Oceanography and Atmospheric Sciences and Meteorology Commons^™

Classifying Tornadic Storms In The Tennessee Valley, Clara Hochmuth

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Factors Influencing Rainfall Over The Congo, Ajay Raghavendra

Legacy Theses & Dissertations (2009 - 2024)

The hydrological cycle over tropical rainforests includes some of the most intense thunderstorms and rainfall totals. The energy associated with this convective activity plays an important role in the Earth’s weather and climate system. Therefore, the interannual variability, trends, and future climate projections of the hydrological cycle over tropical rainforests are important topics for research. The Congo rainforest situated over equatorial Africa is the second largest rainforest in the world, and recent studies have documented a >30-year large-scale and long-term drying trend over the Congo since the late-1970s. However, unlike the Amazon rainforest in South America, the Congo rainforest is …

The Impact Of Warm Conveyor Belt Forecast Uncertainty On Downstream Predictability, Jeremy Berman

Legacy Theses & Dissertations (2009 - 2024)

Perturbations to the potential vorticity (PV) waveguide can lead to the downstream radiation of Rossby waves, and in turn high-impact weather events. The PV waveguide is often perturbed in association with cyclogenesis, largely due to the latent heat release within the cyclone’s warm conveyor belt (WCB). Previous studies have hypothesized that forecast uncertainty associated with diabatic heating in WCBs can result in large downstream forecast variability; however these studies have not established a direct connection between the two. This hypothesis is evaluated for six cyclogenesis events characterized by highly amplified flow over the North Atlantic using ensemble model simulations.

Ozone And Reactive Oxidized Nitrogen Chemistry In The Northeast U.S, Matthew Ninneman

Legacy Theses & Dissertations (2009 - 2024)

Ongoing reductions in oxides of nitrogen concentrations ([NOx] = nitric oxide ([NO]) + nitrogen dioxide ([NO2])) throughout the continental United States (U.S.) have important implications for tropospheric ozone (O3) and reactive oxidized nitrogen chemistry (NOy ≈ NOx + nitric acid (HNO3) + particle nitrate (pNO3) + peroxy nitrates (PNs) + alkyl nitrates (ANs)). Specifically, decreasing [NOx] concentrations have likely (1) increased the sensitivity of O3 to the [NOx] level, and (2) affected NOy speciation and partitioning. An understanding of the impacts of continued [NOx] reductions is needed to inform current and future air pollution control strategies, especially since the National …

Global Circulation Variability Associated With Mjo Phase Speed, Alexander Marat Tomoff

Legacy Theses & Dissertations (2009 - 2024)

Differences in the Madden–Julian oscillation (MJO) phase speed help explain some of the variability in the global circulation patterns associated with the MJO. Select mechanisms that identify these distinctive circulation signals are applied to help explain MJO variability associated with different phase speeds. Wavelet filter analysis is first used to compute regression models of the MJO at different phase speeds, isolating the associated patterns in outgoing longwave radiation (OLR), geopotential height, and upper-level wind. Covariance matrices provide a deeper understanding of how the tropical and extratropical patterns compare between two phase speeds at any point in time. Both Fourier and …

An Analysis Of Temperature Trends In The Northeast United States : 1950-2019, Christopher Selca

Legacy Theses & Dissertations (2009 - 2024)

The warming signal associated with anthropogenic climate change shows a significant positive trend globally over the last century. Trends in the magnitude and frequency of annual mean and extreme events do not display a globally uniform signal, as some regions have shown negative trends. This study examines the trends in daily mean and extreme temperatures in the Northeast region of the United States. Station data was selected from the GHCN-D Version 3 data set, using a blend of stations from the weather forecast offices and the cooperative observing network. Station criteria included using a threshold of less than 5% of …

Examining The Impact Of Synoptic-Scale Waves On Stratospheric Polar Vortex Variability From An Ensemble Forecast Perspective, Michael E. Main

Legacy Theses & Dissertations (2009 - 2024)

Major Sudden Stratospheric Warming (SSW) events are characterized by rapid warming of the polar regions at 10 hPa and are accompanied by a reversal of the 10-hPa zonal-mean zonal wind at 60˚N from westerly to easterly. Following an SSW event, stratospheric thermal and momentum anomalies can progress downward and linger near the tropopause for up to 60 days. These anomalies have major impacts on tropospheric sensible weather including increased likelihood of cold air outbreaks and heavy precipitation events. SSW events are largely forced by upward propagation of planetary-scale Rossby waves from the troposphere to the stratosphere. Synoptic-scale waves can contribute …

Dynamical Downscaling Of Near-Term Climate Variability And Change For The Main Hawaiian Islands Using Wrf, Katrina Marie Fandrich

Legacy Theses & Dissertations (2009 - 2024)

As climate models continue to improve, the demand from resource managers and decision-makers for more accurate climate projections is increasing. However, natural climate variability poses a limit to the confidence in regional climate change projections, particularly for the mid-21st century. The unique geographic location of the Hawaiian Islands and its regional climate provide a challenging opportunity for climate modelers. The goal of this project is to examine both the Pacific Decadal Oscillation (PDO) and anthropogenic climate change for their impacts on near-term rainfall and temperature projections for the Hawaiian Islands. Of primary interest are the questions 1) is there a …

Improving Our Understanding Of The Relationship Between Ocean Heat Uptake And Climate Sensitivity, Michael Cameron Rencurrel

Legacy Theses & Dissertations (2009 - 2024)

One of the ultimate goals of the field of climate science is to determine exactly how sensitive the Earth is to anthropogenic forcing, with far reaching implications both from a scientific and policy standpoint. However, despite decades of observational and model analysis, large uncertainties in Earth's climate sensitivity persist. Recent advances have shown that climate feedbacks, the primary mechanism driving the sensitivity spread, are dependent on the spatial patterns of the surface response, intrinsically linked to how the ocean is working to uptake and transport energy across the globe. Given the importance of reducing the range of climate sensitivity from …

Easterly Waves Over The Eastern Pacific, Victor Manuel Torres Puente

Legacy Theses & Dissertations (2009 - 2024)

The research in this thesis explores different processes associated with the life cycle of Easterly Waves over the tropical Eastern Pacific. These include genesis, structural evolution, intensification and a dissipating stage.

Evaluating Large-Scale And Storm-Scale Characteristics Of Rapidly Intensifying And Slowly Intensifying Tropical Cyclones Using An Analog Approach, Jannetta C. Richardson

Legacy Theses & Dissertations (2009 - 2024)

Tropical cyclone (TC) intensity change is modulated by a combination of large-scale and storm-scale processes. On the large-scale, several factors exhibit strong controls on TC rapid intensification (RI): the initial TC intensity, the environmental vertical wind shear (VWS), and the background thermodynamic environment, which determines the TC’s maximum potential intensity (MPI). Previous statistical studies comparing RI and non-RI TCs have shown that TCs undergoing RI tend to be embedded in environments of lower VWS, and have initial intensities that are farther from their MPIs. Although numerous statistical studies have compared the large-scale and storm-scale conditions of RI and non-RI TCs, …

The Significance Of The Nontraditional Coriolis Terms In Tropical Large-Scale Dynamics, Heng Wang

Legacy Theses & Dissertations (2009 - 2024)

The nontraditional Coriolis terms (NCTs) turn eastward motion upward and upward motion westward, and vice versa. NCTs are omitted in most of the current global atmospheric models. However, NCTs are significant in tropical large-scale dynamics in at least three aspects. 1) Using an idealized model that can switch NCTs on or off, omitting NCTs biases large-scale flow response to prescribed diabatic forcing mimicking the intertropical convergence zone (ITCZ). The omission yields a westerly wind bias in the heating region ~ 10% of the westerly jet stream. This bias is due to lack of westward NCT when heating-induced upward motion is …

Estimating Abiotic Thresholds For Sagebrush Condition Class In The Western United States, Stephen Boyte, Bruce K. Wylie, Yingxin Gu, Donald J. Major

United States Geological Survey: Staff Publications

Sagebrush ecosystems of the western United States can transition from extended periods of relatively stable conditions to rapid ecological change if acute disturbances occur. Areas dominated by native sagebrush can transition from species-rich native systems to altered states where non-native annual grasses dominate, if resistance to annual grasses is low. The non-native annual grasses provide relatively little value to wildlife, livestock, and humans and function as fuel that increases fire frequency. The more land area covered by annual grasses, the higher the potential for fire, thus reducing the potential for native vegetation to reestablish, even when applying restoration treatments. Mapping …

Applied Injected Air Into Subsurface Drip Irrigation: Plant Uptake Of Pharmaceuticals And Soil Microbial Communities, Matteo D'Alessio, Lisa M. Durso, Clinton Williams, Christopher A. Olson, Chittaranjan Ray, Ellen Paparozzi

Nebraska Water Center: Faculty Publications

The growing global food security crisis is complicated by the need for increased crop production with less arable land and limited water resources. Reuse of treated wastewater for agricultural irrigation is becoming more common, often paired with other conservation measures such as subsurface drip irrigation (SDI). Passively injecting air into SDI systems increases crop yields and overcomes root zone wetting issues. However, when used with treated irrigation water, contaminants in the water might be taken up by the crops. This paper investigates the impact of air-injected water containing caffeine, carbamazepine, and gemfibrozil on plant uptake and soil microbial communities in …

Droughtscape, Winter 2019, Cory Matteson

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

4th quarter climate summary

2019 year in review summary

4th quarter drought impact summary

2019 drought impact summary

New form helps ‘see more’ drought

Landscape photographers invited to submit photos

Helping Central and South America planning

Database includes more drought planning

An International Laboratory Comparison Of Dissolved Organic Matter Composition By High Resolution Mass Spectrometry: Are We Getting The Same Answer?, Jeffrey A. Hawkes, Juliana D'Andrilli, Jeffrey N. Agar, Mark P. Barrow, Stephanie M. Berg, Núria Catalán, Hongmei Chen, Rosalie K. Chu, Richard B. Cole, Thorsten Dittmar, Rémy Gavard, Gerd Gleixner, Patrick G. Hatcher, Chen He, Nancy J. Hess, Ryan H.S. Hutchins, Amna Ijaz, Hugh E. Jones, William Kew, Maryam Khaksari, Diana Catalina Palacio Lozano, Jitao Lv, Lynn R. Mazzoleni, Beatriz E. Noriega-Ortega, Helena Osterholz, Nikola Radoman, Christina K. Remucal, Nicholas D. Schmitt, Simeon K. Schum, Quan Shi, Carsten Simon, Gabriel Singer, Rachel L. Sleighter, Aron Stubbins, Mary J. Thomas, Nikola Tolic, Shuzhen Zhang, Phoebe Zito, David C. Podgorski

Chemistry & Biochemistry Faculty Publications

High-resolution mass spectrometry (HRMS) has become a vital tool for dissolved organic matter (DOM) characterization. The upward trend in HRMS analysis of DOM presents challenges in data comparison and interpretation among laboratories operating instruments with differing performance and user operating conditions. It is therefore essential that the community establishes metric ranges and compositional trends for data comparison with reference samples so that data can be robustly compared among research groups. To this end, four identically prepared DOM samples were each measured by 16 laboratories, using 17 commercially purchased instruments, using positive-ion and negative-ion mode electrospray ionization (ESI) HRMS analyses. The …

Nrlmsis 2.0: A Whole-Atmosphere Empirical Model Of Temperature And Neutral Species Densities, J. T. Emmert, D. P. Drob, J. M. Picone, D. E. Siskind, M. Jones Jr., M. G. Mlynczak, Peter F. Bernath, X. Chu, E. Doornbos, B. Funke, L. P. Goncharenko, M. E. Hervig, M. J. Schwartz, P. E. Sheese, F. Vargas, B. P. Williams, T. Yuan

Chemistry & Biochemistry Faculty Publications

NRLMSIS® 2.0 is an empirical atmospheric model that extends from the ground to the exobase and describes the average observed behavior of temperature, eight species densities, and mass density via a parametric analytic formulation. The model inputs are location, day of year, time of day, solar activity, and geomagnetic activity. NRLMSIS 2.0 is a major, reformulated upgrade of the previous version, NRLMSISE-00. The model now couples thermospheric species densities to the entire column, via an effective mass profile that transitions each species from the fully mixed region below ~70 km altitude to the diffusively separated region above ~200 km. Other …

"We Would Ride Safely In The Harbor Of The Future": Historical Parallels Between The Existential Threats Of Yellow Fever And Sea Level Rise In New Orleans And Norfolk, Morris W. Foster, Emily E. Steinhilber

Division of Research and Economic Development Faculty & Staff Publications

The 19th century experiences of Yellow Fever epidemics in New Orleans and Norfolk present historical parallels for how those cities, and others, are experiencing existential threats from climate change and sea level rise in the 21st century. In particular, the 19th century ?Sanitary Reform? movement can be interpreted as a model for challenges facing 21st century ?Climate Resilience? initiatives, including denialism and political obfuscation of scientific debates as well as tensions between short-term profit and the cost of long-term infrastructure investments and between individualism and communitarianism. The history of Sanitary Reform suggests that, at least in the U.S., Climate Resilience …

Science, Diplomacy, And The Red Sea's Unique Coral Reef: It's Time For Action, Karine Kleinhaus, Ali Al-Sawalmih, Daniel J. Barshis, Amatzia Genin, Lola N. Grace, Ove Hoegh-Guldberg, Yossi Loya, Anders Meiborn, Eslam O. Osman, Jean-Daniel Ruch, Yonathan Shaked, Christian R. Voolstra, Assaf Zvuloni, Maoz Fine

Biological Sciences Faculty Publications

Rapid ocean warming due to climate change poses a serious risk to the survival of coral reefs. It is estimated that 70–90 percent of all reefs will be severely degraded by mid-century even if the 1.5°C goal of the Paris Climate Agreement is achieved. However, one coral reef ecosystem seems to be more resilient to rising sea temperatures than most others. The Red Sea’s reef ecosystem is one of the longest continuous living reefs in the world, and its northernmost portion extends into the Gulf of Aqaba. The scleractinian corals in the Gulf have an unusually high tolerance for the …

Assessing If Motivation Impacts General Aviation Pilots’ Persistence In Varying Weather Conditions, Sabrina Woods

Doctoral Dissertations and Master's Theses

Continued flight under visual flight rules into instrument meteorological conditions is the predominant cause for fatal accidents by percentage, for general aviation aircraft operations. It is possible that a pilot’s motivation or reason for flying will override other safer, more logical courses of action when a hazard presents itself. The decision appears to stem from a willingness to persist in a course of action despite factors that indicate an alternate and safer course is warranted. This research addresses what is currently presumed about the decision to continue flying under visual flight rules into instrument conditions and marries those ideas with …