Open Access. Powered by Scholars. Published by Universities.®

Oceanography and Atmospheric Sciences and Meteorology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Atmospheric Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 211 - 240 of 2458

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation, Emmanuel Ogwuche Audu May 2024

Understanding The Zonal Variability In Cmip6 Projections Of Sahelian Precipitation, Emmanuel Ogwuche Audu

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

The uncertainty in model projections of future precipitation across the Sahel has persisted across many generations of Earth System Models (ESMs), with some models predicting drying and others moistening across this region. These discrepancies in future projections pose a challenge for stakeholders and decision makers. Many projections of Sahel precipitation found in the ESMs participating in the sixth phase of Coupled Model Intercomparison Project (CMIP6) show a zonal dipole in precipitation trend, with moistening across the Central and Eastern Sahel and drying projected for the Western Sahel. Previous studies have connected precipitation variability across the Sahel to changes in various …

Go to article

Polarimetric Radar Signatures In Significant Severe Left-Moving Supercells, Raychel Nelson May 2024

Polarimetric Radar Signatures In Significant Severe Left-Moving Supercells, Raychel Nelson

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

Left-moving (LM) supercells, though rarer than right-moving (RM) supercells, may produce significant severe weather. However, there are very few existing studies on LM supercells, particularly polarimetric radar analyses. The upgrade of the nationwide Weather Surveillance Radar-1988 Doppler (WSR-88D) network to polarimetric capability and subsequent studies vastly improved understanding of RM supercells, but similar efforts have largely not been made for LM supercells. This study employs an automated polarimetric radar signature detection algorithm to examine a dataset of significant severe (hail ≥ 2.00”, wind ≥ 65 kts) LM supercells to quantify their polarimetric signatures. Comparisons are made with RM supercells to …

Go to article

A Dual-Polarimetric Analysis Of A Large Sample Of Left-Moving Supercells, Ben Schweigert May 2024

A Dual-Polarimetric Analysis Of A Large Sample Of Left-Moving Supercells, Ben Schweigert

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

Supercells have been researched extensively since they were first described over 50 years ago. They are prolific severe weather producers, responsible for the most severe hail, severe wind gusts, and tornadoes. These rotating thunderstorms require attention from forecasters to protect life and property from their threats, most effectively done with Doppler radars. While extensive amounts of radar-based investigations have been completed, they focused almost exclusively on right-moving (RM) supercells, resulting in a knowledge gap surrounding their counter-rotating (left-moving, LM) partners. This study works to fill the void by developing a dataset of LM supercells and analyzing the dual-polarimetric features observed …

Go to article

The Impacts Of Wind On Coastal Trees, Julian Halil May 2024

The Impacts Of Wind On Coastal Trees, Julian Halil

All Theses

Trees in hurricane-prone areas are exposed to severe winds and flooding. We studied the physiological and structural responses of forested wetland trees in relation to wind stress. We evaluated the windfirmness of two forested wetland tree species. Baldcypress was chosen because of high survival in post-hurricane studies. In contrast, laurel oak co-occurs with baldcypress yet resists hurricane-force winds poorly. In a static winching study, we quantified the critical turning moment (Mcrit) required to topple both species. Mcrit increased with trunk diameter at breast height (DBH) and crown size. Baldcypress and laurel oak demonstrated similar Mcrit, but regression models indicate baldcypress …

Go to article

Geomagnetic Substorms Prediction Model Using Combined Physics-Based And Deep Learning Modeling Techniques, Ruthba Yasmin May 2024

Geomagnetic Substorms Prediction Model Using Combined Physics-Based And Deep Learning Modeling Techniques, Ruthba Yasmin

Graduate Theses and Dissertations (2019 - present)

This thesis aims to develop a hybrid physics-incorporated neural network model (PINN) for classifying geomangnetic substorms in Earth's Magnetosphere. The model is trained using a comprehensive list of substorm onsets, ground magentometer data from a global network, and solar wind parameters from the Advanced Composition Explorer (ACE) satellite. Two different neural network architectures are used, and the physics model used for training is called WINDMI. The magnetic field components on the ground, which are a function of the ionospheric currents, are captured by the SML index. The methodology involves using 60-minute data segments preceding an event to train the hybrid …

Go to article

Deterministic Global 3d Fractal Cloud Model For Synthetic Scene Generation, Aaron M. Schinder, Shannon R. Young, Bryan J. Steward, Michael L. Dexter, Andrew Kondrath, Stephen Hinton, Ricardo Davila May 2024

Deterministic Global 3d Fractal Cloud Model For Synthetic Scene Generation, Aaron M. Schinder, Shannon R. Young, Bryan J. Steward, Michael L. Dexter, Andrew Kondrath, Stephen Hinton, Ricardo Davila

Faculty Publications

This paper describes the creation of a fast, deterministic, 3D fractal cloud renderer for the AFIT Sensor and Scene Emulation Tool (ASSET). The renderer generates 3D clouds by ray marching through a volume and sampling the level-set of a fractal function. The fractal function is distorted by a displacement map, which is generated using horizontal wind data from a Global Forecast System (GFS) weather file. The vertical windspeed and relative humidity are used to mask the creation of clouds to match realistic large-scale weather patterns over the Earth. Small-scale detail is provided by the fractal functions which are tuned to …

Go to article

Angular Distribution Of Bremsstrahlung Spectral Temperature Measured In A Full Dimension Of Ecr Ion Source Using Nai(Ti) Detector, Mwingereza J. Kumwenda Apr 2024

Angular Distribution Of Bremsstrahlung Spectral Temperature Measured In A Full Dimension Of Ecr Ion Source Using Nai(Ti) Detector, Mwingereza J. Kumwenda

Tanzania Journal of Science

Measurement of angular distribution (AD) of the bremsstrahlung spectral temperature from a full dimension of the Electron Cyclotron Resonance Ion Source (ECRIS) along the beam axis is challenging. To overcome some challenges, this paper presents the AD of the bremsstrahlung spectral temperature measured in a full dimension of the ECRIS along the beam axis using data obtained from the Busan Center of Korea Basic Science Institute (KBSI). The bremsstrahlung spectral temperature from 28-GHz ECR Ion source at the KBSI was measured in six, three, and nine azimuthal angles at the injection, centre, and extraction sides of the ECRIS using three …

Go to article

Investigating Turbulence Distribution In The Lower Atmosphere Using Time-Lapse Imagery From A Camera Bank, Benjamin C. Wilson, Santasri R. Bose-Pillai, Jack E. Mccrae, Steven T. Fiorino, Robert P. Freeman, Laura R. Slabaugh Apr 2024

Investigating Turbulence Distribution In The Lower Atmosphere Using Time-Lapse Imagery From A Camera Bank, Benjamin C. Wilson, Santasri R. Bose-Pillai, Jack E. Mccrae, Steven T. Fiorino, Robert P. Freeman, Laura R. Slabaugh

Faculty Publications

The atmosphere’s surface layer (first 50–100 m above the ground) is extremely dynamic and is influenced by surface radiative properties, roughness, and atmospheric stability. Understanding the distribution of turbulence in the surface layer is critical to many applications, such as directed energy and free space optical communications. Several measurement campaigns in the past have relied on weather balloons or sonic detection and ranging (SODAR) to measure turbulence up to the atmospheric boundary layer. However, these campaigns had limited measurements near the surface. We have developed a time-lapse imaging technique to profile atmospheric turbulence from turbulence-induced differential motion or tilts between …

Go to article

A Climatology Of North American Monsoon Precipitation Over Arizona From Mrms Data, Greta Graeler, Mark Sinclair, Curtis N. James Apr 2024

A Climatology Of North American Monsoon Precipitation Over Arizona From Mrms Data, Greta Graeler, Mark Sinclair, Curtis N. James

Publications

The North American Monsoon (NAM) is a seasonal shift in pressure and wind which accounts for over half of the southwest’s annual precipitation. North-central Arizona has variable terrain which influences the location and intensity of convective storms. Severe weather such as strong winds, lightning, and hail can cause loss of life, property, and fires. High spatial and temporal resolution data along with reanalysis data is used to identify convective cells and their motion for the 2015 to 2022 NAM seasons. The heaviest precipitation in north-central Arizona is found over the Bradshaw Mountains and is most active in July and August. …

Go to article

Investigation Of Surface Chemistry From Electron Irradiation Of Synthetic Schreibersite, Tyler Davis Apr 2024

Investigation Of Surface Chemistry From Electron Irradiation Of Synthetic Schreibersite, Tyler Davis

Master's Theses

While phosphorus is one of the key elements for life on Earth, it has relatively low abundance in extraterrestrial environments, making it a target for astronomers and astrobiologists interested in the possibility of life beyond our planet. Schreibersite (Fe,Ni)3P is one of the first P-containing minerals to condense during planetary cooling and one of the primary P-containing minerals in iron and stony-iron meteorites. Therefore, it is a likely P-bearing mineral in cometary cores and dust grains within the interstellar medium and circumstellar envelopes. Experiments in this project were performed with the aim of observing the formation of small …

Go to article

Kinematic And Dynamic Structure Of The 18 May 2020 Squall Line Over South Korea, Wishnu Agum Swastiko, Chia-Lun Tsai, Seung Hee Kim, Gyuwon Lee Apr 2024

Kinematic And Dynamic Structure Of The 18 May 2020 Squall Line Over South Korea, Wishnu Agum Swastiko, Chia-Lun Tsai, Seung Hee Kim, Gyuwon Lee

Institute for ECHO Articles and Research

The diagonal squall line that passed through the Korean Peninsula on the 18 May 2020 was examined using wind data retrieved from multiple Doppler radar synthesis focusing on its kinematic and dynamic aspects. The low-level jet, along with warm and moist air in the lower level, served as the primary source of moisture supply during the initiation and formation process. The presence of a cold pool accompanying the squall line played a role in retaining moisture at the surface. As the squall line approached the Korean Peninsula, the convective bands in the northern segment (NS) and southern segment (SS) of …

Go to article

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 Apr 2024

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 …

Go to article

The 2022 Hunga Tonga Volcanic Eruption's Impact On Radio Communications, Spencer Brothers Apr 2024

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

Student Research Symposium

On January 15th 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.

Go to article

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 Apr 2024

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 …

Go to article

Spectroscopy Of Atmospheres, Randika Dodangodage Apr 2024

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 …

Go to article

Error Analysis Of Numerical Weather Prediction Forecasts And Remotely Sensed Air Properties, Caleb R. Sease Apr 2024

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 …

Go to article

Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform, Joshua W. Milford Apr 2024

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 …

Go to article

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 Mar 2024

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 …

Go to article

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 Mar 2024

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 …

Go to article

Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density, Natalie R. Wirth Mar 2024

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 …

Go to article

Global Empirical Model Of Sporadic-E Occurrence Rates, Eli V. Parsch Mar 2024

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 …

Go to article

Investigation Of High-Latitude Gnss Radio Occulation Sporadic-E And Auroral-E Measurements, Kyle D. Roberts Mar 2024

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

Theses and Dissertations

Abnormal sporadic-E (Es) 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 (Ea) 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 …

Go to article

Modeling Lightning Flashes In Dissimilar Non-Homogeneous Clouds, Scott R. Wolff Mar 2024

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.

Go to article

Low-Temperature Laboratory Instrumentation For Investigating Ice Crystal Aggregate Formation In The Atmosphere, Victor Ojo, Imteaz Osmani, Hallie Boyer Chelmo Feb 2024

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, …

Go to article

Analyzing The Effects Of Data Variability & Volume On Predicting Particulate Matter (Pm2.5): Insights From A Machine Learning Approach, Jada A. Macharie Jan 2024

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 PM2.5 concentrations are imperative to the future of public health and environmental policies. Machine learning models incorporating spatial and temporal datasets to predict PM2.5 are often limited by data availability constraints and poor resolution satellite imagery.

Go to article

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 Jan 2024

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 …

Go to article

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 Jan 2024

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 …

Go to article

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 Jan 2024

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 …

Go to article

The Effects Of Wildfire Aerosol Emissions On Air Quality, Emma Braun, Audrey Shirley Jan 2024

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

The Journal of Purdue Undergraduate Research

No abstract provided.

Go to article

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 Jan 2024

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 …

Go to article

First Prev Next Last