Atmospheric Sciences Commons^™

Volumetric Reconstruction Of Ionospheric Electric Currents From Tri-Static Incoherent Scatter Radar Measurements, Jone Peter Reistad, Spencer Mark Hatch, Karl M. Laundal, Kjellmar Oksavik, Matthew David Zettergren, Heikki Vanhamaki, Ilkka I. Virtanen

Publications

We present a new technique for the upcoming tri-static incoherent scatter radar system EISCAT 3D (E3D) to perform a volumetric reconstruction of the 3D ionospheric electric current density vector field, focusing on the feasibility of the E3D system. The input to our volumetric reconstruction technique are estimates of the 3D current density perpendicular to the main magnetic field, $\mathbf{j} \perp$, and its co-variance, to be obtained from E3D observations based on two main assumptions: 1) Ions fully magnetised above the $E$ region, set to 200 km here. 2) Electrons fully magnetised above the base of our domain, set to 90 …

The 2022 Hunga Tonga Volcanic Eruption's Impact On Radio Communications, Spencer Brothers

Student Research Symposium

On January 15^th 2022, the Hunga Tonga volcanic eruption, Figure 1, ejected unprecedented amounts of water into the stratosphere. The resulting plume may present temporary opportunities for long distance radio communication.

Nowcasting Heavy Rainfall With Convolutional Long Short-Term Memory Networks: A Pixelwise Modeling Approach, Yi Victor Wang, Seung Hee Kim, Geunsu Lyu, Choeng-Lyong Lee, Soorok Ryu, Gyuwon Lee, Ki-Hong Min, Menas C. Kafatos

Institute for ECHO Articles and Research

The recent decades have seen an increasing academic interest in leveraging machine learning approaches to nowcast, or forecast in a highly short-term manner, precipitation at a high resolution, given the limitations of the traditional numerical weather prediction models on this task. To capture the spatiotemporal associations of data on input variables, a deep learning (DL) architecture with the combination of a convolutional neural network and a recurrent neural network can be an ideal design for nowcasting rainfall. In this study, a long short-term memory (LSTM) modeling structure is proposed with convolutional operations on input variables. To resolve the issue of …

Error Analysis Of Numerical Weather Prediction Forecasts And Remotely Sensed Air Properties, Caleb R. Sease

Honors Theses

Communication and sensing technologies are influenced by atmospheric properties such as the air’s index of refraction, humidity, and temperature in the marine atmospheric surface layer (MASL). Recent research has demonstrated that radar can remotely sense the index of refraction in the MASL and, sometimes, numerical weather prediction models (NWP) can be used to aid this process. These developments are important because they allow for larger spatial coverage and finer temporal resolution than is possible with in-situ atmospheric sensors. More recently, on-going research is working toward extending this remote sensing capability to humidity using refraction as an intermediary. In order to …

Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform, Joshua W. Milford

Doctoral Dissertations and Master's Theses

Low-cost and low-size-weight-and-power (SWaP) magnetometers can provide greater accessibility for distributed simultaneous measurements in the ionosphere, either onboard sounding rockets or on CubeSats. The Space and Atmospheric Instrumentation Laboratory (SAIL) at Embry-Riddle Aeronautical University has launched a multitude of sounding rockets in recent history: one night-time mid-latitude rocket from Wallops Flight Facility in August 2022 and three mid-latitude rockets from White Sands Missile Range during the October 2023 annular solar eclipse. All rockets had a comprehensive suite of instruments for electrodynamics and neutral dynamics measurements. Among this suite was one science-grade three-axis fluxgate magnetometer (Billingsley TFM65VQS / TFM100G2) and up …

Spectroscopy Of Atmospheres, Randika Dodangodage

Physics Theses & Dissertations

Spectroscopic methods are used to study planetary and stellar atmospheres. The information obtained from spectroscopic studies provides insight into atmospheric compositions and dynamics, which can be used to model and characterize atmospheres and climates. Laboratory-recorded absorption cross-sections are needed to interpret the recorded spectra of planets and stars. High resolution ethane, neopentane, propene, and n-butane spectra have been recorded, and absorption cross-sections have been provided for different temperatures and total pressures with different broadening gases, including hydrogen, helium, and nitrogen. The Atmospheric Chemistry Experiment (ACE) satellite orbits Earth and records spectra through solar occultation limb observations. HOCl is a chlorine …

Interferometric Imaging With Eiscat_3d For Fine-Scale In-Beam Incoherent Scatter Spectra Measurements, M. Zettergren, Devin Huyghebaert, Björn Gustavsson, Juha Vierinen, Andreas Kvammen, John Swoboda, Ilkka Virtanen, Spencer Hatch, Karl M. Laundal

Publications

The 233 MHz EISCAT_3D radar system currently under construction in northern Fennoscandia will be able to resolve ionospheric structures smaller than the transmit beam dimensions through the use of interferometric imaging. This capability is made possible by the modular design and digitization of the 119 91-antenna panels located at the main Skibotn site. The main array consists of a cluster of 109 panels, with 10 outlier panels producing unique interferometry baselines. In the present study synthesized incoherent scatter radar signal measurements are used for interferometric imaging analysis with the EISCAT_3D system. The Geospace Environment Model of Ion-Neutral Interactions (GEMINI) model …

Ground Electric Field, Atmospheric Weather And Electric Grid Variations In Northeast Greece Influenced By The March 2012 Solar Activity And The Moderate To Intense Geomagnetic Storms, Georgios Anagnostopoulos, Anastasios Karkanis, Athanasios Kampatagis, Panagiotis Marhavilas, Sofia-Anna Menesidou, Dimitrios Efthymiadis, Stefanos Keskinis, Dimitar Ouzounov, Nick Hatzigeorgiu, Michael Danakis

Mathematics, Physics, and Computer Science Faculty Articles and Research

In a recent paper, we extended a previous study on the solar solar influence to the generation of the March 2012 heatwave in the northeastern USA. In the present study we check the possible relationship of solar activity with the early March 2012 bad weather in northeast Thrace, Greece. To this end, we examined data from various remote sensing instrumentation monitoring the Sun (SDO satellite), Interplanetary space (ACE satellite), the Earth’s magnetosphere (Earth-based measurements, NOAA-19 satellite), the top of the clouds (Terra and Aqua satellites), and the near ground atmosphere. Our comparative data analysis suggests that: (i) the winter-like weather …

Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density, Natalie R. Wirth

Theses and Dissertations

High frequency (HF) communication is a vital aspect of military communication and is highly reliant upon ionospheric conditions. The variation in electron density within the lowest echelon of the ionosphere, the D-region, can significantly impact HF signals, making communication inconsistent and unreliable for these wavelengths. Despite the D-region’s important, research in this area mainly focuses on understanding the impact of space weather anomalies on the upper ionosphere, particularly its higher layers, with relatively little exploration of the D-region. This region, situated closest to the troposphere and stratosphere, has been definitively linked to solar weather events like solar flares and geomagnetic …

Global Empirical Model Of Sporadic-E Occurrence Rates, Eli V. Parsch

Theses and Dissertations

Encompassing the Earth, the ionosphere presents unique challenges to modern communication, navigation, and surveillance technologies. Intense ionization enhancements known as sporadic-E (Es), can degrade and disrupt signals in unpredictable ways. Much work has been done to understand this phenomenon and more recent efforts have attempted to model its behavior and impacts. However, there have been limited efforts at modeling global Es occurrence rates (OR) at high time resolutions. This study develops a global empirical model of blanketing sporadic-E (fbEs) occurrence rates using a Karhunen-Lo´eve Expansion (KLE) of global fbEs OR climatologies built with Global Positioning System radio occultations (GPS-RO) and …

Modeling Lightning Flashes In Dissimilar Non-Homogeneous Clouds, Scott R. Wolff

Theses and Dissertations

A new methodology for near-infrared lightning radiative transfer through clouds is presented. High-resolution weather modeling is used to generate realistic three-dimensional non-homogeneous clouds, which are then used as environments for a Monte Carlo simulation of photon multiple scattering from approximations of lightning flashes. Resultant emissions from the cloud tops are in line with previous studies and satellite observations.

Investigation Of High-Latitude Gnss Radio Occulation Sporadic-E And Auroral-E Measurements, Kyle D. Roberts

Theses and Dissertations

Abnormal sporadic-E (E_s) occurrences were found in the high latitude regions during a recent climatology study by (Hodos, 2022), that calculated sporadic-E occurrence rates derived from a data set of GPS radio occultation (GPS-RO) and ionosondes. In this study, sporadic-E GNSS-RO techniques are shown to falsely attribute sporadic-E events to auroral-E (E_a) events. A comparative study is conducted on GPS-RO measurement techniques to find false occurrence rates for various RO techniques using a single ionosonde site in Gakona, Alaska. Phase-based RO techniques were found to be more likely to falsely attribute sporadic-E as auroral-E, while amplitude …

Low-Temperature Laboratory Instrumentation For Investigating Ice Crystal Aggregate Formation In The Atmosphere, Victor Ojo, Imteaz Osmani, Hallie Boyer Chelmo

Graduate Research Achievement Day Posters

This study addresses the challenge of achieving controlled low temperatures to investigate and provide information on the precise conditions that promote homogenous (≤-38oC) and heterogenous (≥ -38oC) atmospheric ice crystal formation and aggregation, which disrupt aerospace industries and military activity. I present a preliminary design of a novel temperature control setup for generating levitated ice crystal aggregates within a Dual Balance Electrodynamic Trap (DBET). This preliminary design is called the replica low temperature electrodynamic balance (R-LTDBET). The design integrates chilled-coolant-conveying copper tubes encircling the hollow-square-shaped DBET’s external wall to precisely control its inner chamber temperature while incorporating real-time temperature sensing, …

Analyzing The Effects Of Data Variability & Volume On Predicting Particulate Matter (Pm2.5): Insights From A Machine Learning Approach, Jada A. Macharie

Theses and Dissertations

Accurately predicting PM_2.5 concentrations are imperative to the future of public health and environmental policies. Machine learning models incorporating spatial and temporal datasets to predict PM_2.5 are often limited by data availability constraints and poor resolution satellite imagery.

Application Of Remote Sensing And Spectroradiometry In Geological Mapping: A Case Study Of Handeni (Qds 148) Block, Eastern Mozambique Belt, Tanzania, Masota M. Magigita, Elisante Mshiu, Cassy Mtelela

Tanzania Journal of Science

This study applies remote sensing (RS) as a geologic mapping aid tool , using Handeni Block of Tanzania as a case study. To achieve the objective of this study, we have utilized various RS processing and image enhancement techniques on multispectral data, including ASTER, Landsat 5, Landsat 8, and Sentinel 2A. The method proved successful whereby both Landsat-5-data with band combination (BC) 7:4:2 and 7:5:4 and band ratio (BR) 5/3:5/1:7/5 and Landsat-8 data with BCs 5:6:7 and 7:6:4 mapped out marble units. Sentinel 2A data (with BC 8:11:3, BRs 12/2:11/2:8/11; 12/4:11/3:11/2 and 12/4:12/2:11/3) together with image enhancement decorrelation stretch on …

Effect Of Substrate Temperature And Deposition Power On The Surface Morphology And Optical Properties Of Zno:Mg Thin Films Deposited By Dc Magnetron Sputtering, Saidi Saidi, Margaret E. Samiji, Nuru R. Mlyuka

Tanzania Journal of Science

Magnesium doped zinc oxide (ZnO:Mg) thin films were deposited on soda lime glass slides by DC magnetron sputtering method. Atomic force microscope (AFM), and UV/VIS spectrophotometer were used to investigate the effect of sputtering power and substrate temperature on the surface morphology and optical properties of ZnO:Mg thin films. AFM images revealed that sputtering power and deposition temperature have significant influence on surface morphology of the ZnO:Mg thin films. For all sputtering powers and substrate temperatures investigated, ZnO:Mg films had peak transmittance above 85%. Samples deposited at 110 W sputtering power and 450 °C substrate temperature showed the best peak …

Quantifying The Strength Of The El Niño Southern Oscillation And The Indian Ocean Dipole In Influencing The Ond Rainfall Season In Tanzania, Benjamin William Ongito, Paul T.S. Limbu

Tanzania Journal of Science

The current paper examines the strength of variability between the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) in influencing October to December (OND) rainfall over the bimodal rainfall regime of Tanzania. The empirical orthogonal function (EOF), correlation analysis, and composite analysis were used during the data analysis. The results show more rainfall distribution over the western part of the Lake Victoria basin and to the peripheral of the northern coast of the country, thus suggesting that, during the OND rainfall season, the onset starts in the western part of the Lake Victoria basin, then spreads to the …

The Effects Of Wildfire Aerosol Emissions On Air Quality, Emma Braun, Audrey Shirley

The Journal of Purdue Undergraduate Research

No abstract provided.

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 …

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.

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 …

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 …