Atmospheric Sciences Commons^™

Feasibility Analysis Of Aeronet Lunar Aod For Nighttime Particulate Matter Estimation, Kwang Nyun Kim, Seung Hee Kim, Sang Seo Park, Yun Gon Lee

Institute for ECHO Articles and Research

Several studies have attempted to estimate particulate matter (PM) concentrations using aerosol optical depth (AOD), based on AOD and PM relationships. Owing to the limited availability of nighttime AOD data, PM estimation studies using AOD have focused on daytime. Recently, the Aerosol Robotic Network (AERONET) produced nighttime AOD, called lunar AOD, providing an opportunity to estimate nighttime PM. Nighttime AOD measurements are particularly important as they help fill gaps in our understanding of aerosol variability and its impact on the atmosphere, as there are significant variations in AOD between day and night. In this study, the relationship between lunar AOD …

Verification Of The Localized Aviation Mos Program (Lamp) At Major Us Airports For Ifr Conditions, Mackenzie O'Rourke

Theses and Dissertations

The objective of this research is to quantify the LAMP’s performance when forecasting for IFR conditions at specific major airports for forecast hours one, three, six, and twelve, and further determine how the LAMP performs seasonally at those specific airports and forecast hours. Two by two contingency tables were used to calculate the Probability of Detection (POD), False Alarm Ratio (FAR), Critical Success Index (CSI), Heidke Skill Score (HSS), and Bias score. The results show that the LAMP performs relatively better in the cool season compared to the warm season consistently at each chosen airport, and that the LAMP performs …

Atmospheric Impacts From The 2010 Deepwater Horizon Oil Spill, Charles Philip Johnson

LSU Master's Theses

Although the ecological devastations induced by an oil spill are well studied, the hydrometeorological impacts from a long-term slick have gone unnoticed. The ocean-surface alterations stemming from the lasting oil footprint increase solar radiation absorption which in turn alters the surface pressure and moisture gradients and wind speeds thereby influencing precipitation surrounding the oil spill. Revealing the potential impacts from these could better aid in the safety of crews cleaning spills and provide a better understanding of how humans alter the landscape. This thesis examines the changes in local hydrometeorology brought on by the 2010 summer Deepwater Horizon (DWH) oil …

Radar Signatures In Tropical Cyclone Tornadic And Nontornadic Supercells, Michaela Wood

Dissertations & Theses in Earth and Atmospheric Sciences

Tropical cyclones (TCs) contain highly-sheared environments that are conducive for supercell thunderstorms. These TC supercells sometimes produce tornadoes, often with little warning. Given the often-close proximity of tornadic and nontornadic TC supercells, environments may not be well-distinguished, pointing to the potential value of radar observations. In this study, dual-polarimetric radar signatures of a sample of TC supercells are examined in the context of known supercell structure and microphysics. Tornadic and nontornadic TC supercells are compared with their midlatitude counterparts, and the environments and characteristic structure of these storms are shown to be notably different. An attempt is made to distinguish …

Studies Of The Ionosphere-Thermosphere Responses To Multi-Scale Energy Deposition Processes, Haonan Wu

All Dissertations

The Ionosphere-Thermosphere (I-T) system is greatly affected by the magnetospheric energy deposition from above and subjected to forcing from the lower atmosphere simultaneously. A central problem in studying the coupled I-T system is to analyze the multi-scale processes naturally embedded in both ways. Magnetospheric energy input such as auroral precipitation and electric field demonstrates multi-scale structures during magnetic storms, resulting in multi-scale I-T responses when deposited into the I-T system. To better quantify the multi-scale aurora and electric field, we developed a new data assimilation model based on a multi-resolution Gaussian process model to synthesize empirical models and observational data …

Cloud Microphysical Response To Entrainment And Mixing Is Locally Inhomogeneous And Globally Homogeneous: Evidence From The Lab, Jaemin Yeom, Ian Helman, Prasanth Prabhakaran, Jesse Anderson, Fan Yang, Raymond Shaw, Will Cantrell

Michigan Tech Research Data

The effects of entrainment-mixing on the cloud droplet size distribution are examined in the Pi cloud chamber that creates a turbulent supersaturated environment for cloud formation. The experiments are conducted with a temperature-controlled flange to mimic the entrainment-mixing process. The entrainment zone is created at the center of the top surface of the chamber, allowing dry air of controlled temperature (T_e) and flow rate (Q_e) to flow into the mixing cloud region. Due to the large-scale circulation, the downwind region is directly affected by entrained dry air from the flange, whereas the upwind region is representative …

Accelerating Atmospheric Gravity Wave Simulations Using Machine Learning: Kelvin-Helmholtz Instability And Mountain Wave Sources Driving Gravity Wave Breaking And Secondary Gravity Wave Generation, Wenjun Dong, David Fritts, Alan Z. Liu, Hanli Liu, Jonathan Snively

Publications

Gravity waves (GWs) and their associated multi-scale dynamics are known to play fundamental roles in energy and momentum transport and deposition processes throughout the atmosphere. We describe an initial, two-dimensional (2-D), machine learning model – the Compressible Atmosphere Model Network (CAMNet) - intended as a first step toward a more general, three-dimensional, highly-efficient, model for applications to nonlinear GW dynamics description. CAMNet employs a physics-informed neural operator to dramatically accelerate GW and secondary GW (SGW) simulations applied to two GW sources to date. CAMNet is trained on high-resolution simulations by the state-of-the-art model Complex Geometry Compressible Atmosphere Model (CGCAM). Two …

Dynamic Characteristics Of Aerosol Optical Properties Over Dibrugarh City In The North-Eastern Indian Region During 2018–2021, Akshansa Chauhan, Shukla Acharjee, Ramesh P. Singh, Brent N. Holben

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aerosols play an important role in the earth's environment across the globe through their involvement in various earth system cycles. The change in the aerosol properties may cause short and long-term impacts, the knowledge of such changes is useful in the estimation of the pollution sources of any region. We have carried out the analysis of the aerosols' optical and radiative properties using AERONET station data from 2018 to 2021 in Dibrugarh City. The higher Aerosol Optical Depth (AOD) values during winter and pre-monsoon months indicate high anthropogenic activities, and biomass burning in Dibrugarh. The impact of various sources and …

Communicating About Extreme Heat: Results From Card Sorting And Think Aloud Interviews With Experts From Differing Domains, Jeannette Sutton, Nicholas Waugh, Savannah Olivas

Emergency Preparedness, Homeland Security, and Cybersecurity Faculty Scholarship

Climate trends indicate that extreme heat events are becoming more common and more severe over time, requiring improved strategies to communicate heat risk and protective actions. However, there exists a disconnect in heat-related communication from experts, who commonly include heat related jargon (i.e., technical language), to decision makers and the general public. The use of jargon has been shown to reduce meaningful engagement with and understanding of messages written by experts. Translating technical language into comprehensible messages that encourage decision makers to take action has been identified as a priority to enable impact-based decision support. Knowing what concepts and terms …

Molecular Dynamics Simulation Data: Mw And Mlmw Water Model Ice Nucleation On A Hydrophilic Substrate With Negative Pressure, Will Cantrell, Tianshu Li, Issei Nakamura, Elise Rosky, Raymond Shaw

Michigan Tech Research Data

This dataset contains the data supporting Figures in the study by Rosky et al., "Molecular simulations reveal that heterogeneous ice nucleation occurs at higher temperatures in water under capillary tension", submitted for publication in Atmospheric Chemistry and Physics in February 2023. Input files for reproducing the molecular dynamics simulations are included.

The abstract from the paper reads: Using a molecular model of water freezing on a hydrophilic substrate, it is found that heterogeneous ice nucleation rates occur at higher temperatures in water that is under tension, in other words under negative pressure. For pressures ranging from from 1 atm to …

Gravity Wave Drag Parameterizations For Earth’S Atmosphere, Christopher J. Heale, Christopher G. Kruse, Jadwiga H. Richter, M. Joan Alexander, Julio T. Bacmeister, Junhong Wei

Publications

Atmospheric gravity waves (GWs), or buoyancy waves, transport momentum and energy through Earth’s atmosphere. GWs are important at nearly all levels of the atmosphere, though, the momentum they transport is particularly important in general circulation of the middle and upper atmosphere. Primary sources of atmospheric GWs are flow over mountains, moist convection, and imbalances in jet/frontal systems. Secondary GWs can also be generated as a result of dissipation of a primary GWs. Gravity waves typically have horizontal wavelengths of 10’s to 100’s of kilometers, though, they can have scales of 1’s to 1000’s of kilometers as well. Current effective resolutions …

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 …

The Behavior Of Partially Coherent Twisted Space-Time Beams In Atmospheric Turbulence, Milo W. Hyde Iv

Faculty Publications

We study how atmospheric turbulence affects twisted space-time beams, which are non-stationary random optical fields whose space and time dimensions are coupled with a stochastic twist. Applying the extended Huygens–Fresnel principle, we derive the mutual coherence function of a twisted space-time beam after propagating a distance z through atmospheric turbulence of arbitrary strength. We specialize the result to derive the ensemble-averaged irradiance and discuss how turbulence affects the beam’s spatial size, pulse width, and space-time twist. Lastly, we generate, in simulation, twisted space-time beam field realizations and propagate them through atmospheric phase screens to validate our analysis.

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 …

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 …

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 …

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 …

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 …