Atmospheric Sciences Commons^™

Stratospheric Glider Measurements Of Atmospheric Parameters, Anisa Haghighi

Theses and Dissertations--Mechanical and Aerospace Engineering

In June 2021 a series of high altitude flights were conducted in Spaceport America, NM, using a balloon launched Uncrewed Aircraft System (UAS) to assess its capability to conduct measurements of various atmospheric properties and study turbulence in the troposphere and lower stratosphere. This UAS descends using an automated flight trajectory. The instruments aboard included a NASA-developed infrasonic microphone to evaluate its remote turbulence detection capabilities and a five-hole probe capable of measuring the in situ wind vector. Also on board were temperature, humidity and wind profile sensors. This document focuses on the atmospheric properties measured at high altitudes, the …

Precision Meteorological Prediction Employing A Data-Driven, Adaptive, Real-Time (Dart) Approach, Sujit Sinha

Theses and Dissertations--Mechanical and Aerospace Engineering

The objective of this research is to improve precision meteorological prediction, benefiting both uncrewed aerial vehicle (UAV) operations by avoiding hazardous flight conditions and tracking contaminant or toxic clouds caused by incidents, accidents, or fires. The operational concept is to collect meteorological observations from instruments mounted on a swarm of UAVs, telemeter the data to a weather simulation model, revise the predicted solution by adapting the flow field to the observations, and then transmit the updated forecast to appropriate personnel as well as to the guidance system of UAVs for repositioning to the next set of most beneficial measurements. While …

Unmanned Aircraft Systems For Precision Meteorology: An Analysis Of Gnss Position Measurement Error And Embedded Sensor Development, Karla S. Ladino

Theses and Dissertations--Biosystems and Agricultural Engineering

The overarching objective of this research was to enhance our comprehension of the three-dimensional precision of meteorological measurements obtained using small unmanned aircraft systems (UAS). Two complimentary experiments were conducted to achieve this objective.

The first experiment entailed the development and implementation of a system to determine the global navigation satellite system (GNSS) position accuracy on a UAS platform. This system was utilized to assess the static and dynamic accuracy of L1 and L1/L2 GNSS receivers in real-time kinematic (RTK) and non-RTK fix modes. Adjusted two-sample t-tests revealed significant differences in horizontal and vertical error between RTK and non-RTK receivers …

Shallow Water Coral Distribution And Its Response To Climate Change, Amaury De Jesus

Dissertations and Theses

Shallow water corals are one of the main reef-building organisms that secrete carbonates as their skeletons, and therefore, are one of the major sinks of CO2 in the ocean. These reef builders are also very crucial to marine environments and human society. As the global energy demand continues rising, fossil fuel burning increases at a faster pace despite the increase in energy supply using clean and renewable energy. The increase of CO2 in the atmosphere has been shown to exacerbate global warming and may cause ocean acidification, threatening the habitat of shallow-water corals. Many recent observations show alarming signs of …

Spatial And Temporal Characteristics Of Historical Surface Climate Over The Northwest Territories, Canada, Bhaleka D. Persaud

Theses and Dissertations (Comprehensive)

Climate change is putting many of the Northwest Territories (NWT) ecosystems, its people and animal populations at risk due to accelerated warming, permafrost thaw, and changing precipitation regimes. As the NWT continues to warm, at disproportionately higher rates when compared to the rest of Canada, threats to the stability of NWT’s ecosystems are expected to increase. Consequently, understanding how climate warming has changed historically and its implications on natural ecosystems requires point-to-region-specific, long-term climatic data to elucidate important drivers of observed changes relevant to decision makers at community, Indigenous, Territorial and Federal government levels. However, in situ climate data are …

Physical, Optical, And Chemical Properties Of Light Absorbing Aerosols And Their Climatic Impacts, Susan Mathai

Dissertations, Master's Theses and Master's Reports

Aerosols are particles suspended in the atmosphere; they are emitted during natural phenomena such as dust storms, wildfires, and volcanic eruptions, and during anthropogenic activities like household wood burning, vehicles operations, and industrial productions, or they can form in the atmosphere from gas to particle partition. Aerosols impact earth’s weather and climate by absorbing and scattering the incoming solar and the outgoing earth thermal radiation and interacting with clouds. The optical properties of aerosols evolve as the chemical and physical properties vary during their residence in the atmosphere. In addition, the aerosols’ properties strongly depend on the vertical distribution in …

Large Cloud Droplets And The Initiation Of Ice By Pressure Fluctuations: Molecular Simulations And Airborne In-Situ Observations, Elise Rosky

Dissertations, Master's Theses and Master's Reports

From the molecular dynamics of water molecules to the global processes that control atmospheric circulation: describing the evolution of atmospheric clouds necessitates physics that spans vast spatial scales. In this work, steps are taken towards connecting the molecular physics of ice-nucleation to the growth and subsequent freezing of cloud droplets in convective cumulus clouds. Motivated by experimental evidence of ice nucleation triggered by agitation and distortion of a water droplet surface, the first study in this dissertation uses molecular dynamics simulations to demonstrate that negative Laplace pressure from a curved water surface leads to heterogeneous ice nucleation at higher temperatures. …

Perceived Barriers To Cervical Cancer Screening Among Hispanic Women, Damaris Perez

Walden Dissertations and Doctoral Studies

AbstractHispanic women are among the ethnic groups with higher cervical cancer rates in the United States. This mixed-method study was conducted to explore perceived barriers and self-efficacy-related factors to cervical cancer screening in foreign-born Hispanic women in Florida. The theory of planned behavior was applied to determine if behavioral intentions influence access to cervical cancer screening. The inclusion criteria included Hispanic women 18 years old and older without a hysterectomy history. Quantitative data were collected through a self-administered survey. A total of 84 individuals completed the survey. A binary logistic regression analysis was performed to determine if sociodemographic factors are …

Spatiotemporal Variability Of Drought And Its Relationships To Enso And Iod Indices In Somaliland, Mohamed S Bile, Paul Ts Limbu

Tanzania Journal of Science

Drought is one of Somaliland’s most prevalent natural hazards, causing serious socioeconomic and environmental harm. This study investigated the spatial and temporal variability of drought and its relationships with El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) indices using the Standardized Evapotranspiration Index (SPEI) from 1981 to 2020. The Mann-Kendall trend test and Sen's slope estimator were used to assess the trends of annual and seasonal SPEI time series. The Empirical Orthogonal Function (EOF) was employed to examine the dominant modes of the SPEI series, and Pearson and partial correlation analyses were performed to investigate the associations between …

Ecological Protection Alone Is Not Enough To Conserve Ecosystem Carbon Storage: Evidence From Guangdong, China, Lihan Cui, Wenwen Tang, Sheng Zheng, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The increase in atmospheric CO₂ caused by land use and land cover change (LUCC) is one of the drivers of the global climate. As one of the most typical high-urbanization areas, the ecological conflicts occurring in Guangdong Province warrant urgent attention. A growing body of evidence suggests LUCC could guide the future ecosystem carbon storage, but most LUCC simulations are simply based on model results without full consistency with the actual situation. Fully combined with the territorial spatial planning project and based on the land use pattern in 2010 and 2020, we have used the Markov and Patch-generating Land …

Possible Overestimation Of Nitrogen Dioxide Outgassing During The Beirut 2020 Explosion, Ashraf Farahat, Nayla El-Kork, Ramesh P. Singh, Feng Jing

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

On 4 August 2020, a strong explosion occurred near the Beirut seaport, Lebanon and killed more than 200 people and damaged numerous buildings in the vicinity. As Amonium Nitrate (AN) caused the explosion, many studies claimed the release of large amounts of NO₂ in the atmosphere may have resulted in a health hazard in Beirut and the vicinity. In order to reasonably evaluate the significance of NO₂ amounts released in the atmosphere, it is important to investigate the spatio-temporal distribution of NO₂ during and after the blast and compare it to the average day-to-day background emissions from …

An Intercomparison Of Large-Eddy Simulations Of A Convection Cloud Chamber Using Haze-Capable Bin And Lagrangian Cloud Microphysics Schemes, Fan Yang, Fabian Hoffmann, Raymond Shaw, Mikhail Ovchinnikov, Andrew Vogelmann

Michigan Tech Research Data

Recent in-situ observations show that haze particles exist in a convection cloud chamber. The microphysics schemes previously used for large-eddy simulations of the cloud chamber could not fully resolve haze particles and the associated processes, including their activation and deactivation. Specifically, cloud droplet activation is modeled based on Twomey-type parameterizations, wherein cloud droplets are formed when a critical supersaturation for the available cloud condensation nuclei (CCN) is exceeded and haze particles are not explicitly resolved. Here, we develop and adapt haze-capable bin and Lagrangian microphysics schemes to properly resolve the activation and deactivation processes. Results are compared with the Twomey-type …

Arctic Sea Ice Loss In The Pacific Sector And Its Impacts On Sudden Stratospheric Warming Events, Jiarong Zhang

Electronic Theses and Dissertations

The Arctic sea ice is a critical indicator of climate change. The extent of sea ice coverage over the Arctic Ocean has dramatically declined over the past few decades. The impact has been extensively studied through observations suggesting a linkage between the anomalously warm Arctic surface associated with the Arctic sea ice loss and the mid-latitude surface cooling in the subsequent boreal winter. This linkage could involve the wintertime stratospheric circulation by enhancing the upward planetary wave activity and weakening the polar vortex. With recent advances in climate model, more relevant studies relied on numerical simulations and some suggested that …

Improving Near Surface Refractivity Estimates In Marine Environments, Sarah Evelyn Wessinger

Electronic Theses and Dissertations

This study utilizes in-situ measurements and numerical weather prediction datasets collected during the Coupled Air-Sea Processes Electromagnetic Ducting Research East field campaign to assess how thermodynamic properties in the marine atmospheric surface layer influence evaporation duct shape and to develop a simple near-surface modified refractivity estimation method. This study utilizes a logarithmic linear parametric model, which describes evaporation ducts via three main parameters: evaporation duct height, evaporation duct curvature, and mixed layer slope. Notably, most studies utilizing this type of model assume the curvature, C0, to be a theoretical value derived assuming neutral atmospheric stability; a thermodynamic regime that is …

On A Guiding Of Whistler-Mode Waves By Density Gradients, Anatoly V. Streltsov

Publications

Observations from satellites demonstrate that in the magnetosphere, VLF whistler-mode waves are frequently detected in the narrow transition regions, where the plasma density changes its magnitude over a short distance across the ambient magnetic field. These observations suggest that the small-scale, isolated density gradients can guide the VLF whistler-mode waves along the field. We investigate the guiding of the whistler-mode waves by the transverse density gradients with a size much less than the characteristic perpendicular size of the wave. We found analytical solutions describing these waves in the plasma with a sharp density discontinuity between two homogeneous regions, and confirm …

A Statistical Analysis Of Sporadic-E Characteristics Associated With Gnss Radio Occultation Phase And Amplitude Scintillations, Daniel J. Emmons, Dong L. Wu, Nimalan Swarnalingam

Faculty Publications

Statistical GNSS-RO measurements of phase and amplitude scintillation are analyzed at the mid-latitudes in the local summer for a 100 km altitude. These conditions are known to contain frequent sporadic-E, and the S4-σ_ϕ trends provide insight into the statistical distributions of the sporadic-E parameters. Joint two-dimensional S4-σ_ϕ histograms are presented, showing roughly linear trends until the S4 saturates near 0.8. To interpret the measurements and understand the sporadic-E contributions, 10,000 simulations of RO signals perturbed by sporadic-E layers are performed using length, intensity, and vertical thickness distributions from previous studies, with the assumption that the sporadic-E layer acts …

Black And Brown Carbon Optical Characterization In The El Paso - Ciudad Juarez Airshed, Pamela I. Lara

Open Access Theses & Dissertations

Black (EBC) and Brown (BrC) Carbon are ubiquitous constituents of atmospheric particulate matter that affect peopleâ??s health, disrupt ecosystems, and modulate local and global climate. Tracking the local deposition and sources of these aerosol particles is essential to better understanding their multidimensional environmental impact. The main goal of the current study is to measure the absorption coefficient (Babs) of particles within the Planetary Boundary Layer (PBL) of the El Paso (US)–Ciudad Juárez (Mexico) airshed and assess the contribution of black and brown carbon particles to the total optical absorption. Measurements were taken during winter (January, 2022), spring (May, 2022), and …

The Simulated Sensitivity Of The North American Monsoon At Convection-Permitting Scales, Brendan Wallace

Legacy Theses & Dissertations (2009 - 2024)

The North American Monsoon (NAM) is a major contributor to annual rainfall for large portions of the North American Southwest. Much of the prior work examining the NAM using numerical models has been done at scales exceeding 20-km grid spacing. At these coarse scales, unresolved processes and poorly resolved geographic features can impact model performance. This can present a problem when simulating the NAM particularly with regard to orographic precipitation, precipitation on sub-daily timescales, and land surface-atmosphere interactions. This dissertation seeks to better understand the NAM through examination of several sets of convection-permitting regional climate model output. The primary goal …

Comparison Of 2018-2021 Tropical Cyclone Track Forecasts Before And After Noaa G-Iv Missions, Melissa Piper

Legacy Theses & Dissertations (2009 - 2024)

Tropical cyclone (TC) hazards are primarily dictated by the TC position; thus, it is important to produce accurate TC track forecasts. Many different features can influence a TC’s motion, yet these features are not always well sampled by in-situ observations over the open ocean, creating a need for supplemental observation collected via aircraft, including the deployment of dropsondes. In 1997, the National Hurricane Center (NHC) began operational synoptic surveillance missions in the near-storm environments of TCs using the Gulfstream IV-SP jet aircraft (G-IV), with the goal of reducing track forecast errors. In the first 10 years of operational missions, the …

Large-Scale Flow Patterns Conducive To Central American Extreme Precipitation Events During Autumn, Alexander Kyle Mitchell

Legacy Theses & Dissertations (2009 - 2024)

Extreme precipitation events (EPEs), characterized by daily widespread heavy rainfall exceeding the 95th percentile across Central America, can have large impacts on agriculture, life, and property during the rainy season. EPEs during the Northern Hemisphere (NH) autumn, however, have been observed to be influenced by both tropical and extratropical originating phenomena such as easterly waves and cold surges, respectively. Given the limited research in this area, the novelty of this work is to apply a systematic approach for identifying and better understanding EPEs, and investigating their associated synoptic-scale variability using daily high-resolution observations and reanalysis products over Central America. An …

A Composite Analysis Of Summer Afternoon Heavy Precipitation Events In The Taipei Basin Under Weak Synoptic Forcing And Pm2.5 Changes, Cidny Ramirez Martinez

Legacy Theses & Dissertations (2009 - 2024)

Taipei, Taiwan is a city affected by various types of precipitation. However, one of the most impactful short-term sources of precipitation is afternoon thunderstorms. Understanding the trends of these afternoon thunderstorms and the extent to which PM2.5 impacts precipitation totals is imperative for improving forecasting and developing urban infrastructure that can deal with said totals.

Probabilistic Forecasting Of Winter Mixed Precipitation Types In New York State Utilizing A Random Forest, Brian Chandler Filipiak

Legacy Theses & Dissertations (2009 - 2024)

Operational forecasters face a plethora of challenges when making a forecast; they must consider multiple data sources ranging from radar and satellites to surface and upper air observations, to numerical weather prediction output. Forecasts must be done in a limited window of time, which adds an additional layer of difficulty to the task. These challenges are exacerbated by winter mixed precipitation events where slight differences in thermodynamic profiles or changes in terrain create different precipitation types across small areas. In addition to being difficult to forecast, mixed precipitation events can have large-scale impacts on our society.

¿Aviso O Alerta? Developing Effective, Inclusive, And Consistent Watch And Warning Translations For U.S. Spanish Speakers, Joseph E. Trujillo-Falcón, América R. Gaviria Pabón, Joseph T. Ripberger, Abby Bitterman, Jonathan B. Thornton, Mackenzie J. Krocak, Sean R. Ernst, Estilita Cassiani Obeso, John Lipski

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

Spanish-speaking populations in the United States are more vulnerable in disaster contexts due to inequities, such as language barriers, that prevent them from receiving life-saving information. For the past couple of decades, governmental organizations have addressed these issues by translating weather watches, warnings, and advisories into Spanish. Previous studies suggest that these Spanish translations do not communicate the same level of urgency as their English counterparts. To identify whether these translated products result in inequities between English and Spanish speaker reception and comprehension of forecast information, we asked a representative sample of U.S. English (n = 1,550) and Spanish (n …

Identifying Particulate Matter Spatial Variation In The El Paso Del Norte Region Using Land-Use Regression Modeling And Data Obtained From A Network Of Low-Cost Sensors, Leonardo Demetrio Vazquez-Raygoza

Open Access Theses & Dissertations

The emergence and rise in popularity of low-cost sensors for atmospheric observation aresetting a new precedent in identifying emission hotspots and providing high-resolution spatial and temporal data. Furthermore, low-cost sensors are becoming popular among institutions and the public, allowing community scientists to become more involved in air quality monitoring. However, concerns about the accuracy and precision of low-cost sensors have been questioned. Most recent research has focused on the utility of real-time monitoring and calibration requirements for these sensors. A low-cost monitoring project has deployed sensors in the El Paso del Norte region in low and high annual average daily …

Wavenumbers 3 And 4 Quasi 2-Day Wave Activities Observed By Multiple Meteor Radars In The Two Hemispheres During Austral Summer, Hao Cheng, Kai Ming Huang, Alan Z. Liu, Shao Dong Zhang, Chun Ming Huang, Yun Gong

Publications

Combining observations from three meteor radars in the Northern Hemisphere (NH) and a meteor radar in the Southern Hemisphere (SH) and reanalysis data, we present successive wavenumbers 3 and 4 (W3 and W4) quasi 2 day wave activities in austral summer. In the mesosphere and lower thermosphere, the wave exhibits two burst activities. The W3 dominates the first burst, while the W4 is the predominate mode in the second burst. The mode transition arises in the late January and is completed around the end of January. The W3 and W4 have the nearly same dominate period of about 46 hr …

Increased Aerosols Can Reverse Twomey Effect In Water Clouds Through Radiative Pathway, Pradeep Khatri, Tadahiro Hayasaka, Brent N. Holben, Ramesh P. Singh, Husi Letu, Sachchida N. Tripathi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aerosols play important roles in modulations of cloud properties and hydrological cycle by decreasing the size of cloud droplets with the increase of aerosols under the condition of fixed liquid water path, which is known as the first aerosol indirect effect or Twomey-effect or microphysical effect. Using high-quality aerosol data from surface observations and statistically decoupling the influence of meteorological factors, we show that highly loaded aerosols can counter this microphysical effect through the radiative effect to result both the decrease and increase of cloud droplet size depending on liquid water path in water clouds. The radiative effect due to …

Coupling Evidence From Lower Atmosphere To Mesosphere And Ionosphere Through Quasi 27-Day Oscillation, Alan Z. Liu, Kaiming Huang, Hao Cheng, Shaodong Zhang, Chunming Huang, Yun Gong, Gang Chen

Publications

Using meteor radar, radiosonde and digisonde observations and MERRA-2 reanalysis data from 12 August to 31 October 2006, we report a dynamical coupling from the tropical lower atmosphere to the mesosphere and ionospheric F2 region through a quasi 27-day intraseasonal oscillation (ISO). It is interesting that the quasi 27-day ISO is active in the troposphere and stratopause and mesopause regions, exhibiting a three-layer structure. In the mesosphere and lower thermosphere (MLT), the amplitude in the zonal wind increases from about 4 ms at 90 km to 15 ms at 100 km, which is different from previous observations that ISOs generally …

The Dynamics Of Tsunamigenic Acoustic-Gravity Waves And Bathymetry Effect, Pavel Alexandrovich Inchin, Christopher James Heale, Jonathan Brian Snively, Matthew David Zettergren

Publications

The investigation of atmospheric tsunamigenic acoustic and gravity wave (TAGW) dynamics, from the ocean surface to the thermosphere, is performed through the numerical computations of the 3D compressible nonlinear Navier-Stokes equations. Tsunami propagation is first simulated using a nonlinear shallow water model, which incorporates instantaneous or temporal evolutions of initial tsunami distributions (ITD). Surface dynamics are then imposed as a boundary condition to excite TAGWs into the atmosphere from the ground level. We perform a case study of a large tsunami associated with the 2011 M9.1 Tohuku-Oki earthquake, and parametric studies with simplified and demonstrative bathymetry and ITD. Our results …

Climatology Of High-Frequency Gravity Waves Observed By An Airglow Imager At Andes Lidar Observatory, Alan Z. Liu, Bing Cao

Publications

The long-term climatology of high-frequency quasi-monochromatic gravity waves is presented using multi-year airglow images observed at Andes Lidar Observatory (ALO, 30.3ºS, 70.7ºW) in northern Chile. A large number of high-frequency gravity waves were retrieved from OH airglow images. The distribution of primary wave parameters including horizontal wavelength, vertical wavelength, intrinsic wave speed, and intrinsic wave period are obtained and are in the ranges of 20–30 km, 15–25 km, 50–100 ms-1, and 5–10 min, respectively. The waves tend to propagate against the local background winds and show clear seasonal variations. In austral winter (Ma–Aug), the observed wave occurrence frequency is higher …

Estimation Of Economic Risk From Coastal Natural Hazards In Louisiana, Rubayet Bin Mostafiz

LSU Doctoral Dissertations

Louisiana, U.S.A., is among the most vulnerable areas globally to coastal natural hazards, with risk vulnerability likely increasing. The risks associated with non-tropical-cyclone hazards in Louisiana’s coastal zone have been understudied. This research enhances present and future (i.e., 2050) Louisiana risk assessment using locally-weighted, model-based hazard frequency/intensity and population projections.

Results suggest that property risks associated with extreme cold temperature and tornado are and will remain costlier than those for hail and lightning. Property risks of extreme cold temperature and hail are projected to decrease with the expected warming temperatures, with those of all four of these hazards peaking in …