Oceanography and Atmospheric Sciences and Meteorology Commons^™

Water Quality Monitoring At Impaired Sites On The Cache River, Ar, Usa, Molly Elaine Kennon-Lacy

Student Theses and Dissertations

Cache River Watershed, AR has several impairments, including: dissolved lead (Pb) and copper (Cu), and total dissolved solids (TDS). Eight sites were monitored monthly measuring: pH, conductivity, DO, total suspended solids (TSS), TDS, turbidity, hardness, dissolved and total nutrients and metals (Pb and Cu), to add to ADEQ’s database. Flow was measured to determine if there was a relationship between measured parameters and periods of low or high flow. Filtration size (0.45 vs 0.20 µm) was compared to conclude if using different size filters on water samples affected concentrations of metals in water. Bioassays were performed using aquatic organisms on …

Future Changes In Propagating And Non-Propagating Diurnal Rainfall Over East Asia, Wan-Ru Huang, Shih-Yu (Simon) Wang

Plants, Soils, and Climate Faculty Publications

The characteristics of diurnal rainfall in the East Asian continent consist of a propagating regime over the Yangtze River and a non-propagating regime in southeast China. Simulations of these two diurnal rainfall regimes by 18 CMIP5 models were evaluated from the historical experiment of 1981–2005. The evaluation led to the identification of one model, the CMCC-CM that replicated the key characteristics of diurnal rainfall regimes including the propagation of moisture convergence. Using the CMCC-CM to assess the future (2076–2100) change of diurnal evolution and propagation projected by the RCP4.5 experiment, it was found that propagating diurnal rainfall will enhance and …

Dynamics Of Orographic Gravity Waves Observed In The Mesosphere Over Auckland Islands During The Deep Propagating Gravity Wave Experiment (Deepwave), Stephen D. Eckermann, Dave Broutman, Jun Ma, James D. Doyle, Pierre-Dominique Pautet, Michael J. Taylor, Katrina Bossert, Bifford P. Williams, David C. Fritts, Ronald B. Smith

Publications

On 14 July 2014 during the Deep Propagating Gravity Wave Experiment (DEEPWAVE), aircraft remote sensing instruments detected large-amplitude gravity wave oscillations within mesospheric airglow and sodium layers at altitudes z ~ 78–83 km downstream of the Auckland Islands, located ~1000 km south of Christchurch, New Zealand. A high-altitude reanalysis and a three-dimensional Fourier gravity wave model are used to investigate the dynamics of this event. At 0700 UTC when the first observations were made, surface flow across the islands’ terrain generated linear three-dimensional wave fields that propagated rapidly to z ~ 78 km, where intense breaking occurred in a narrow …

An Exploration Of Wind Stress Calculation Techniques In Hurricane Storm Surge Modeling, Kyra M. Bryant, Muhammad Akbar

Mechanical and Manufacturing Engineering Faculty Research

As hurricanes continue to threaten coastal communities, accurate storm surge forecasting remains a global priority. Achieving a reliable storm surge prediction necessitates accurate hurricane intensity and wind field information. The wind field must be converted to wind stress, which represents the air-sea momentum flux component required in storm surge and other oceanic models. This conversion requires a multiplicative drag coefficient for the air density and wind speed to represent the air-sea momentum exchange at a given location. Air density is a known parameter and wind speed is a forecasted variable, whereas the drag coefficient is calculated using an empirical correlation. …

Breakdown Of Itcz-Like Pv Patterns, Ajay Raghavendra, Thomas A. Guinn

Beyond: Undergraduate Research Journal

The Inter-Tropical Convergence Zone (ITCZ) is a zonal belt of intense convection, responsible for the genesis of over 80% of all tropical cyclones. This region of intense diabatic heating and shear results in a maximum of Ertel's potential vorticity (PV) meeting Rayleigh's necessary condition for barotropic instability. A fundamental issue is understanding the necessary precursor events leading to the breakdown of the ITCZ and subsequent formation of tropical cyclones. Our research examines the non-linear PV dynamics of the breakdown of both finite-length and infinite-length vorticity strips of varying widths and shapes, simulating the ITCZ found near the tropical eastern Pacific …

Hydroclimatic Contrasts Over Asian Monsoon Areas And Linkages To Tropical Pacific Ssts, Hai Xu, Jianghu Lan, Enguo Sheng, Bin Liu, Keke Yu, Yuanda Ye, Zhengguo Shi, Peng Cheng, Xulong Wang, Xinying Zhou, Kevin M. Yeager

Earth and Environmental Sciences Faculty Publications

Knowledge of spatial and temporal hydroclimatic differences is critical in understanding climatic mechanisms. Here we show striking hydroclimatic contrasts between northern and southern parts of the eastern margin of the Tibetan Plateau (ETP), and those between East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) areas during the past ~2,000 years. During the Medieval Period, and the last 100 to 200 years, the southern ETP (S-ETP) area was generally dry (on average), while the northern ETP (N-ETP) area was wet. During the Little Ice Age (LIA), hydroclimate over S-ETP areas was wet, while that over N-ETP area was dry …

Drought In A Human-Modified World: Reframing Drought Definitions, Understanding, And Analysis Approaches, Anne F. Van Loon, Kerstin Stahl, Giuliano Di Baldassarre, Julian Clark4, Sally Rangecroft, Niko Wanders, Tom Gleeson, Albert I. J. M. Van Dijk, Lena M. Tallaksen, Jamie Hannaford, Remko Uijlenhoet, Adriaan J. Teuling, David M. Hannah, Justin Sheffield, Mark D. Svoboda, Boud Verbeiren, Thorsten Wagener, Henny A. J. Van Lanen

National Drought Mitigation Center: Faculty Publications

In the current human-modified world, or Anthropocene, the state of water stores and fluxes has become dependent on human as well as natural processes.Water deficits (or droughts) are the result of a complex interaction between meteorological anomalies, land surface processes, and human inflows, outflows, and storage changes. Our current inability to adequately analyse and manage drought in many places points to gaps in our understanding and to inadequate data and tools. The Anthropocene requires a new framework for drought definitions and research. Drought definitions need to be revisited to explicitly include human processes driving and modifying soil moisture drought and …

Estimation Of Temporal Variations In Path-Averaged Atmospheric Refractive Index Gradient From Time-Lapse Imagery, Santasri Basu, Jack E. Mccrae, Steven T. Fiorino, Jared Przelomski

Faculty Publications

The sea level vertical refractive index gradient in the U.S. Standard Atmosphere model is −2.7×10⁻⁸  m⁻¹ at 500 nm. At any particular location, the actual refractive index gradient varies due to turbulence and local weather conditions. An imaging experiment was conducted to measure the temporal variability of this gradient. A tripod mounted digital camera captured images of a distant building every minute. Atmospheric turbulence caused the images to wander quickly, randomly, and statistically isotropically and changes in the average refractive index gradient along the path caused the images to move vertically and more slowly. The temporal variations of …

Quantifying The Toxicity Of 1-Methylnaphthalene To The Shallow-Water Coral, Porites Divaricata, For Use In The Target Lipid Model, Nicholas Turner

HCNSO Student Theses and Dissertations

The proximity of coral reefs to coastal urban areas and shipping lanes predisposes corals to petroleum pollution from multiple sources. Previous research has evaluated petroleum toxicity to coral using a variety of methodologies, including monitoring effects of acute and chronic spills, in situ exposures, and ex situ exposures with both adult and larval stage corals. Variability in toxicant, bioassay conditions, species and other methodological disparities among studies prevents comprehensive conclusions regarding the toxicity of hydrocarbons to corals. This research evaluated the 48-hour toxicity of 1-methylnaphthalene to Porites divaricata using a continuous-flow passive dosing system. The range-finding exposure evaluated the dosing …

Tibetan Plateau Geladaindong Black Carbon Ice Core Record (1843–1982): Recent Increases Due To Higher Emissions And Lower Snow Accumulation, Matthew Jenkins, Susan Kaspari, Kang Shi-Chang, Bjorn Grigholm, Paul A. Mayewski

Student Published Works

Black carbon (BC) deposited on snow and glacier surfaces can reduce albedo and lead to accelerated melt. An ice core recovered from Guoqu glacier on Mt. Geladaindong and analyzed using a Single Particle Soot Photometer (SP2) provides the first long-term (1843–1982) record of BC from the central Tibetan Plateau. Post 1940 the record is characterized by an increased occurrence of years with above average BC, and the highest BC values of the record. The BC increase in recent decades is likely caused by a combination of increased emissions from regional BC sources, and a reduction in snow accumulation. Guoqu glacier …

Icelandic Fisheries: Scenario Planning For Climate Change, Tara Sorrels

Mahurin Honors College Capstone Experience/Thesis Projects

This study aimed to develop an understanding of how a scenario planning process could be used to assist businesses to adapt to climate change. The focus of this study was on the Icelandic fishing industry since Iceland is experiencing firsthand climate change impacts. Mitigation strategies are the main focus in climate change research, but this study focused on a possible adaptation method that requires changing management practices in order to reduce the impact of climate change on the economy. Tours of Icelandic fisheries and interviews with individuals within the Icelandic fishing industry were conducted to assess the current adaptive capacity …

How Did The Deepwater Horizon Oil Spill Impact Deep-Sea Ecosystems?, Charles R. Fisher, Paul A. Montagna, Tracey Sutton

Marine & Environmental Sciences Faculty Articles

Approximately 90% of the volume of the Gulf of Mexico is contained in water deeper than 200 m, a region where the Deepwater Horizon (DWH) blowout had more impact on ecosystems than any previous oil spill. The remoteness and relative inaccessibility of the deep sea makes documenting even acute impacts to the animals that live in this realm difficult. This article reviews Natural Resource Damage Assessment studies and follow-up work funded as part of the Gulf of Mexico Research Initiative that targeted deepwater pelagic and benthic fauna. Oil was incorporated into the pelagic food web, and a reduction in planktonic …

Umphlett Qci Sept 2016, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Streamflow Conditions

Challenging Season for Bird Breeding

Mixed Impacts to Agriculture this Summer

Unprecedented Fish Kill on Yellowstone River

3-Month Precipitation and Temperature Outlooks

Soil Moisture Conditions

Using Rare Earth Elements To Constrain Particulate Organic Carbon Flux In The East China Sea, Chin-Chang Hung, Ya-Feng Chen, Shih-Chieh Hsu, Kui Wang, Jianfang Chen, David J. Burdige

OES Faculty Publications

Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Recent research has shown that POC fluxes in the ECS may be overestimated due to active sediment resuspension. To better characterize the effect of sediment resuspension on particle fluxes in the ECS, rare earth elements (REEs) and organic carbon (OC) were used in separate two-member mixing models to evaluate trap-collected POC fluxes. The ratio of resuspended particles from sediments to total trap-collected particles in the ECS ranged from 82-94% using the OC mixing …

Tidal-Fluvial And Estuarine Processes In The Lower Columbia River: Ii. Water Level Models, Floodplain Wetland Inundation, And System Zones, David A. Jay, Amy B. Borde, Heida Diefenderfer

Civil and Environmental Engineering Faculty Publications and Presentations

Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetland …

On Safety Assessment Of Novel Approach To Robust Uav Flight Control In Gusty Environments, Vladimir Golubev, Petr Kazarin, William Mackunis, Sherry Borener, Derek Hufty

Publications

In a follow-up to our previous study, the current work examines the gust-induced “cone of uncertainty” in a small unmanned aerial vehicle’s (UAV) flight trajectory addressed in the context of safety assessments of UAV operations. Such analysis is a critical facet of the integration of unmanned aerial systems (UAS) into the National Airspace System (NAS), particularly in terminal airspace. The paper describes a predictive, robust feedback-loop flight control model that is applicable to various classes of UAVs and unsteady flight-path scenarios. The control design presented in this paper extends previous research results by demonstrating asymptotic (zero steady-state error) altitude regulation …

Systematic Bias In Baroclinic Energy Estimates In Shelf Seas, Gordon R. Stephenson, J. A. Mattias Green, Mark E. Inall

Faculty Publications

A simple model of an internal wave advected by an oscillating barotropic flow suggests flaws in standard approaches to estimating properties of the internal tide. When the M₂ barotropic tidal current amplitude is of similar size to the phase speed of the M₂ baroclinic tide, spectral and harmonic analysis techniques lead to erroneous estimates of the amplitude, phase, and energy in the M₂ internal tide. In general, harmonic fits and bandpass or low-pass filters that attempt to isolate the lowest M₂ harmonic significantly underestimate the strength of M₂ baroclinic energy fluxes in shelf seas. Baroclinic …

An Analysis Of The Moisture And Moist Static Energy Budgets In Amip Simulations, Kristine Adelaide Boykin

Theses and Dissertations

An analysis of the second phase of the Atmospheric Model Intercomparison Project (AMIP) simulations has been conducted to understand the physical processes that control precipitation in the tropics. This is achieved primarily through the analysis of the moisture and moist static energy budgets. Overall, there is broad agreement between the simulated and observed precipitation, although specific tropical regions such as the Maritime Continent poses challenges to these simulations. The models in general capture the latitudinal distribution of precipitation and key precipitating regions including the Inter-Tropical Convergence Zone (ITCZ) and the Asian Monsoon. The simulations portrayed the global patterns of evaporation …

Presence Of The Cyanotoxin Microcystin In Arctic Lakes Of Southwestern Greenland, Jessica Trout-Haney, Zachary Wood, Kathryn Cottingham

Dartmouth Scholarship

Cyanobacteria and their toxins have received significant attention in eutrophic temperate and tropical systems where conspicuous blooms of certain planktonic taxa release toxins into fresh water, threatening its potability and safe use for recreation. Although toxigenic cyanobacteria are not confined to high nutrient environments, bloom-forming species, or planktonic taxa, these other situations are studied les often studied. For example, toxin production in picoplankton and benthic cyanobacteria—the predominant photoautotrophs found in polar lakes—is poorly understood. We quantified the occurrence of microcystin (MC, a hepatotoxic cyanotoxin) across 18 Arctic lakes in southwestern Greenland. All of the focal lakes contained detectable levels of …

Watershed Response To Climate Change And Fire-Burns In The Upper Umatilla River Basin Using The Precipitation Runoff Modeling System, Kimberly Crystal Yazzie

Dissertations and Theses

This study provides an analysis of watershed response to climate change and forest fire impacts, to better understand the hydrologic budget and inform water management decisions for present and future needs. The study site is 2,365 km², located in the upper Umatilla River Basin (URB) in northeastern Oregon. The Precipitation Runoff Modeling System, a distributed-parameter, physical-process watershed model, was used in this study. Model calibration yielded a Nash Sutcliffe Model Efficiency of 0.73 for both calibration (1995-2010) and validation (2010-2014) of daily streamflow. Ten Global Climate Models using Coupled Model Intercomparison Project Phase 5 experiments with Representative Concentration …