Atmospheric Sciences Commons^™

Convective Modes Associated With Precipitation Exceeding Postfire Debris Flow Thresholds In The Southwestern United States, Anya M. Aponte Torres

Graduate Research Theses & Dissertations

Postfire debris flows can occur when surface-water runoff dislodges and carries a slurry of loose sediment and vegetation downslope, usually in steep, recently burned terrain. Short-duration, high-intensity rainfall embedded within short or long-duration rainstorms (e.g., thunderstorms and atmospheric rivers) is most commonly associated with this mode of debris-flow initiation. The typical horizontal grid spacings of global numerical weather prediction and general circulation models are too coarse to resolve these convective precipitation features, which poses an obstacle to short-term forecasting and investigating future trends in the frequency, magnitude, and characteristics of debris-flow generating rainfall. For this study, 15-minute precipitation and simulated …

A Dynamically Adapting Forecast Cone Based On Ensemble Spread, Michael N. Barletta

Electronic Theses & Dissertations (2024 - present)

Dynamically based ensemble prediction systems have gained considerable attention because they can provide a greater range of possible forecast outcomes and quantify the uncertainty in forecasts. In turn, forecasters can convey clearer messages to the public on the range of forecast scenarios and display inherent uncertainty in weather forecasts, which can be difficult to do with deterministic forecasts. Although global ensemble prediction systems have demonstrated skill in their probabilistic track predictions, the information contained within them is not always fully utilized beyond the mean forecast and standard deviation (i.e., spread). One way that these ensembles could be better employed is …

Analysis Of Extreme Rainfall And Streamflow Events In The Catskill/Delaware Catchment Using The New York State Mesonet, Ada Ellingworth

Electronic Theses & Dissertations (2024 - present)

Extreme rainfall and streamflow often lead to increased turbidity in reservoirs in the Catskill/Delaware catchment, which is part of the New York City water supply system. To better understand extreme events that lead to increased turbidity, this study takes a dual approach: first, we identify hydrologic conditions during extremes to understand when and why extremes occur. Next, we evaluate an identified extreme case to evaluate mesoscale model skill in this region. Measurements from the New York State Mesonet and United States Geological Survey are used to identify hydrologic conditions from 2017-2024 associated with three extreme event types: rainfall, streamflow, and …

The Large-Scale Flow Dynamics And Controls On Recurving Eastern North Pacific Tropical Cyclones, Alexander Kyle Mitchell

Electronic Theses & Dissertations (2024 - present)

While eastern North Pacific (EPAC) tropical cyclones (TCs) most often move westward over open water, a subset deviates from this typical path, recurving toward higher latitudes or making landfall along the North American coastline. Because such events are relatively rare, they have received less attention, despite their significant contributions to rainfall and wildfire activity across the southwestern United States. This dissertation identifies and characterizes the spatial variability of EPAC TC tracks, analyzes the synoptic environments associated with TC recurvature near the North American coast, presents a detailed case study of two recurving EPAC TCs from late September to early October …

Deep Convection, Lightning, And Inertio-Gravity Waves: An Analysis Of Precipitation And Wave Dynamics In The Congo Basin, Stephen L. Solimine

Electronic Theses & Dissertations (2024 - present)

The lack of an extensive in situ observation network throughout equatorial Africa makes it difficult to monitor the Congo climate system. Model and reanalysis products have been used to fill informational gaps but often produce disparate results. To improve model representation of deep convection over the Congo, it’s important to first understand the influence of various thermodynamic and dynamic forces that may be underrepresented. Although satellite based remote sensing retrievals and reanalysis have their own set of limitations, they can offer a great deal of insight into the climate of regions otherwise lacking in observational networks.

The first section of …

Cloud Condensation Nuclei Activity Of Fresh And Aged Phenolic Acid Aerosol Particles, Emily A. Nortmann

Honors Undergraduate Theses

In recent years, the incidence of wildfires has considerably increased, with fire seasons starting earlier and ending later than usual due to changes in snowpack, precipitation, and temperature, which are attributed in part to climate change. Wildfires are responsible for the emission of a variety of gases and organic aerosol particles in the atmosphere with profound impacts on air quality, visibility, and human health. The aerosol particles produced by wildfires can contribute to climate change by scattering or absorbing solar radiation, affecting the radiative balance of the planet through cooling or warming effects, or by acting as cloud condensation nuclei …

Understanding The Dynamical Mechanisms Governing Northern Hemisphere Wintertime Persistent Flow Regimes And Their Associated Extreme Weather Events, Tyler Christopher Leicht

Electronic Theses & Dissertations (2024 - present)

Weather regimes are characterized as patterns of low-frequency variability in the middle to upper troposphere of the extratropics. Weather regimes can also be linked to variations in surface weather, making the study of weather regimes a bridge between traditional synoptic-dynamic meteorology and subseasonal-to-seasonal variability. This dissertation identifies and categorizes persistent flow regimes (PFRs), analyzes the dynamics underpinning PFR formation, identifies the linkages to atmospheric teleconnections, and examines the occurrence of surface weather extremes before and during PFRs.

PFRs are identified from 1979–2022 and grouped into five clusters using k-means clustering, which then allows for time-lag composite analysis to determine the …

Validating Atmospheric Freezing Level Heights Using Purdue University Weather Balloon Data, Danielle Harr

The Journal of Purdue Undergraduate Research

No abstract provided.

A Meteorological Investigation Of A Tornado- Producing, “Hybrid” Supercell-Multicell Storm Near Delphi, Indiana, On May 8, 2023, Evelyn Rose K. Girardi

The Journal of Purdue Undergraduate Research

No abstract provided.

Discrimination The Roles Of Anthropogenic Greenhouse Gases And Aerosols On Tropical Cyclone Frequency From Downscaling Cmip6 Models, George Gyabaah

Theses and Dissertations

Tropical cyclones (TCs) are devastating disasters, yet predicting their future activity remains highly uncertain. To better understand the impacts of different anthropogenic forcings, specifically greenhouse gases (GHG) and aerosols on the TCs, I downscaled the single forcing experiments of 11 CMIP6 models in the Columbia HAZard Model (CHAZ). This analysis focused on changes in the distribution of the North Atlantic (ATL) and Western North Pacific (WNP) basins and explored the shift in environmental variables that drive them. We then used the formulation of the genesis component of CHAZ as a constraint to quantify the relative contribution of each predictor relative …

Advancing S2s Precipitation Outlooks Through The Weather Regime-Gaussian Mixture Model Framework, Wei Zhang

Funded Research Records

No abstract provided.

Modeling Hourly Storm Surges Using Deep Learning Techniques, Md Abu Zafor

Master's Theses

Storm surges cause coastal flooding, one of the most devastating coastal hazards. Accurate modeling of storm surges is essential for predicting and mitigating these impacts. Traditional approaches model surges at individual tide gauges and often focus on daily time scales, leading to data redundancy and limiting their ability to capture sub-daily variability. This study addresses these limitations using deep learning (DL) algorithms to model hourly surges simultaneously at multiple tide gauges along the U.S. East Coast and Gulf of Mexico. Three algorithms, Convolutional Neural Network (CNN), Long Short-Term Memory (LSTM), and a hybrid ConvLSTM are employed to model surges using …

An Integrated Study Of Aerosol Concentrations And Meteorological Conditions In El Paso Airshed Using Modeling And Instrumentation, Joscelyne Guzman-Gonzalez

Open Access Theses & Dissertations

Atmospheric aerosols are solid or liquid particles suspended in the atmosphere. Aerosols can be primary, which are directly emitted into the atmosphere, or secondary, which are formed when emitted gases undergo complex chemical reactions. Atmospheric aerosols can range from a few nanometers to tens of microns in diameter. Atmospheric aerosols play a significant role in climate; they can absorb or reflect heat, influencing temperature and weather patterns. Air quality is also affected by aerosols, which can have detrimental effects on human health, contributing to respiratory issues and other health problems. El Paso Texas is located at the south of the …

Spatial Gap-Filling Of Himawari-8 Hourly Aod Products Using Machine Learning With Model-Based Aod And Meteorological Data: A Focus On The Korean Peninsula, Youjeong Youn, Seoyeon Kim, Seung Hee Kim, Yangwon Lee

Institute for ECHO Articles and Research

Given the complex spatiotemporal variability of aerosols, high-frequency satellite observations are essential for accurately mapping their distribution. However, optical remote sensing encounters difficulties in detecting Aerosol Optical Depth (AOD) over cloud-covered regions, creating data gaps that limit comprehensive environmental analysis. This study introduces a spatial gap-filling method for Himawari-8/Advanced Himawari Imager (AHI) hourly AOD data, using a Random Forest (RF) model that integrates meteorological variables and model-based AOD data. Developed and validated over South Korea from 1 January to 31 December 2019, the model effectively improved data coverage from 6% to 100%. The approach demonstrated high performance in blind tests, …

Climatological Trends And Effects Of Aerosols And Clouds On Large Solar Parks: Application Examples In Benban (Egypt) And Al Dhafrah (Uae), Harshal Dhake, Panagiotis Kosmopoulos, Antonis Mantakas, Yashwant Kashyap, Hesham El-Askary, Omar Elbadawy

Mathematics, Physics, and Computer Science Faculty Articles and Research

Solar energy production is vastly affected by climatological factors. This study examines the impact of two primary climatological factors, aerosols and clouds, on solar energy production at two of the world’s largest solar parks, Benban and Al Dhafrah Solar Parks, by using Earth observation data. Cloud microphysics were obtained from EUMETSAT, and aerosol data were obtained from the CAMS and assimilated with MODIS data for higher accuracy. The impact of both factors was analysed by computing their trends over the past 20 years. These climatological trends indicated the variations in the change in each of the factors and their resulting …

Predicting Cloud-To-Ground Lightning In The Western United States From The Large-Scale Environment Using Explainable Neural Networks, Dmitri A. Kalashnikov, Frances V. Davenport, Zachary M. Labe, Paul C. Loikith, John T. Abatzoglou, Deepti Singh

Geography Faculty Publications and Presentations

Lightning is a major source of wildfire ignition in the western United States (WUS). We build and train convolutional neural networks (CNNs) to predict the occurrence of cloud-to-ground (CG) lightning across the WUS during June-September from the spatial patterns of seven large-scale meteorological variables from reanalysis (1995-2022). Individually trained CNN models at each 1° × 1° grid cell ( = 285 CNNs) show high skill at predicting CG lightning days across the WUS (median AUC = 0.8) and perform best in parts of the interior Southwest where summertime CG lightning is most common. Further, interannual correlation between observed and predicted …

Lengthening Atlantic Hurricane Seasons With Earlier Storm Formation Dates Including Implications From 2020, Barry D. Keim, L. C. Hamilton, V. M. Brown, P. J. Klotzbach, A. B. Lewis, D. T. Thompson

School of Public Health Faculty Publications

This paper analyzes the formation dates of the nth storm in a sequence for all named North Atlantic tropical cyclones (TCs) and assesses whether the intraseasonal length of the Atlantic hurricane season has changed temporally. The record-breaking 2020 season, with 30 named storms, set records for the earliest third TC formation (Cristobal) and from the sixth TC (Fay) onward. Analysis of season length from 1851 to 2022 identifies only one statistically significant breakpoint detected in the early 1970s, roughly coinciding with the introduction of satellite observations. Since 1970, we also find a trend toward longer North Atlantic hurricane seasons. The …

Global Empirical Model Of Sporadic-E Occurrence Rates, Eli V. Parsch, Anthony L. Franz, Eugene V. Dao, Dong L. Wu, Nimalan Swarnalingam, Cornelius C. J. H. Salinas, Daniel J. Emmons

Faculty Publications

Intense ionization enhancements in the Earth’s ionosphere, known as sporadic-E (E_s), can degrade and severely disrupt the propagation of radio signals. Although many previous studies have analyzed the characteristics and morphologies of sporadic-E, few efforts have attempted to model global E_s occurrence rates (ORs) at high time resolutions. This study develops a global empirical model of blanketing sporadic-E occurrence rates using a Karhunen–Loéve Expansion (KLE) of a global OR climatology built with Global Navigation Satellite System radio occultation (GNSS-RO) and ionosonde observations. Using an fbE ≥ threshold of 3 MHz, the model outputs a blanketing sporadic-E …

Typology Of Atmospheric Conditions Leading To Dam Overtopping In The Eastern Us, Hodo I. Orok, Deanna Hence

I-GUIDE Forum

Statistical characterization of reanalysis datasets during over 300 hydrologic dam incidents between 2003 and 2022 will create a detailed typology of weather systems associated with dam overtopping in the eastern United States. Dam overtopping poses significant risks to infrastructure and public safety, necessitating a comprehensive understanding of the multi-scale atmospheric conditions that lead to such events. To better account for the natural flow of water to the affected dams, we will adopt a watershed-focused Principal Component Analysis (PCA) on regional atmospheric data collected from ERA5 alongside USGS streamflow and Stage IV precipitation observations to enhance understanding of high-risk weather conditions. …

Creating Sustainable School And Home Gardens: Using Weather Stations, Jake Sanders, Daniel Findlay, Kathy Cabe Trundle, Rita Hagevik, Kaitlin Campbell

All Current Publications

This fact sheet provides an overview of how weather stations work and the steps to set up your own weather station. To help monitor the water conditions, wind speeds, and temperatures that can impact your plants, we suggest adding a weather station to your garden area or greenhouse.

Climate Prediction Center Analogs As Extended Range Predictors For Severe Convective Storms, Sean Phipps

Honors Capstones

Increasing the predictability of severe convective storms (SCSs) over extended time ranges (i. e. >8 days) is of utmost importance to forecasters, as modern numerical weather prediction (NWP) models exhibit little skill at this lead time. Analogs have been used to predict temperature and rainfall anomalies at this time range for decades, though modern developments in analog forecasting uses techniques such as analog ensembles to increase the skill of analog models. This study employs a simple analog ensemble (AnEn) method using the Climate Prediction Center (CPC) 6-10 Day 500hPa analogs and uses the Storm Prediction Center (SPC)’s report database to …

Managing Frost Risk, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Frost occurs on clear nights in early spring when the air temperature drops to 2°C or less. Crop damage from frost may occur at any stage of development but is most damaging at or around flowering.

Frost is difficult to manage, and damage will be unavoidable in some seasons. Risk management options proven to reduce frost risk include paddock zoning, crop and variety selection, time of sowing, stubble management and managing inputs. The greatest gains result from in paddock choice/zoning, crop and variety choice, and manipulating the canopy.

Methane Fluxes In Tidal Marshes Of The Conterminous United States, Ariane Arias-Ortiz, Jaxine Wolfe, Scott D. Bridgham, Sara Knox, Gavin Mcnicol, Brian A. Needelman, Julie Shahan, Ellen J. Stuart-Haëntjens, Lisamarie Windham-Myers, Patty Y. Oikawa, Dennis D. Baldocchi, Joshua S. Caplan, Margaret Capooci, Kenneth M. Czapla, R. Kyle Derby, Heida L. Diefenderfer, Inke Forbrich, Gina Groseclose, Jason K. Keller, Cheryl Kelley, Amir E. Keshta, Helena S. Kleiner, Ken W. Krauss, Robert R. Lane, Sarah Mack, Serena Moseman-Valtierra, Thomas J. Mozdzer, Peter Mueller, Scott C. Neubauer, Genevieve Noyce, Katrina V. R. Schäfer, Rebecca Sanders-Demott, Charles A. Schutte, Rodrigo Vargas, Nathaniel B. Weston, Benjamin Wilson, J. Patrick Megonigal, James R. Homquist

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Methane (CH4) is a potent greenhouse gas (GHG) with atmospheric concentrations that have nearly tripled since pre-industrial times. Wetlands account for a large share of global CH4 emissions, yet the magnitude and factors controlling CH4 fluxes in tidal wetlands remain uncertain. We synthesized CH4 flux data from 100 chamber and 9 eddy covariance (EC) sites across tidal marshes in the conterminous United States to assess controlling factors and improve predictions of CH4 emissions. This effort included creating an open-source database of chamber-based GHG fluxes (https://doi.org/10.25573/serc.14227085). Annual fluxes across chamber and EC sites averaged 26 ± 53 g CH4 …

Numerical Techniques For Improving Simulations Of Tropical Cyclones, Yassine Tissaoui

Dissertations

The increasing frequency and intensity of tropical cyclones (TCs) due to climate change pose significant challenges for forecasting and mitigating their impacts. Despite advancements, accurately predicting TC rapid intensification (RI) remains a challenge. Large eddy simulation (LES) allows for explicitly resolving the large eddies involved in TC turbulence, thus providing an avenue for studying the mechanisms behind their intensification and RI. LES of a full tropical cyclone is very computationally expensive and its accuracy will depend on both explicit and implicit dissipation within an atmospheric model. This dissertation presents two novel numerical methodologies with the potential to improve the efficiency …

Coastal Sedimentary Records Of Extreme Events And Human Activity: Examples From Hurricanes And Microplastics, Nicholas T. Culligan

LSU Doctoral Dissertations

Coastal regions are uniquely vulnerable to a myriad of natural and anthropogenically caused stresses such as hurricane strikes and chronic microplastic pollution. Both hurricanes and microplastics have major negative effects on global coastlines and are forecast to become more damaging in the future. However, current model trends are based on limited modern data and may not provide an accurate or comprehensive view of the future. Therefore, this dissertation investigates coastal stratigraphic records to determine long-term past trends of these presses and pulses so that researchers, stakeholders, and policy makers can use them to enact strategies to mitigate damages from worsening …

Open-Loop Wavefront Sensing In The Presence Of Speckle And Weak Scintillation, Derek J. Burrell, Mark F. Spencer, Ronald G. Driggers

Faculty Publications

In this paper, we show that speckle averaging helps to reduce the measurement error associated with a Shack–Hartmann wavefront sensor (SHWFS); however, this reduction is rendered ineffective with increasing beacon anisoplanatism. We do so operating in a weak-scintillation regime, where the SHWFS offers robust performance, and using in-plane translation of the illuminated rough surface to accomplish frame-to-frame speckle diversity. Understanding these trade-space limitations is critical when performing wavefront sensing with noncooperative, extended-source beacons.

Further Developing Drought Early Warning Information Systems Using Mixed-Methods And Multiple Streams Of Data, Caily Claire Schwartz

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Drought is a complex phenomenon with varying degrees of impacts and monitoring methods. No drought is alike, creating a challenge for both water managers and communities. No area is immune to a drought. Due to the cyclical nature of drought events, clear information to those impacted is necessary to reduce risk and move towards proactive responses, as opposed to reactive responses. To better provide communication and mitigation tools, Drought Early Warning Information Systems (DEWIS) have been developed in various regions and contexts. To improve early warning, an understanding of the end user’s perceptions of risk, and the applicability of data …

Sensitivity Of Present And Future Seasonal Precipitation Over Central United States To The Representation Of Rocky Mountain Topography, Ranasinghe Disanayakalage Sherly Shelton Ranathunga

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Precipitation change across the Central United States (USA) is of great interest to the research community. Studies using global climate simulations suggest that the “100^th-Meridian”, which separates the “dry west” from the “moist east” will shift to the east as the climate responds to future emissions pathways. However, these simulations are run at relatively coarse resolutions, which do not accurately represent topography. Here, we perform regional simulations using the Weather Research and Forecasting (WRF) model to explore the sensitivity of present and future precipitation patterns across the central USA to the representation of the Rocky Mountains (RM). We …

Role Of Planetary Wave-Tide-Gravity Wave Interactions In Whole Atmosphere Coupling, Zishun Qiao

Doctoral Dissertations and Master's Theses

This dissertation investigates the mechanism by which the Earth's whole atmosphere couples from the bottom to the top, pole to pole. The work in this dissertation utilizes observational data and numerical simulations, with a particular emphasis on sudden stratospheric warming (SSW) events. The development of a new multi-static meteor radar at 30ºS, named Chilean Observation Network De MeteOr Radars (CONDOR), provides a key dataset for the present studies. Wind validation of this new radar system is performed across different sites and compared to a co-located sodium lidar. Wave-wave interactions in the mesosphere and lower thermosphere (MLT) that may be responsible …

Ocean Temperatures Do Not Account For A Record-Setting Winter In The U.S. West, Matthew D. Laplante, Liping Deng, Luthiene Dalanhese, Shih-Yu Wang

Journalism and Communication Faculty Publications

The record-setting winter of 2022–2023 came as an answer to both figurative and literal prayers for political leaders, policy makers, and water managers reliant on snowpacks in the Upper Colorado River Basin, a vital source of water for tens of millions of people across the Western United States. But this “drought-busting” winter was not well-predicted, in part because while interannual patterns of tropical ocean temperatures have a well-known relationship to precipitation patterns across much of the American West, the Upper Colorado is part of a liminal region where these connections tend to be comparatively weak. Using historical sea surface temperature …