. Lumpkin, Y. Masumoto, M. J. Mcphaden, M. Ravichandran, T. Shinoda, B. M. Sloyan, P. G. Strutton, A. C. Subramanian, T. Tozuka, C. C. Ummenhofer, A. S. Unnikrishnan, J. Wiggert, L. Yu, L. Cheng, D. G. Desbruyères, V. Parvathi

Faculty Publications

The Indian Ocean Observing System (IndOOS), established in 2006, is a multinational network of sustained oceanic measurements that underpin understanding and forecasting of weather and climate for the Indian Ocean region and beyond. Almost one-third of humanity lives around the Indian Ocean, many in countries dependent on fisheries and rain-fed agriculture that are vulnerable to climate variability and extremes. The Indian Ocean alone has absorbed a quarter of the global oceanic heat uptake over the last two decades and the fate of this heat and its impact on future change is unknown. Climate models project accelerating sea level rise, more …

Dynamic Accretion Beneath A Slow-Spreading Ridge Segment: Iodp Hole 1473a And The Atlantis Bank Oceanic Core Complex, Henry J.B. Dick, Christopher J. Macleod, Peter Blum, Natsue Abe, Donna K. Blackman, Julie A. Bowles, M.J. Cheadle, K. Cho, Jakub Ciazela, Jeremy Deans, Virginia P. Edgcomb, C. Ferrando, Lyderic France, B. Ghosh, Benoit Ildefonse, Barbara John, Mark A. Kendrick, J. Koepke, James A.M. Leong, C. Liu, Q. Ma, T. Morishita, A. Morris, J.H. Natland, T. Nozaka, O. Pluemper, A. Sanflippo, J.B. Sylvan, Maurice A. Tivey, R. Tribuzio, G. Viegas

Faculty Publications

809 deep IODP Hole U1473A at Atlantis Bank, SWIR, is 2.2 km from 1,508‐m Hole 735B and 1.4 from 158‐m Hole 1105A. With mapping, it provides the first 3‐D view of the upper levels of a 660‐km² lower crustal batholith. It is laterally and vertically zoned, representing a complex interplay of cyclic intrusion, and ongoing deformation, with kilometer‐scale upward and lateral migration of interstial melt. Transform wall dives over the gabbro‐peridotite contact found only evolved gabbro intruded directly into the mantle near the transform. There was no high‐level melt lens, rather the gabbros crystallized at depth, and then emplaced …

Calibration Of The Lisst-Vsf To Derive The Volume Scattering Functions In Clear Waters, Lianbo Hu, Xiaodong Zhang, Yuanheng Xiong, Ming-Xia He

Faculty Publications

The recently commercialized LISST-VSF instrument measures the volume scattering function (VSF) from 0.1° to 15° with a traditional laser diffraction unit (LISST) and from 15° to 155° with an eyeball component. Between these two optical components, only the LISST unit is calibrated. The eyeball measurements are scaled using the VSFs at 15° that are measured by both components. As this relative calibration relies on a valid measurement at 15° by the LISST, it might fail in clear oceanic waters, where the forward scattering is relative weak either due to a lack of large particles or an overall low concentration of …

A Compilation Of Global Bio-Optical In Situ Data For Ocean-Colour Satellite Applications: Version Two, André Valente, Shubha Sathyendranath, Vanda Brotas, Steve Groom, Michael Grant, Malcolm Taberner, David Antoine, Robert Arnone, William M. Balch, Kathryn Baker, Ray Barlow, Simon Bélanger, Jean-François Berthon, Şükrü Beşiktepe, Yngve Borsheim, Astrid Bracher, Vittorio Brando, Elisabetta Canuti, Francisco Chavez, Andrés Cianca, Hervé Claustre, Lesley Clementson, Richard Crout, Robert Frounin, Carlos García-Soto, Stuart W. Gibb, Richard Gould, Stanford B. Hooker, Mati Kahru, Milton Kampel, Holger Klein, Susanne Kratzer, Raphael Kudela, Jesus Ledesma, Hubert Loisel, Patricia Matrai, David Mckee, Brian G. Mitchell, Tiffany Moisan, Frank Muller-Karger, Leonie O'Dowd, Michael Ondrusek, Trevor Platt, Alex J. Poulton, Michael Repecaud, Thomas Schroeder, Timothy Smyth, Denise Smyth-Wright, Heidi M. Sosik, Michael Twardoski, Vincenzo Vellucci, Kenneth Voss, Jeremy Werdell, Marcel Wernand, Simon Wright, Giuseppe Zibordi

Faculty Publications

A global compilation of in situ data is useful to evaluate the quality of ocean-colour satellite data records. Here we describe the data compiled for the validation of the ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (including, inter alia, MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT and GeP&CO) and span the period from 1997 to 2018. Observations of the following variables were compiled: spectral remote-sensing reflectances, concentrations of chlorophyll a, spectral inherent optical properties, spectral diffuse attenuation coefficients and total suspended matter. The data were from …

A Sustained Ocean Observing System In The Indian Ocean For Climate Related Scientific Knowledge And Societal Needs, J.C. Hermes, Y. Masumoto, L.M. Beal, M.K. Roxy, J. Vialard, M. Andres, H. Annamalai, S. Behera, N. D'Adamo, T. Doi, M. Feng, W. Han, N. Hardman-Mountford, H. Hendon, R. Hood, S. Kido, C. Lee, T. Lee, M. Lengaigne, J. Li, R. Lumpkin, K.N. Navaneeth, B. Milligan, M.J. Mcphaden, M. Ravichandran, T. Shinoda, A. Singh, B. Sloyan, P.G. Strutton, A.C. Subramanian, S. Thurston, T. Tozuka, C.C. Ummenhofer, A.S. Unnikrishnan, R. Venkatesan, D. Wang, J. Wiggert, L. Yu, W. Yu

Faculty Publications

The Indian Ocean is warming faster than any of the global oceans and its climate is uniquely driven by the presence of a landmass at low latitudes, which causes monsoonal winds and reversing currents. The food, water, and energy security in the Indian Ocean rim countries and islands are intrinsically tied to its climate, with marine environmental goods and services, as well as trade within the basin, underpinning their economies. Hence, there are a range of societal needs for Indian Ocean observation arising from the influence of regional phenomena and climate change on, for instance, marine ecosystems, monsoon rains, and …

Modeling Atmosphere-Ocean Radiative Transfer: A Pace Mission Perspective, Jacek Chowdhary, Peng-Wang Zhai, Emmanuel Boss, Heidi Dierssen, Robert Frouin, Amir Ibrahim, Zhongping Lee, Lorraine A. Remer, Michael Twardowski, Feng Xu, Xiaodong Zhang, Matteo Ottaviani, William Reed Espinosa, Didier Ramon

Faculty Publications

The research frontiers of radiative transfer (RT) in coupled atmosphere-ocean systems are explored to enable new science and specifically to support the upcoming Plankton, Aerosol, Cloud ocean Ecosystem (PACE) satellite mission. Given (i) the multitude of atmospheric and oceanic constituents at any given moment that each exhibits a large variety of physical and chemical properties and (ii) the diversity of light-matter interactions (scattering, absorption, and emission), tackling all outstanding RT aspects related to interpreting and/or simulating light reflected by atmosphere-ocean systems becomes impossible. Instead, we focus on both theoretical and experimental studies of RT topics important to the science threshold …

Deep-Ocean Mixing Driving By Small-Scale Internal Tides, Clément Vic, Alberto C. Naveira Garabato, J.A. Mattias Green, Amy F. Waterhouse, Angélique Melet, Casimir De Lavergne, Maarten C. Buijsman, Gordon R. Stephenson

Faculty Publications

Turbulent mixing in the ocean is key to regulate the transport of heat, freshwater and biogeochemical tracers, with strong implications for Earth's climate. In the deep ocean, tides supply much of the mechanical energy required to sustain mixing via the generation of internal waves, known as internal tides, whose fate-the relative importance of their local versus remote breaking into turbulence-remains uncertain. Here, we combine a semi-analytical model of internal tide generation with satellite and in situ measurements to show that from an energetic viewpoint, small-scale internal tides, hitherto overlooked, account for the bulk (>50%) of global internal tide generation, …

Reef Rover: A Low-Cost Small Autonomous Unmanned Surface Vehicle (Usv) For Mapping And Monitoring Coral Reefs, George Raber, Steven R. Schill

Faculty Publications

In the effort to design a more repeatable and consistent platform to collect data for Structure from Motion (SfM) monitoring of coral reefs and other benthic habitats, we explore the use of recent advances in open source Global Positioning System (GPS)-guided drone technology to design and test a low-cost and transportable small unmanned surface vehicle (sUSV). The vehicle operates using Ardupilot open source software and can be used by local scientists and marine managers to map and monitor marine environments in shallow areas (<20>m) with commensurate visibility. The imaging system uses two Sony a6300 mirrorless cameras to collect stereo …

Autonomous Seawater PCo2 And Ph Time Series From 40 Surface Buoys And The Emergence Of Anthropogenic Trends, Adrienne J. Sutton, Richard A. Feely, Stacy Maenner-Jones, Sylvia Musielwicz, John Osborne, Colin Dietrich, Natalie Monacci, Jessica Cross, Randy Bott, Alex Kozyr, Andreas J. Andersson, Nicholas R. Bates, Wei-Jun Cai, Meghan F. Cronin, Eric H. De Carlo, Burke Hales, Stephan D. Howden, Charity M. Lee, Derek P. Manzello, Michael J. Mcphaden, Melissa Meléndez, John B. Mickett, Jan A. Newton, Scott E. Noakes, Jae Hoon Noh, Solveig R. Olafsdottir, Joseph E. Salisbury, Uwe Send, Thomas W. Trull, Douglas C. Vandemark, Robert A. Weller

Faculty Publications

Ship-based time series, some now approaching over 3 decades long, are critical climate records that have dramatically improved our ability to characterize natural and anthropogenic drivers of ocean carbon dioxide (CO₂) uptake and biogeochemical processes. Advancements in autonomous marine carbon sensors and technologies over the last 2 decades have led to the expansion of observations at fixed time series sites, thereby improving the capability of characterizing sub-seasonal variability in the ocean. Here , we present a data product of 40 individual autonomous moored surface ocean pCO₂ (partial pressure of CO₂) time series established between …

Vertical Marine Snow Distribution In The Stratified Hypersaline, And Anoxic Orca Basin (Gulf Of Mexico), Arne Diercks, Kai Ziervogel, Ryan Sibert, Samantha B. Joye, Vernon Asper

Faculty Publications

We present a complete description of the depth distribution of marine snow in Orca Basin (Gulf of Mexico), from sea surface through the pycnocline to within 10 m of the seafloor. Orca Basin is an intriguing location for studying marine snow because of its unique geological and hydrographic setting: the deepest ~200 m of the basin are filled with anoxic hypersaline brine. A typical deep ocean profile of marine snow distribution was observed from the sea surface to the pycnocline, namely a surface maximum in total particle number and midwater minimum. However, instead of a nepheloid (particle-rich) layer positioned near …

A Multiscale Approach To High-Resolution Ocean Profile Observations Within A 4dvar Analysis System, Matthew J. Carrier, John J. Osborne, Hans E. Ngodock, Scott R. Smith, Innocent Souopgui, Joseph M. D'Addezio

Faculty Publications

Most ocean data assimilation systems are tuned to process and assimilate observations to constrain features on the order of the mesoscale and larger. Typically this involves removal of observations or computing averaged observations. This procedure, while necessary, eliminates many observations from the analysis step and can reduce the overall effectiveness of a particular observing platform. Simply including these observations is not an option as doing so can produce an overdetermined, ill-conditioned problem that is more difficult to solve. An approach, presented here, aims to avoid such issues while at the same time increasing the number of observations within the assimilation. …

Enso-Induced Co-Variability Of Salinity, Plantkton Biomass And Coastal Currents In The Northern Gulf Of Mexico, Fabian A. Gomez, Sang-Ki Lee, Frank J. Hernandez Jr., Luciano M. Chiaverano, Frank E. Muller-Karger, Yanyun Liu, John T. Lamkin

Faculty Publications

The northern Gulf of Mexico (GoM) is a region strongly influenced by river discharges of freshwater and nutrients, which promote a highly productive coastal ecosystem that host commercially valuable marine species. A variety of climate and weather processes could potentially influence the river discharges into the northern GoM. However, their impacts on the coastal ecosystem remain poorly described. By using a regional ocean-biogeochemical model, complemented with satellite and in situ observations, here we show that El Niño - Southern Oscillation (ENSO) is a main driver of the interannual variability in salinity and plankton biomass during winter and spring. Composite analysis …

Role Of The Atchafalaya River Basin In Regulating Export Fluxes Of Dissolved Organic Carbon, Nutrients, And Trace Elements To The Louisiana Shelf, Dongjoo Joung, Laodong Guo, Alan M. Shiller

Faculty Publications

The abundance and fluxes of selected dissolved trace elements (TE), nutrients, and dissolved organic carbon (DOC) were quantified in the Atchafalaya River Basin to better understand its influence on the chemical regime of the Louisiana Shelf, a region where bottom water hypoxia occurs annually during late spring to early fall. Water samples were collected from throughout the entire Atchafalaya River Basin including from the Mississippi and Red Rivers as well as basin swamp waters during April and November 2010, and June 2011, which represent “typical” high and low, and “unusual” high river discharges, respectively. Within the total dissolved (< 0.45 µm) pool, most of the TEs were mainly partitioned to the < 0.02 µm dissolved phase with the exception of Cr, Cs, Fe, Pb and Zn which were dominantly in the colloidal (0.02-0.45 µm) phase. In the Atchafalaya River, seasonal concentration variations in nutrients, DOC and most TEs were similar to those in the Mississippi River, reflecting a major contribution of water from the Mississippi River. Contributions of the Red River to the Atchafalaya River’s DOC and nutrients were estimated to be 1-35%, similar to previous estimates for this system. The Red River contribution to the fluxes of Co, Cr, Cs, Fe, Mn, Pb, Rb, and Zn was generally disproportionally high (>20%), …