Digital Commons Network^™

Characterizing Differential Reflectivity Calibration Dependence On Environmental Temperature Using The X-Band Teaching And Research Radar (Xtrra): Looking For A Relationship Between Temperature And Differential Reflectivity Bias, Emma Miller

The Journal of Purdue Undergraduate Research

Calibration scans are important for the maintenance of data and the quality of the information that radars output. In this study we looked for a temperature dependency in a full year’s worth of differential reflectivity (ZDR) calibration scan data collected by the X-band Teaching and Research Radar (XTRRA) located near the Purdue University campus. In a vertically pointing calibration scan, the radar scans the drops from below while rotating. From this angle, the overall shape will be circular, which corresponds to a ZDR value of approximately 0 dB. To process the data for the year 2021, a Python script was …

A Computational Profile Of Invasive Lionfish In Belize: A New Insight On A Destructive Species, Joshua E. Balan

The Journal of Purdue Undergraduate Research

Since their discovery in the region in 2009, invasive Indonesian-native lionfish have been taking over the Belize Barrier Reef. As a result, populations of local species have dwindled as they are either eaten or outcompeted by the invaders. This has led to devastating losses ecologically and economically; massive industries in the local nations, such as fisheries and tourism, have suffered greatly. Attempting to combat this, local organizations, from nonprofits to ecotourism companies, have been manually spear-hunting them on scuba dives to cull the population. One such company, Reef Conservation Institute (ReefCI), operating out of Tom Owens Caye outside of Placencia, …

Clouds In The Ancient Lunar Atmosphere: Water Ice Nucleation On Aerosol Simulants, Mariana C. Aguilar

The Journal of Purdue Undergraduate Research

Today’s moon is vastly different from what it was 3 billion years ago. At that time, it was home to a collisional atmosphere formed through massive amounts of volcanism, releasing enough subsurface gas to sustain surface pressures of up to 1 kPa. Observations of our solar system have taught us that all dense atmospheres are host to clouds and aerosols, and we expect the Moon’s to be no different. Knowing when, where, and under what conditions cloud particles form is important for understanding the evolution of the lunar atmosphere, how it reacted to temperature gradients, and how it cycled volatiles. …

2024 January 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Ecological Assessment Of Drainage Water Input On The Water Quality Of A Coastal Estuary, Mediterranean Coast Of Egypt, Fatma A. Zaghloul, Hoda A. E. Hemaida, Hayat M. Faragallah, Ahmed A. Radwan

Blue Economy

El Mex Bay, located west of Alexandria City, is identified as a hot spot of pollution along the Mediterranean coast of Egypt. It is a large, shallow, and turbid water body of socioeconomic importance. However, El Mex Bay receives a large amount of untreated industrial wastewater, as well as agricultural runoff from different land-based sources.

A comprehensive environmental study was carried out seasonally during 2020-2021. To evaluate the effect of this discharged wastewater on the water quality of El Mex Bay.

The physicochemical parameters were measured at both the surface and near-bottom water at nine stations.

Principal component analysis indicated …

Spatial Analyses On Pre-Earthquake Ionospheric Anomalies And Magnetic Storms Observed By China Seismo-Electromagnetic Satellite In August 2018, Jann-Yeng Tiger Liu, Xuhui Shen, Fu-Yuan Chang, Yuh-Ing Chen, Yang-Yi Sun, Chieh‑Hung Chen, Sergey Pulinets, Katsumi Hattori, Dimitar Ouzounov, Valerio Tramutoli, Michel Parrot, Wei-Sheng Chen, Cheng-Yan Liu, Fei Zhang, Dapeng Liu, Xue-Min Zhang, Rui Yan, Qiao Wang

Mathematics, Physics, and Computer Science Faculty Articles and Research

The China Seismo-Electromagnetic Satellite (CSES), with a sun-synchronous orbit at 507 km altitude, was launched on 2 February 2018 to investigate pre-earthquake ionospheric anomalies (PEIAs) and ionospheric space weather. The CSES probes manifest longitudinal features of four-peak plasma density and three plasma depletions in the equatorial/low-latitudes as well as mid-latitude troughs. CSES plasma and the total electron content (TEC) of the global ionosphere map (GIM) are used to study PEIAs associated with a destructive M7.0 earthquake and its followed M6.5 and M6.3/M6.9 earthquakes in Lombok, Indonesia, on 5, 17, and 19 August 2018, respectively, as well as to examine ionospheric …

Weakened Pelagic-Benthic Coupling On An Arctic Outflow Shelf (Northeast Greenland) Suggested By Benthic Ecosystem Changes, Yasemin V. Bodur, Paul E. Renaud, Lidia Lins, Luana Da Costa Monteiro, William G. Ambrose, Janine Felden, Thomas Krumpen, Frank Wenzhöfer, Maria Włodarska-Kowalczuk, Ulrike Braeckman

Marine Science

Arctic marine ecosystems are becoming more boreal due to climate change. Predictions of ecosystem change focus mainly on Arctic inflow or interior shelves, with few comprehensive studies on Arctic outflow regions. During September–October 2017, soft-bottom communities were sampled and benthic ecosystem processes were quantified at 12 stations on the Northeast Greenland shelf (outflow shelf) and compared to the last regional ecosystem study, conducted in 1992 and 1993. The benthic habitat was characterized in terms of sediment granulometry, pigment concentrations, and porewater chemistry (dissolved inorganic carbon, nutrients). Total abundance and biomass of macrobenthos and meiobenthos, bacterial abundance, porewater dissolved inorganic carbon …

2024 January 18 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Evaluation Of Seven Satellite-Based And Two Reanalysis Global Terrestrial Evapotranspiration Products, Zijing Xie, Yunjun Yao, Qingxin Tang, Meng Liu, Joshua B. Fisher, Jiquan Chen, Xiaotong Zhang, Kun Jia, Yufu Li, Ke Shang, Bo Jiang, Junming Yang, Ruiyang Yu, Xueyi Zhang, Xiaozheng Guo, Lu Liu, Jing Ning, Jiahui Fan, Lilin Zhang

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Although comprehensive evaluation of different types of global terrestrial evapotranspiration (ET) products has been conducted, the satellite remote sensing techniques have prompted the development of several available global ET products, warranting a reassessment as products continue to evolve. Recently, we produced the long-term Global LAnd Surface Satellite (GLASS) ET product, but there is a lack of comparison and evaluation with other ET products and EC observations on a global scale. In this study, we evaluated the accuracy and uncertainty of seven satellite-based (GLASS-AVHRR, GLASS-MODIS, BESS, FLUXCOM, GLEAM, MOD16, and PML_V2) and two reanalysis (ERA5 and MERRA2) global terrestrial ET products …

Estimation Of Sugarcane Yield Using Multi-Temporal Sentinel 2 Satellite Imagery And Random Forest Regression, Alireza Taravat, Gebeyehu Abebe, Berhan Gessesse, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

Advancements in remote sensing techniques have greatly enhanced crop monitoring and yield estimation, with spectral vegetation indices (VIs) serving as a key component. Our study investigates the use of Sentinel-2 data, notable for its red-edge bands, in estimating sugarcane yield in Ethiopia's Awash Basin. Utilizing 22 VIs from S2 imagery, our approach combines Random Forest (RF) regression with the Recursive Feature Elimination (RFE) algorithm to improve the accuracy of sugarcane yield predictions. The results demonstrate the superior performance of the RF-RFE method over traditional RF with full datasets and Stepwise Multiple Regression (SMR). Particularly, VIs focusing on the red-edge spectral …

Detection And Classification Of Sporadic E Using Convolutional Neural Networks, J. A. Ellis, Daniel J. Emmons, M. B. Cohen

Faculty Publications

In this work, convolutional neural networks (CNN) are developed to detect and characterize sporadic E (E_s), demonstrating an improvement over current methods. This includes a binary classification model to determine if Es is present, followed by a regression model to estimate the Es ordinary mode critical frequency (foEs), a proxy for the intensity, along with the height at which the Es layer occurs (hEs). Signal-to-noise ratio (SNR) and excess phase profiles from six Global Navigation Satellite System (GNSS) radio occultation (RO) missions during the years 2008–2022 are used as the inputs of the model. Intensity (foEs) and the …

Editorial: Observations And Simulations Of Layering Phenomena In The Middle/Upper Atmosphere And Ionosphere, Bingkun Yu, Xuguang Cai, Daniel J. Emmons Ii, Chong Wang, Jainfei Wu

Faculty Publications

The middle/upper atmosphere and ionosphere are the transition between neutral and ionized components of the Earth’s atmosphere, including stratosphere, mesosphere, thermosphere, ionospheric E region and ionospheric F region (Laštovička et al., 2006; Xu, et al., 2007; Smith, 2012). The atmospheric thermal structure and composition are significantly affected by dynamical processes through coupling. The layering phenomena such as mesospheric metal layers, sporadic E layers, and noctilucent clouds are important tracers to study mechanisms of the vertical coupling from the lower to the upper atmosphere (Dou et al., 2010; Plane, 2012; Xue et al., 2013).

2024 January 11 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

2024 January 4 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Fluid Flow, Mineralization And Deformation In An Oceanic Detachment Fault: Microtextural, Geochemical And Isotopic Evidence From Pyrite At 13°30′N On The Mid-Atlantic Ridge, Andrew J. Martin, John W. Jamieson, Sven Petersen, Mostafa Fayek, Javier Escartin

Geoscience Faculty Research

Hydrothermal fluids in ultramafic-hosted hydrothermal systems associated with oceanic detachment faults can be more oxidizing compared to mafic-hosted vent sites. These fluids form a mineral assemblage of pyrite, magnetite and hematite. At 13°30′N on the Mid-Atlantic Ridge, chlorite-quartz breccias recovered from an exposed fault scarp contain pyrite, with abundant magnetite and hematite, indicating that the redox of the fluids was variable. In primary micron-scale zonations in pyrite, Ni, Co, and Se have a decoupled relationship, recording fluctuations in the chemical composition and temperature of hydrothermal fluid as the grains grew. Secondary zonations that erase and overprint primary zonations are limited …

Fish Assemblage Structure In Great Lakes Coastal Wetlands Over Ten Years, Matthew S. Silverhart

Masters Theses

Coastal wetlands in the Laurentian Great Lakes are important habitats for many fish species. The geographic scale of the watershed and the diversity of land uses in the region result in substantial environmental variation among coastal wetlands. During 2011-2020, annual surveys were conducted as part of the Great Lakes Coastal Wetland Monitoring Program (GLCWMP) to better understand the status and trends of coastal wetlands. Fish sampling consisted of fyke netting in monodominant vegetation zones. During this time, 1225 unique monodominant plant zones in coastal wetlands were sampled, resulting in 584,125 fishes captured that consisted of 113 different species. Yellow Perch …

Using Repeat Photography To Document The Effects Of Climate Change On Glaciers In Iceland Change On Glaciers In Iceland, Madeleine Gassin

Environmental Studies Honors Papers

Climate change is a worldwide, multifaceted phenomenon that impacts our world today and will continue to impact our world in the future with even greater severity. Although climate change can sometimes be considered an abstract topic due to its being somewhat intangible, one direct way of observing the effects of climate change is by studying glaciers. This study combines a literature review with repeat photography in order to demonstrate the tangible effects of climate change on glaciers in Iceland and explore the secondary impacts on sea level elevation (SEL), water availability and distribution, hydropower, natural hazards, and tourism in Iceland. …

Atmospheric And Earth Science 498 Professsional Development, Tess Olten, Robert Griffin

Open Educational Resources (OER)

Whether you're already in the workforce, or you're still in school and haven't yet applied for your first position -- the job application process can be both exciting and demoralizing. Sometimes, finding a new job feels like a full-time job itself -- especially when the competition is steep and the field of candidates is crowded.

How can you help yourself stand out from other applicants and land the job of your dreams? In this course, you'll work through each step of the application process, as well as consider graduate school as an alternative or additional choice. First, you'll explore tips …

Sarah Pohjola, Senior Art Exhibition Portfolio, Earth's Destruction, Sarah Pohjola

Senior Art Portfolios

This work was created for the Senior Art Exhibition Portfolio 2024. This work includes graphic design and illustration focused on environmental conservation.

Coordinated Cosmic-Ray Observing System (Ccros) Concept Paper, Trenton E. Franz

School of Natural Resources: Faculty Publications

The Coordinated Cosmic-Ray Observation System Conference (CCROS) was held October 14-16, 2024, at the University of Nebraska-Lincoln (USA), and seven strategic priorities and needs were identified.

Water-Level And Recoverable Water In Storage Changes, High Plains Aquifer, Predevelopment To 2019 And 2017 To 2019, Virginia L. Mcguire, Kellan R. Strauch

United States Geological Survey: Water Reports and Publications

The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial groundwater irrigation (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2019 and from 2017 to 2019.

Water-level changes from predevelopment to 2019, by well, ranged from a rise of 86 feet to a decline of 265 feet; the range for …

Effectiveness Of Municipal Collaboration For Watershed Management In The Southern Colorado River Basin, Sasha Geschwind

CGU Theses & Dissertations

There are mixed arguments about the best scale of government for providing various public goods and services. Specifically, the management of a watershed, which can be categorized as a common pool resource, is generally implemented at the local government scale via National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer Systems (MS4) permits as issued by the United States Environmental Protection Agency (US EPA). A large body of literature argues for rethinking this scale because this does not match natural watershed boundaries.In this paper, I explore the question: Does collaboration, and type of collaboration, among jurisdictions within a watershed …

Critical Convergence: Mapping The Boundaries Of How Faculty Interrogate Whiteness In The Geoscience Educational Landscape, James E. Hobbs

Educational Leadership & Policy Studies Dissertations - Archive

This study examined the role of faculty members in interrogating whiteness within geoscience education. The dominant reliance on whiteness as the primary way of knowing in geoscience education has long perpetuated a singular perspective that serves as a mechanism for reinforcing existing power structures rooted in white supremacy. Drawing on tenets from Critical whiteness Studies, Curriculum Theory, and Transformative Learning Theory, this research investigated U.S. higher education faculty members' strategies and challenges in disrupting whiteness within the geoscience curriculum.

Through critical qualitative narrative inquiry, data were collected through semi-structured interviews with geoscience faculty members across multiple institutions across the United …

Multimodel Approach To A Support Stock Assessment Of Standardized Catch And Effort Data: A Case Study Of Blue Shark (Prionace Glauca) In The Indian Ocean By The Taiwanese Large-Scale Longline Fishery, Chun-Yi Hung, Hoang Huy Huynh, Xing-Han Wu, Wen-Pei Tsai

Journal of Marine Science and Technology–Taiwan

In the context of stock assessment and fishery conservation, determining catch per unit effort (CPUE) accurately and reliably is essential. This study estimated trends in the relative abundance of blue sharks (Prionace glauca) in the Indian Ocean from 2005 to 2022. Blue sharks constitute a resilient bycatch species in pelagic tuna and swordfish longline fisheries. We employed a multimodel approach that included delta-lognormal, zero-inflated negative binomial, and vector autoregressive spatiotemporal (VAST) models to standardize catch rates recorded by observers in the Taiwanese large-scale longline fishery. Our analysis concentrated on the CPUE of blue sharks, including standardizing the number of fish …

Differential Impacts Of Weather Anomalies On Household Energy Expenditure Shares: A Comparison Of Clustered Panel Analysis Methods, Jordan Champion

Theses and Dissertations--Agricultural Economics

Recent emphasis on environmental justice has highlighted deficiencies in our energy system that produce disparities in accessibility and affordability for the most vulnerable. Meanwhile, the realities of a gradually warming climate and the onset of a global energy crisis (IEA 2022) have coincidently contributed to spikes in both energy prices and demand. These implications threaten to further exacerbate existing disparities for income-constrained and vulnerable populations, enhancing their risk of falling into prolonged insecurity. To ensure our transition to a just, sustainable future, we must first ensure equitable access to affordable and reliable energy for everyone. Combining household-level panel and state-level …

Toward The Unified Theory Of Said-Linked Subauroral Arcs, Evgeny V. Mishin, Anatoly V. Streltsov

Publications

We present a unified approach to subauroral arcs within intense subauroral ion drifts (SAID), which explains the observed transition of a precursor Stable Auroral Red (SAR) arc into Strong Thermal Emission Velocity Enhancement (STEVE). This approach is based on the short-circuiting concept of fasttime SAID as an integral part of a magnetospheric voltage generator between the innermost boundaries of the freshly injected plasma sheet electrons and ring current ions. Here, enhanced plasma turbulence rapidly heats the bulk plasma and accelerates suprathermal non-Maxwellian “tails.” Heat and suprathermal electron transport rapidly elevate the ionospheric electron temperature—the source of a bright SAR arc. …

Fretting Corrosion Wear Of Titanium-Based Alloy (Ti-6al-4v) In 0.9 Wt.% Nacl Solution, Chen-En Lu, Wen-Ken Li, Hung-Hua Sheu, Jeou-Long Lee, Hung-Bin Lee

Journal of Marine Science and Technology–Taiwan

In this study, a high precision fretting tribo-corrosion tester used to analyze the wear and corrosion behavior of Ti alloys in a fretting motion condition. The tester, operated in a ball-on-plate mode, was employed in the fretting corrosion study of metallic bio-materials (Ti and Ti-6Al-4V) under different loads (0 and 10 N), electrolytes (0.9 wt% NaCl and SBF) and fixed displacement frequency (1 Hz). Using profilometer, optical microscope in the experimental analysis and three-body mechanism in the theoretical analysis, the fretting corrosion performances of these bio-medical metals, such as velocity accommodation characteristics, friction, wear, and scratch profile were examined in …

A New-Type Deep Learning Model Based On Shapley Regulation For Containerized Freight Index Prediction, Yen-Chang Shih, Ming-Shue Lin, Taih-Cherng Lirn, Jih-Gau Juang

Journal of Marine Science and Technology–Taiwan

In this study, we have crafted an innovative methodology that represents a groundbreaking synthesis of deep learning techniques with cooperative game theory. In this study, we use the accuracy of data prediction by different LSTM models as a measurement index and assign different LSTM models corresponding weights through the Shapley value calculation method to construct a more accurate predictive analysis model. We use this improved Shapley regulation model to calibrate a long short-term memory (LSTM) neural network by using historical freight data to predict the China Container Freight Index (CCFI), the leading export container freight index commonly used in China. …

Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure, Chien-Cheng Chen, Yuan-Liang Jeng, Shun-Chang Yen

Journal of Marine Science and Technology–Taiwan

The exhaust back pressure of diesel engines becomes increasing higher nowadays. As an example, the De-NOx system and DE-SOx system necessitated by the increasingly stringent emission standards, would result in increased exhaust back pressure for those diesel engines adopting such systems. Some ships adopt underwater exhaust system to save space on the working deck and to reduce noise and air pollution, while the hydrostatic pressure under water level has made the exhaust back pressure of diesel engines getting much higher. Under high exhaust back pressure, to keep discharging exhaust unhindered and operating smoothly for diesel engine, it often results in …

Elimination Of Noise In A Ship Cabin Using Multi-Layered Acoustic Boards: An Apso And Sa Approach, Min-Chie Chiu, Ho-Chih Cheng

Journal of Marine Science and Technology–Taiwan

A high level of noise, combined with pure tones, is often encountered in ship's cabins, leading to severe psychological and physiological issues for the crew. To address this problem, an indoor noise abatement solution becomes necessary that utilizes efficient acoustic boards integrated with resonators, positioned along the inner walls of the cabin. However, the thickness of the acoustic boards must be strictly limited due to maintenance and operational considerations. This limitation results in insufficient sound absorption capabilities and a restricted range of tuned frequencies, as the resonating frequency of a standard Helmholtz resonator is closely tied to its cavity. A …