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Oceanography and Atmospheric Sciences and Meteorology

The University of Southern Mississippi

2020

Articles 1 - 18 of 18

Full-Text Articles in Physical Sciences and Mathematics

Destabilizing Effects On A Classic Tri-Trophic Oyster Reef Cascade, Virginia R. Schweiss, Chet F. Rakocinski Dec 2020

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 …

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Cost-Effective Gnss Hardware For High-Accuracy Surveys And Its Prospects For Post-Processed Kinematic (Ppk) And Precise Point Positioning (Ppp) Strategies, Johnson Olusegun Oguntuase Dec 2020

Cost-Effective Gnss Hardware For High-Accuracy Surveys And Its Prospects For Post-Processed Kinematic (Ppk) And Precise Point Positioning (Ppp) Strategies, Johnson Olusegun Oguntuase

Dissertations

This dissertation determines for the first time the vertical accuracy achievable with low-cost mass-market multi-frequency, multi-GNSS (LM3GNSS) receivers, and antennas in the context of Ellipsoid Reference Survey (ERS), usually employed in bathymetric operations aboard survey platforms. LM3GNSS receivers are relatively new in the market, and their emergence is driven by the automobile industry and several mass-market applications requiring location-based solutions at high accuracies. It is foreseeable that emerging hydrographic survey platforms such as autonomous surface vehicles, small unmanned aircraft, crowd-sourced bathymetric platforms, and offshore GNSS buoy will find LM3GNSS receivers attractive since they are power- and cost-effective (often less than …

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Monitoring 2019 Bonnet Carré Spillway Impacts - Final Report, J. Read Hendon, Jerry D. Wiggert, Jill Hendon Dec 2020

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 …

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Assessing The Recalibration Interval For Nearshore Sediment Assemblages After Hurricane Irma: Implications For Developing Long-Term Records Of Overwash Deposits, Stephen Mitchell Dec 2020

Assessing The Recalibration Interval For Nearshore Sediment Assemblages After Hurricane Irma: Implications For Developing Long-Term Records Of Overwash Deposits, Stephen Mitchell

Master's Theses

Surface distributions are commonly collected to assist with overwash interpretation; however, many of these are first established immediately after a major overwash event as part of a post-event field survey. This study documents the impacts of Hurricane Irma, a Category 5 storm, on nearshore sediments off the coast of Anegada (British Virgin Islands) using distributions of Homotrema rubra, an encrusting foraminifer with a defined provenance in coral reef ecosystems. Over four sampling intervals spanning 2 years, from six months pre-Hurricane Irma to 18 months post-Hurricane Irma, surface sediment was collected from three shore-perpendicular transects on both the northern and …

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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 Oct 2020

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 …

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Utilizing Manganese And Rhenium Sediment Concentrations To Reconstruct Past Interglacial Southern Ocean Circulation Changes, Evan E. Rohde Aug 2020

Utilizing Manganese And Rhenium Sediment Concentrations To Reconstruct Past Interglacial Southern Ocean Circulation Changes, Evan E. Rohde

Honors Theses

The circulation in the Southern Ocean is a component of global nutrient, heat, and carbon cycles. Changes in any of these cycles can dramatically change ocean conditions around the world. Therefore, any changes that occurred to this circulation in the past is of scientific interest. We hypothesize that changes in the glacial cycle of the planet can affect this circulation. Specifically, we hypothesize that the strength of circulation in the Southern Ocean can be reduced by conditions during interglacial, or warm climate, time periods. It is proposed that during the interglacial period of Marine Isotope Stage (MIS) 11 (425 to …

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Freshwater Endmembers Impacting Carbonate Chemistry In The Mississippi Sound, Allison Savoie Aug 2020

Freshwater Endmembers Impacting Carbonate Chemistry In The Mississippi Sound, Allison Savoie

Master's Theses

Coastal ecosystems are highly dynamic areas for carbon cycling and are likely to be negatively impacted by increasing ocean acidification. This research focused on dissolved inorganic carbon (DIC) and total alkalinity (TA) in the Mississippi Sound in order to understand the influence of local rivers that supply alkalinity to the area and buffer against ocean acidification. This area receives large fluxes of freshwater from local rivers, in addition to episodic inputs from the Mississippi River through a human-built diversion, the Bonnet Carré Spillway. Sites in the Mississippi Sound were sampled monthly during August 2018 to November 2019 and at weekly …

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Long Lived Second Mode Internal Solitary Waves In The Andaman Sea, J.M. Magalhaes, J.C.B. Da Silva, Maarten C. Buijsman Jun 2020

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 …

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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 Jun 2020

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 …

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Geochemical Tracers Of Arctic Ocean Processes: A Study Of Gallium, Barium, And Vanadium, Laura M. Whitmore May 2020

Geochemical Tracers Of Arctic Ocean Processes: A Study Of Gallium, Barium, And Vanadium, Laura M. Whitmore

Dissertations

The Arctic Ocean is linked to the global oceans and climate through its connectivity with the North Atlantic Ocean and the regional thermohaline deep water formation sites. It’s also a region undergoing rapid environmental change. To inform the community of potential changes in geochemical and biogeochemical cycles, this dissertation addresses three dissolved geochemical tracers (gallium, barium, and vanadium) as indicators of Arctic Ocean processes. Gallium is tested as a replacement for nutrient-type tracers in an effort to deconvolve Pacific and Atlantic derived waters in the Arctic Ocean basins. These water masses carry different heat and salt content and can influence …

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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 May 2020

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 …

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Changes In Regional Snowfall In Central North America (1961-2017): Mountain Versus Plains, Jiyang Zhang, Haochi Zheng, Xiaodong Zhang, Jeffrey Vanlooy Apr 2020

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° …

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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 Mar 2020

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) …

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Effects Of Optical Turbulence And Density Gradients On Particle Image Velocimetry, Silvia Matt, Gero Nootz, Samuel Hellman, Weilin Hou Feb 2020

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 …

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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 Feb 2020

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, …

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Pelagic Sargassum Prediction And Marine Connectivity In The Tropical Atlantic, Donald R. Johnson, James S. Franks, Hazel A. Oxenford, Shelly-Ann L. Cox Jan 2020

Pelagic Sargassum Prediction And Marine Connectivity In The Tropical Atlantic, Donald R. Johnson, James S. Franks, Hazel A. Oxenford, Shelly-Ann L. Cox

Gulf and Caribbean Research

Since 2011, pelagic Sargassum has experienced extraordinary blooms in the Tropical Atlantic where a system of persistent but seasonally variable currents has retained and consolidated it in large masses. Although beneficial at sea, principally as a unique pelagic habitat, when Sargassum inundates the nearshore environment it can have catastrophic effects on tourism, fisheries, health, and local ecosystems. Providing advanced warning of arrival dates of large masses of Sargassum is critical for enabling preparations and planning for its removal, use, and mitigation. Predictions of arrival time and location involve satellite identification of Sargassum at sea together with ocean current data for …

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Gulf Coast Marine Laboratories Past, Present And Future, Donald F. Boesch Jan 2020

Gulf Coast Marine Laboratories Past, Present And Future, Donald F. Boesch

Gulf and Caribbean Research

I spent my nearly 50—year career in marine science working at marine laboratories, most of that as a chief executive officer. So, it is appropriate that my reflections are about marine laboratories, rather than my own science. After relating my career course, I turn my attention to the history and development of marine laboratories along the U.S. coast of the Gulf of Mexico (GOM). Surprisingly, the region’s first laboratory was actually constructed in 1903 at Cameron, LA, but operated less than a decade before closing. It was not until after World War II that the university—affiliated marine laboratories of today …

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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 Jan 2020

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 …

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