Oceanography and Atmospheric Sciences and Meteorology Commons^™

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. …

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 …

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).

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 …

Hysplit In Simulating The Atmospheric Dispersion Of Hazardous Aerosols: A Case Study In St. Louis, Missouri, Ahmet Tolga Odabasi

Masters Theses

"Atmospheric dispersion and transmission play an important role in the behavior and effects of air pollution. Human health can be adversely affected by air pollution in a variety of ways, both immediately and over time. The Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) modeling program, a computer model and software package, tracks the transport trajectories and distributions of air pollution and various pollutants, including radioactive pollutants, in the atmosphere. It also facilitates research on pollution sources. This study simulated the transport of hazardous aerosols in St. Louis region for the years 2020, 2021, and 2022 using the HYSPLIT modeling …

Quantifying The Influence Of The Madden-Julian Oscillation On Rainfall Extremes During The Northeast Monsoon Season Of The Philippines, Lyndon Mark P. Olaguera, John A. Manalo, Alwin Bathan, Jun Matsumoto

Physics Faculty Publications

This study investigates the impact of the Madden–Julian Oscillation (MJO) on the extreme rainfall events across 11 eastern coastal stations during the northeast monsoon season (November to March) over the Philippines from 1979 to 2019. The contribution of synoptic systems to these extreme rainfall events such as tropical cyclones (TCs), low-pressure systems (LPS), cold surges (CS), and other disturbances as they coincide with a strong and active MJO were quantified. The results show that the probability of extreme rainfall occurrence increases first to as much as 20% in the southernmost stations in Phase 4. Then, it increases to more than …

The Effects Of Temperature, Flooding, And Goose Feces Addition On Greenhouse Gas Emissions And Ammonification In Four High-Latitude Soils From Western Alaska, Jenna M. Ross

Electronic Theses and Dissertations

The large carbon (C) stock of wetlands is vulnerable to climate change, especially in high latitudes that are warming at a disproportional rate. Likewise, low-elevation Arctic coastal areas will flood more frequently under climate change and sea-level rise, which may alter goose herbivory and fecal deposition patterns if geese move inland. While temperature, flooding, and feces impact soil C emissions, their interactive effects have been rarely studied. Here, I explore the impact of these interactions on CO2 and CH4 emissions and nitrogen (N) mineralization (ammonification) in soils collected from four plant communities in the Yukon-Kuskokwim (Y-K) Delta, a high latitude …

Effects Of El Nino And Sunspot Cycles On Global And Reginal Climate, August Nathan Tolzman

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Sunspots and El Nino affect the interannual variability of temperature on earth. Separately there is a positive relationship between higher sunspots and warmer temperatures or more intense El Nino and warmer temperatures globally and in Missoula. This is with the bias of climate change removed. Putting these two processes together it is expected that when intense El Ninos and high sunspots happen in the same year there will be warmer temperatures. This was not the case, there was no data to support that putting these to processes together makes them more or less intense.

Investigating Microphysical Variability And Entrainment In Clouds Using Airborne Digital Holography, Machine Learning, And Large Eddy Simulations, Nithin Allwayin

Dissertations, Master's Theses and Master's Reports

Advancing our understanding of cloud microphysics—the processes governing cloud particles' formation, growth, and interactions—is essential for accurate weather and climate modeling. In this work, we investigate how droplet size distributions vary in a cloud and explore how microphysical properties such as droplet size and number concentration respond to entrainment and mixing.

In the first part of the work, a novel algorithm is developed combining hypothesis testing with density-based clustering to identify characteristic cloud droplet size distribution types in marine stratocumulus clouds. Applied to data from the airborne Holographic Detector for Clouds (HOLODEC), the algorithm successfully identifies a relatively small set …

Trends In Atmospheric Composition Between 2004-2023 Using Version 5 Ace-Fts Data, Matthew Schmidt, Peter Bernath, Chris Boone, Michael Lecours, Johnathan Steffen

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment (ACE) is a satellite mission that has been in orbit since 2003. The primary instrument on ACE is a Fourier transform spectrometer (FTS) that records infrared atmospheric transmittance spectra in the limb geometry using the Sun as a light source. Version 5 of ACE-FTS data processing contains improved volume mixing ratio (VMR) profiles for 46 molecules and 24 isotopologues, including HFC-32 (CH₂F₂) and HOCl as new routine data products. VMR trends for each of the 46 molecules are reported for regions of atmospheric interest. Specifically, the longevity of the ACE mission has …

Application Of Density Altitude Climatology To General Aviation Impacts, Thomas A. Guinn, Daniel J. Halperin, Sarah Strazzo

Journal of Aviation/Aerospace Education & Research

Density altitude (DA) plays a key role in flight safety because it helps pilots anticipate poor aircraft performance when temperatures are warmer than standard. In this study, a 30-year climatology of DA for the conterminous United States was created using the fifth-generation European Centre for Medium-Range Weather Forecasts atmospheric reanalysis of the global climate (ERA5) dataset was applied to four separate DA-based, aircraft-performance, rules-of-thumb for general aviation (GA) flight. The goal was to demonstrate a technique to create educational visualization tools showing the variation of operational flight impacts with both month and location. Four such parameters were chosen to show …

Life Cycle Greenhouse Gas Emissions In Maize No-Till Agroecosystems In Southern Brazil Based On A Long-Term Experiment, Guilherme Rosa Da Silva, Adam J. Liska, Cimelio Bayer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Brazilian agriculture is constantly questioned concerning its environmental impacts, particularly greenhouse gas (GHG) emissions. This research study used data from a 34-year field experiment to estimate the life cycle GHG emissions intensity of maize production for grain in farming systems under no-tillage (NT) and conventional tillage (CT) combined with Gramineae (oat) and legume (vetch) cover crops in southern Brazil. We applied the Feedstock Carbon Intensity Calculator for modeling the “field-to-farm gate” emissions with measured annual soil N₂O and CH₄ emissions data. For net CO₂ emissions, increases in soil organic C (SOC) were applied as a proxy, …

On The Understanding Of The Coastal-Urban Nexus Of Weather, Air Quality And Energy, Harold Gamarro

Dissertations and Theses

Urban environments exhibit complex interactions between atmospheric processes, building energy consumption, and air quality, particularly during periods of seasonal extremes such as summer ozone peaks and winter heating. Accurate representation of these interactions in urban modeling is crucial for understanding and addressing air pollution and energy management challenges in cities. This research presents a comprehensive study that advances urban atmosphere simulations by integrating building energy dynamics, air quality, and robust multi-source observational evaluation. Leveraging the Weather Research and Forecasting (WRF) model, coupled with a multilayer building environment parameterization (BEP) and a building energy model (BEM), with an improved boundary layer …

Predictability Of Downslope Windstorms And Mechanisms Controlling Their Onset, Matthew James Brewer

Electronic Theses & Dissertations (2024 - present)

Downslope windstorms in the western United States often contribute to the ignition and ex- acerbation of existing wildfires due to their hot, dry, and gusty nature. Accurate forecasts of these windstorms are imperative for mitigating wildfire risk. However, forecasting downslope windstorms remains challenging due to their sensitivity to environmental conditions.

The Sundowner Windstorms of the Santa Barbara, California region have been asso- ciated with many large wildfires in the area. This study analyzes special observations from the Sundowner Wind Experiment field campaign to better understand the diurnal cycle of these windstorms. Analysis of the strongest windstorm during the campaign indicates …

Sources And Significance Of Symmetric Instability In The Outflow Layer Of Tropical Cyclones, Minghao Zhou

Electronic Theses & Dissertations (2024 - present)

The tropical cyclone (TC) outflow layer is an integral part of the TC transverse circulation: warm and moist air converges in the boundary layer of the TC; rising motion and condensational heating occur in the TC eyewall and rainbands; the TC warm core and divergent anticyclone establish in the mid-upper troposphere, with the mass imported into the TC center exported away through outflow near the tropopause.

A series of state-of-the-art numerical simulations were utilized to investigate different scenarios of TC outflow evolution, from an idealized axisymmetric setup to a semi-idealized asymmetric setup, to a real-case setup of TC–trough interaction. Large …

Investigating The Uncertainties Of Forecasting Ne Cold Season Precipitation In Numerical Weather Prediction Models, Yanna Chen

Electronic Theses & Dissertations (2024 - present)

A major winter storm on March 2, 2018, posed significant challenges in predicting precipitation type (P-type) in the northeast U.S., particularly the Hudson Valley. While National Weather Service (NWS) forecasts predicted a mix of rain and snow, observations showed predominantly snow, with errors in snow depth forecasts of 8-12 inches near Albany.

This study used the Weather Research and Forecasting (WRF) model to investigate how model physics (microphysics, cumulus, boundary layer, and radiation schemes) and domain configuration influenced snow depth predictions. Results revealed significant sensitivities to cumulus and radiation schemes, as well as the vertical resolution in the middle troposphere. …

The Future Of Convective Mode In The United States, Jeremy Malcolm Corner

Graduate Research Theses & Dissertations

This work examines potential changes in convective mode associated with hazardous convective weather (HCW) using a suite of high-resolution regional climate simulations and artificial intelligence/machine learning (AI/ML). An AI/ML model called a convolutional neural network (CNN) is first generated and validated using an existing dataset of composite reflectivity images centered on tornado reports from 1996 – 2017 called SVRIMG (SeVeRe IMaGes). Each image in SVRIMG is annotated with four possible convective modes: 1) cellular; 2) mixed mode; 3) linear; and 4) other. The best-performing model, which achieves an accuracy exceeding 90% on testing images, is then used to diagnose storm …

A Climatology And Characteristics Of Midwest Heavy Snowfall, Benjamin William Warren

Graduate Research Theses & Dissertations

Understanding the characteristics of snowfall across the Midwest U.S. is critical for regional ecosystems, water cycles, and socioeconomic activities. The Midwest, however, has not been the primary focus of snow-related research in recent years. Therefore, this research uses observational and reanalysis data in the Midwest from 1991 through 2020 and radar data from 2009 through 2020 to create a comprehensive snowfall climatology, investigate regional trends in heavy snowfall, and determine the frequency of banded versus non-banded snowfall. As expected, heavy snowfall (i.e., daily snowfall accumulation >4") is most frequent in northern Midwest (e.g., Iowa, Minnesota, and Wisconsin), with the frequency …

The Impact Of Thunderstorms On Take-Off Data In South Africa, Quinton Jacobs Mr.

International Journal of Aviation, Aeronautics, and Aerospace

Aviation and meteorology are entwined disciplines, as aviation occurs in the atmosphere. Prevailing weather conditions at take-off are of utmost importance to aviation. This determines the payload of the aircraft and runway in use. Forecast verification is essential to aviation as it determines the quality of the forecasting products. The tolerances for take-off data are stringent and slightly relaxed tolerances are used in South Africa by mutual agreement.

There are six aerodromes in South Africa where Take-off Data are produced, in varying climatic conditions as South Africa is in both the tropics and midlatitudes. Thunderstorms are a common occurrence over …

A Comparison Of Arctic And Atlantic Basin Cyclone Predictability From A Climatology And Case Study Perspective, Peyton Capute

Electronic Theses & Dissertations (2024 - present)

Arctic cyclones (ACs) can transport warm, moist air into the Arctic region, which combined with strong winds may lead to rapid declines in sea ice during the summer. As a consequence, accurate sea ice predictions during the summer may rely on being able to predict cyclone-related wind speed and direction, which critically depends on the cyclone track and intensity. Despite this, there are relatively few studies that have documented the predictability of ACs during the summer, beyond a few case studies. In addition, there has been no extensive comparison of whether these cyclones are more or less predictable relative to …

Using Airborne Measurements To Evaluate Forecasts Of Freezing Drizzle Aloft Results From The Wintre-Mix Field Campaign, Megan Schiede

Electronic Theses & Dissertations (2024 - present)

Icing associated with the accretion of supercooled large droplets (SLD) serves as a significant hazard to aviation activities. Forecasting SLD events is complex due in part to the limitations of numerical weather prediction models. The Winter Precipitation Type Research Multiscale Experiment (WINTRE-MIX) aimed to comprehend such limitations within numerical forecasts of precipitation type (p-type) through the use of extensive observations during events with multiple p-types. To investigate precipitation processes aloft in winter storms with near-freezing surface conditions, research flights were orchestrated with the National Research Council of Canada Convair-580 aircraft. This study examines a WINTRE-MIX intensive observing period that took …

Understanding Local And Large-Scale Drivers Of Rainfall Variability And Change Over The Hawaiian Islands Region, Katrina Fandrich

Electronic Theses & Dissertations (2024 - present)

Hawaiian rainfall variability is strongly influenced by anthropogenic climate change and natural variability (e.g., Pacific Decadal Oscillation (PDO), Pacific North American (PNA) pattern, El Niño–Southern Oscillation (ENSO)). For local decision-makers and resource managers, understanding the drivers of rainfall variability and change in Hawai‘i is crucial for climate adaptation and mitigation planning. Previous studies have applied statistical and dynamical downscaling to produce high-resolution rainfall projections for the Hawaiian Islands region. However, to date, downscaling has only been used to investigate the influence of anthropogenic forcing on late-century rainfall projections for the Hawaiian Islands. For regions like Hawai’i, that are highly vulnerable …

The Importance Of Ice Microphysics In Storm Electrification, Yichen Cai

Electronic Theses & Dissertations (2024 - present)

Evanescent but powerful, lightning is the vast scale release of storm energy from accumulation of minuscule cloud particle interactions. Although lightning occurrence seems random, thunderstorms “electrify” themselves in methodical ways and show structured patterns. This study explores the role of ice microphysics in thunderstorm charging and discharge through numerical simulation.

A squall line has been simulated ideally and realistically with generally consistent conclusions. Drastically different amount of lightning was produced when using three different microphysical models: Depending on the choice of charging scheme, the National Severe Storm Laboratory (NSSL) two-moment model appropriately captures or overestimate the amount observed by the …

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. …

Data In 'Development At The University Of North Dakota Of A Digital Thermosonde Instrument For The Study Of Atmospheric Optical Turbulence (C_N^2)', Blake T. Sorenson, David J. Delene

Datasets

A thermosonde, an instrument that measures very high resolution temperature difference between two fine-wire platinum thermocouples, was attached to a weather balloon and lifted through the atmosphere, collecting observations of optical turbulence, in the spring of 2018 and 2019. The thermosonde collected raw temperature difference measurements, while an onboard Graw DFM-09 radiosonde observed standard meteorological parameters (temperature, air pressure, wind speed, wind direction, relative humidity, and altitude). The Graw meteorological observations are housed in the .txt files, while the raw radiosonde data (containing the raw, encoded thermosonde measurements) are housed in the .gsf files. The decoded voltage and temperature difference …

Deep Learning Approaches For Chaotic Dynamics And High-Resolution Weather Simulations In The Us Midwest, Vlada Volyanskaya, Kabir Batra, Shubham Shrivastava

Discovery Undergraduate Interdisciplinary Research Internship

Weather prediction is indispensable across various sectors, from agriculture to disaster forecasting, deeply influencing daily life and work. Recent advancement of AI foundation models for weather and climate predictions makes it possible to perform a large number of predictions in reasonable time to support timesensitive policy- and decision-making. However, the uncertainty quantification, validation, and attribution of these models have not been well explored, and the lack of knowledge can eventually hinder the improvement of their prediction accuracy and precision. Our project is embarking on a two-fold approach leveraging deep learning techniques (LSTM and Transformer) architectures. Firstly, we model the Lorenz …

An Investigation Into Past And Future Freezing Level Height And Equilibrium Line Altitude In The Tropical Andes Using Cmip6, Shelby Turner

Legacy Theses & Dissertations (2009 - 2024)

The freezing level height (FLH) in the tropical Andes has increased over the past several decades, as is evident with the receding of alpine glaciers in this region. The accuracy of Global Climate Models (GCMs)—specifically previous generations of the Coupled Model Intercomparison Project (CMIP)—in this region remains an issue, as the complex terrain and climate characteristics are difficult to simulate realistically. The changes seen in these tropical alpine glaciers in the past few decades are a clear indicator of the effects climate change is having in this tropical mountain region, making it important to better understand current and projected future …

Characterizing And Understanding Orographic Precipitation Over The Mountains Of Extratropical South America, Yazmina Rojas Beltran

Legacy Theses & Dissertations (2009 - 2024)

Extratropical South-America (30-40°S) varies significantly in topography, including a coastal mountain range with elevation from 700-1300 m, a central valley, and the Andes, with elevation from 1000-2500 m on the western side of the continent. The topography of the area can disrupt frontal systems approaching from the Pacific Ocean, leading to enhanced orographic precipitation over the windward slope of the Andes and a sharp rain shadow, with less precipitation in the leeside. These phenomena are also observed over the coastal mountains of south-central Chile. The main goals of this study are to characterize and understand orographic precipitation and rain shadow …

Initiation Criteria For The Onset Of Geomagnetic Substorms Based On Auroral Observations And Electrojet Current Signatures, Mayowa Michael Kayode-Adeoye

Graduate Theses and Dissertations (2019 - present)

In recent years, several substorm onset criteria have been developed, either from auroral observations (many authors) or from auroral electrojet properties such as those described by (Forsyth et al., 2015; Maimaiti et al., 2019; Newell & Gjerloev, 2011; Partamies et al., 2011) The different criteria are being investigated using a low order physics model of the magnetosphere called WINDMI (Spencer et al., 2009) and inferences are being made in line with the WINDMI model. The model variables will be compared with the criteria for substorm onset proposed by examining the SML index.

The WINDMI model uses solar wind and IMF …