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Articles 121 - 150 of 2453

Full-Text Articles in Atmospheric Sciences

Vertical Gradient In Atmospheric Particle Phase State: A Case Study Over The Alaskan Arctic Oil Fields, Nurun Nahar Lata, Zezhen Cheng, Darielle Dexheimer, Susan Mathai, Matthew A. Marcus, Kerri A. Pratt Feb 2025

Vertical Gradient In Atmospheric Particle Phase State: A Case Study Over The Alaskan Arctic Oil Fields, Nurun Nahar Lata, Zezhen Cheng, Darielle Dexheimer, Susan Mathai, Matthew A. Marcus, Kerri A. Pratt

Michigan Tech Publications

The phase state of atmospheric particles impacts atmospheric processes like heterogeneous reactions, cloud droplet activation, and ice nucleation, influencing Earth's climate. Factors like chemical composition, temperature, and relative humidity govern particle phase states. The Arctic atmosphere is stratified, with varying particle compositions, but vertical profiles of submicron phase states remain poorly understood due to limited aloft measurements. To address this, particle samples were collected via a tethered balloon system (TBS) at the U.S. Department of Energy Atmospheric Radiation Measurement Program's facility at Oliktok Point, Alaska, on November 19, 2020. Using an environmental scanning electron microscope with a tilted Peltier stage …


2024 Nhc Verification Report Preview: Atlantic Basin, John Cangialosi, Jon Martinez Feb 2025

2024 Nhc Verification Report Preview: Atlantic Basin, John Cangialosi, Jon Martinez

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

The National Hurricane Center (NHC) is nearing completion of the post-analysis of the 2024 Atlantic and eastern North Pacific basin tropical cyclones. The annual NHC Verification Report uses the post-analyzed information to verify the accuracy and biases of NHC forecasts and real-time model guidance, and the 2024 report will be available in the spring on NHC’s website - https://www.nhc.noaa.gov/verification/. This short review provides some of the preliminary highlights of NHC’s 2024 forecast performance in the Atlantic basin, which is based on a combination of post-analyzed and real time best track data. If interested in the forecast verification for individual …


Coupled Lake-Atmosphere-Land Physics Uncertainties In A Great Lakes Regional Climate Model, William J. Pringle, Chenfu Huang, Pengfei Xue, Jiali Wang, Khachik Sargsyan, Miraj Kayastha, Et. Al. Feb 2025

Coupled Lake-Atmosphere-Land Physics Uncertainties In A Great Lakes Regional Climate Model, William J. Pringle, Chenfu Huang, Pengfei Xue, Jiali Wang, Khachik Sargsyan, Miraj Kayastha, Et. Al.

Michigan Tech Publications

This study develops a surrogate-based method to assess the uncertainty within a convective permitting integrated modeling system of the Great Lakes region, arising from interacting physics parameterizations across the lake, atmosphere, and land surface. Perturbed physics ensembles of the model during the 2018 summer are used to train a neural network surrogate model to predict lake surface temperature (LST) and near-surface air temperature (T2m). Average physics uncertainties are determined to be 1.5°C for LST and T2m over land, and 1.9°C for T2m over lake, but these have significant spatiotemporal variations. We find that atmospheric physics parameterizations alone are the dominant …


Increasing Atmospheric Evaporative Demand Across The Tibetan Plateau And Implications For Surface Water Resources, Shiqin Xu, Dennis P. Lettenmaier, Tom R. Mcvicar, Pierre Gentine, Hylke E. Beck, Joshua B. Fisher, Zhongbo Yu, Ningpeng Dong, Akash Koppa, Matthew F. Mccabe Jan 2025

Increasing Atmospheric Evaporative Demand Across The Tibetan Plateau And Implications For Surface Water Resources, Shiqin Xu, Dennis P. Lettenmaier, Tom R. Mcvicar, Pierre Gentine, Hylke E. Beck, Joshua B. Fisher, Zhongbo Yu, Ningpeng Dong, Akash Koppa, Matthew F. Mccabe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The Tibetan Plateau, known as the “Asian water tower,” is a hotspot for complex hydroclimatic changes. We reveal that the previously decreasing atmospheric evaporative demand (Eo) trend at the end of the 20th century has reversed over the last two decades. Although both wind stilling and solar dimming have persisted, their effects on Eo rates have been overshadowed by increasing air temperatures and decreasing relative humidity, leading to a net rise in Eo for 1980−2015. Using the empirical “top-down” Budyko approach, we estimate that across seven sub-catchments draining the Tibetan Plateau, a 10% increase in annual-averaged …


The Unique Features Of Typhoon Rai (2021): An Observational Study, Clint Eldrick R. Petilla, Lyndon Mark P. Olaguera, Faye Abigail T. Cruz, Jose Ramon T. Villarin, Hironori Fudeyasu, Ryuji Yoshida, Jun Matsumoto Jan 2025

The Unique Features Of Typhoon Rai (2021): An Observational Study, Clint Eldrick R. Petilla, Lyndon Mark P. Olaguera, Faye Abigail T. Cruz, Jose Ramon T. Villarin, Hironori Fudeyasu, Ryuji Yoshida, Jun Matsumoto

Physics Faculty Publications

Tropical Cyclone (TC) RAI (2021) made a devastating landfall in the Siargao-Dinagat Islands of the southeastern Philippines on December 16, 2021, causing about USD 942 M in damage, 405 reported deaths and 52 missing. Yet, observational studies on the environmental conditions during TC RAI remain limited, and a comparison with other landfalling TCs were not done. To shed light on the factors that made this TC reach a maximum sustained wind speed (MSW) of 105 kts (194.5 kph) and 915 hPa mean sea level pressure according to the WMO-IBTrACS, this study investigated the meteorological statistics of this TC relative to …


Rain-On-Snow Event Climatology And Hydrological Impacts In The Connecticut River Watershed, Samuel Davidson Jan 2025

Rain-On-Snow Event Climatology And Hydrological Impacts In The Connecticut River Watershed, Samuel Davidson

Masters Theses & Specialist Projects

Rain-on-snow events, characterized by rain falling on existing snowpack, have the potential to bring about significant hydrological and environmental impacts including snowmelt, flooding, landslides, and other natural hazards. Despite prior evidence suggesting the Connecticut River Watershed has endured socioeconomic and environmental setbacks due to rain-on-snow events in the past, limited prior research has been performed on the role of rain-onsnow events within the region’s hydroclimatology. Gaining a deeper understanding of the occurrence and impacts of such events would provide valuable insights for risk and water resource managers. The purpose of this research was to create a climatology of rain-on-snow events …


Statistical Analysis Of Climate Trends And Variability In Tarrant County Using Annual, Decade, And Three-Decade Time Periods, Quinnton Debolt Jan 2025

Statistical Analysis Of Climate Trends And Variability In Tarrant County Using Annual, Decade, And Three-Decade Time Periods, Quinnton Debolt

Earth & Environmental Sciences Theses - Archive

This study is a statistical analysis of climate trends within the Dallas-Fort Worth metroplex according to several time-scale models to understand how the climate for the locality has changed and to provide a basis for projections of what future climate might look like. Trends in mean temperature and precipitation for North Central Texas generally correlate with corresponding global trends linked to natural variability and anthropogenic-induced climate change. Temperature rises in this region annually by 0.08°C and by 0.22°C for a three-decade average. Seasonal increases in three-decadal averages of temperature for North Central Texas relative to the average of the reference …


Stratospheric Variability And Its Relationship To Cold Air Outbreaks In The United States, Paul T. Panhans Jan 2025

Stratospheric Variability And Its Relationship To Cold Air Outbreaks In The United States, Paul T. Panhans

Electronic Theses & Dissertations (2024 - present)

Only since the early 2000s, has there been a growing body of work linking extreme winter temperature anomalies to the variability of the Northern Hemisphere stratospheric polar vortex (SPV). However, the understanding behind stratosphere-troposphere coupling and cold air outbreaks (CAOs) remain occasionally contradictory in the literature, making it difficult to properly articulate societal risks. Studies often focused on broad stratospheric influences, but this research directly compared stratospheric variability according to their respective tropospheric impacts. This dissertation filled a knowledge gap, as there has yet to be a comprehensive analysis to quantify the differences in stratospheric variability with and without CAOs …


Influence Of Cloud-Radiative Forcing On Tropical Cyclone Development In Moderate Vertical Wind Shear, Jannetta C. Richardson Jan 2025

Influence Of Cloud-Radiative Forcing On Tropical Cyclone Development In Moderate Vertical Wind Shear, Jannetta C. Richardson

Electronic Theses & Dissertations (2024 - present)

This research seeks to better understand how cloud–radiative forcing (CRF) influences the structural evolution and intensity change of tropical cyclones (TCs) during the organizaional stage, with a particular focus on environments characterized by moderate vertical wind shear. While CRF has been shown to impact TC development during genesis and mature stages, its role during the transitional post-genesis phase—when TCs exhibit disorganized convection and are highly sensitive to environmental influences—remains poorly understood. Moreover, forecasting TC intensity in moderate shear environments continues to present substantial challenges, underscoring the need for focused investigation of TC development in the moderate-shear regime.

The Weather Research …


Dynamics Of Mesoscale Offshore Wind Flows From An Observational And Modeling Perspective: Implications For Offshore Wind Energy, Elizabeth J. Mccabe Jan 2025

Dynamics Of Mesoscale Offshore Wind Flows From An Observational And Modeling Perspective: Implications For Offshore Wind Energy, Elizabeth J. Mccabe

Electronic Theses & Dissertations (2024 - present)

Mid-latitude coastal regions of the United States, such as the New York Bight (NYB), are playing a major role in the development of offshore wind energy. However, mesoscale dynamics of local and regional circulations in these offshore waters are poorly understood. The sea breeze, especially in the NYB, will play a key role in the development of offshore wind energy, given the favorable wind speeds and high capacity factors during periods of peak demand. With limited vertical wind profile observations available offshore, the ability to accurately forecast and understand the spatiotemporal extent of the sea breeze and often associated low-level …


Verification Of Real-Time Smoke Simulations: A Case Study On Early Summer North American Wildfire Events, Daniel Bonilla Jan 2025

Verification Of Real-Time Smoke Simulations: A Case Study On Early Summer North American Wildfire Events, Daniel Bonilla

Pitzer Senior Theses

As wildfire intensity and frequency escalate in times of unprecedented climate change and severe droughts, it is important to enhance forecasting models that accurately and efficiently predict wildfire smoke movement. NOAA’s experimental Rapid-Refresh Forecasting System with Smoke and Dust (RRFS-SD) aims to improve upon the High-Resolution Rapid Refresh- Smoke (HRRR-Smoke), by extending the domain to include all of North America and incorporating new developments in physics and wildfire parameterizations. Our work explores the process of adding satellite Aerosol Optical Depth (AOD) data, through AERONET, as an additional method of verification of the RRFS-SD experimental model. Using a case study on …


Collision-Induced Absorption Spectra Of N₂ And Ch₄, Ryan M. Johnson, Peter F. Bernath, Brant Billinghurst, Jianbao Zhao Jan 2025

Collision-Induced Absorption Spectra Of N₂ And Ch₄, Ryan M. Johnson, Peter F. Bernath, Brant Billinghurst, Jianbao Zhao

Chemistry & Biochemistry Faculty Publications

Collision-induced spectra are essential for radiative transfer modeling of Titan's atmosphere. We present experimental spectra of nitrogen–methane mixtures with an accompanying fit of N₂-CH₄ collision-induced absorption in the 30–400 cm⁻¹ region at about 130 K. We found a peak absorption of 2.30 × 10⁻⁵ cm⁻¹ amagat⁻² at 75 cm⁻¹ and a secondary peak of 1.35 × 10⁻⁵ c⁻¹ amagat⁻² at 206.5 cm⁻¹, which agrees with previous studies. Our work does not support the suggestion that N₂-CH₄ CIA in the far-infrared should be increased by about 50%, as suggested by spectroscopic modeling of Titan using data from A. Borysow & C. …


High-Altitude Balloon-Launched Uncrewed Aircraft System Measurements Of Atmospheric Turbulence And Qualitative Comparison With Infrasound Microphone Response, Anisa Haghighi Jan 2025

High-Altitude Balloon-Launched Uncrewed Aircraft System Measurements Of Atmospheric Turbulence And Qualitative Comparison With Infrasound Microphone Response, Anisa Haghighi

Theses and Dissertations--Mechanical and Aerospace Engineering

This study explores the use of a balloon-launched uncrewed aircraft system (UAS) to measure atmospheric turbulence in the troposphere and lower stratosphere using both wind velocity measurements and infrasonic acoustic energy. The UAS, a glider configured for autonomous descent along a predefined trajectory, had on board, in situ sensors to capture thermodynamic and kinematic atmospheric parameters. Additionally, it carried an infrasonic microphone to evaluate its potential for remotely detecting clear-air turbulence by capturing infrasonic waves. The system’s performance was assessed over the course of three test flights conducted in New Mexico, USA, in 2021. The descent enabled high-resolution profiling, with …


A Wall Of Smoke: Understanding The Drivers Of The June 2023 Canadian Wildfire Smoke Event For New York City, Gregory S. Randazzo Jan 2025

A Wall Of Smoke: Understanding The Drivers Of The June 2023 Canadian Wildfire Smoke Event For New York City, Gregory S. Randazzo

Dissertations and Theses

The 2023 Canadian wildfire season was notable for its extent and the dense smoke it produced. Motivated by the resulting air quality impacts in the New York City region, we explore how the total particulate matter output from the Quebec fires influenced PM2.5 concentrations downstream in New York City. Using injection height data from the Regional Advanced Baseline Imager + VIIRS Emissions dataset, we relate the tropospheric injection heights of the fires with the broader synoptic context and surface PM2.5 concentrations. Using data from the NYS Mesonet Profiler Network, radiosondes, and ERA5 reanalysis, we document the connection between an anomalous …


Development Of An Quadcopter Unmanned Aerial Vehicle For Atmospheric Remote Sensing, Omar J. Addasi Jan 2025

Development Of An Quadcopter Unmanned Aerial Vehicle For Atmospheric Remote Sensing, Omar J. Addasi

Dissertations and Theses

This paper explores the development of a quadcopter unmanned aerial vehicle (UAV, a.k.a. drone) for atmospheric remote sensing of temperature, pressure, humidity, and PM2.5 particulate matter quantities. A 3-D printed drone body is designed and flight tuning is performed. An optimal length for an upward extending mast for the drone body is determined. Low cost, lightweight sensors are compared against higher precision sensors in both static and dynamic conditions. In addition, an initial investigation into the design of a pressure sensor based anemometer is performed.


Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones Jan 2025

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …


Atmospheric Chemistry Experiment (Ace) Winds, Matthew Wyatt, Peter F. Bernath, Chris Boone, Léo Lavy, Ryan Johnson Jan 2025

Atmospheric Chemistry Experiment (Ace) Winds, Matthew Wyatt, Peter F. Bernath, Chris Boone, Léo Lavy, Ryan Johnson

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) uses limb geometry to measure transmittance spectra of Earth's atmosphere by solar occultation. Line-of-sight wind speeds can be derived via Doppler shifts of molecular lines in infrared spectra. The wind look direction angles relative to geodetic North are derived from geometry. We validate the new ACE version 5.3 (v.5.3) line-of-sight winds with MIGHTI and meteor radar vector wind observations and find a ±15 m/s sunrise/sunset shift above 80 km. We also compare line-of-sight winds from ACE-FTS v.5.2 and v.5.3 with vector winds from the MERRA-2, HWM14, and WACCM-X models. A ±15 m/s …


Co₂ Isotopologues From The Ace Satellite, D. English, P. Bernath, C. Boone Jan 2025

Co₂ Isotopologues From The Ace Satellite, D. English, P. Bernath, C. Boone

Chemistry & Biochemistry Faculty Publications

Carbon dioxide isotopologues have been studied thoroughly in the troposphere. In the stratosphere, the minor oxygen CO₂ isotopologues have anomalous abundances due to their exchange reactions with isotopically fractionated ozone, differentiating them from tropospheric CO₂. Previously a model predicted that this anomalous isotopic abundance continues into the mesosphere but lacked verification from experimental observations. Here we use the Atmospheric Chemistry Experiment Fourier Transform Spectrometer which records infrared transmittance spectra of the Earth's limb from low Earth orbit using solar occultation. These infrared spectra provide measurements of global CO₂ isotopologue volume mixing ratios (VMRs) from the upper troposphere to the lower …


Analysis Of Aerosols In The Asian Monsoon Anticyclone As Observed By The Atmospheric Chemistry Experiment, M. Lecours, R. Dodangodage, C. D. Boone, P. F. Bernath Jan 2025

Analysis Of Aerosols In The Asian Monsoon Anticyclone As Observed By The Atmospheric Chemistry Experiment, M. Lecours, R. Dodangodage, C. D. Boone, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

During the Asian summer monsoon season, pollutants from the lower troposphere are transported through deep convection to the upper troposphere and lower stratosphere. Surface pollutants such as CO are transported upward and trapped in the anticyclone during this unique atmospheric phenomenon. Associated with the anticyclone is a layer of enhanced aerosols located near the tropopause often referred to as the Asian tropopause aerosol layer (ATAL). The chemical and physical properties of aerosols in the ATAL are not yet fully understood as direct observations of the aerosols are limited. The Atmospheric Chemistry Experiment (ACE) is a satellite mission that provides high-resolution …


Twenty Years Of Global Stratospheric Fluorine Inventories From Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Measurements, N. Raymond, P. Bernath, C. Boone, M. Chipperfield Jan 2025

Twenty Years Of Global Stratospheric Fluorine Inventories From Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Measurements, N. Raymond, P. Bernath, C. Boone, M. Chipperfield

Chemistry & Biochemistry Faculty Publications

We present fluorine inventories calculated for twenty years (2004–2023) and five latitude bands (82°–60°N, 60°–30°N, 30°N–30°S, 30°–60°S, and 60°–82°S) at altitudes from the surface up to 55 km. The inventories were calculated using the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE‐FTS) version 5.2 retrievals of the volume mixing ratios (VMRs) of 15 fluorine‐containing species. Of these 15 species, 3 are product gases: HF, COF₂, COCIF, and 12 are source gases: SF₆, PFC-14 (CF₄), CFC-11 (CCl₃F), CFC-12 (CCl₂F₂), CFC-113 (CCIF₂CCl₂F), HCFC-22 (CHF₂CL), HCFC-141b(C₂H₃Cl₂F), HCFC-142b ( …


Characterizing The Earth's Magnetosheath With In Situ Measurements, Hector A. Salinas Jan 2025

Characterizing The Earth's Magnetosheath With In Situ Measurements, Hector A. Salinas

Physics Dissertations - Archive

Earth’s magnetosheath is a region of shocked plasma that mediates energy and momentum transfer from the solar wind to the magnetosphere. The dynamics and thus the plasma structures of this region are highly dependent on upstream solar wind conditions. As such, the region is often characterized as a turbulent environment, with the most intense periods of turbulence occurring often under quasi-parallel bow shock conditions. This magnetosheath turbulence displays as variable and large-scale fluctuations with in-situ measurements. Given that turbulence is a characteristic feature of the magnetosheath, this dissertation asks two questions: (1) How are plasma structures inside the sheath affected …


Using Convolutional Neural Networks To Identify Rare Weather Events: Application To Kona Low Classifications With Large-Scale Wind Pattern, Anadhi Sharma Jan 2025

Using Convolutional Neural Networks To Identify Rare Weather Events: Application To Kona Low Classifications With Large-Scale Wind Pattern, Anadhi Sharma

Electronic Theses & Dissertations (2024 - present)

Extreme events pose challenges in prediction on account of their low frequency and erratic nature. Among these events, Kona lows are rare subtropical cyclones that significantly impact the weather pattern of Hawaii, sometimes causing heavy rainfall, strong winds, and coastal flooding. In the past, studies have used traditional statistical methods such as synoptic climatology, regression analysis, and manual classification that rely on expert judgment to identify Kona lows; however, they often struggle to capture the complex spatial patterns of the Kona storms. Convolutional Neural Networks (CNNs) exhibit a property called translation invariance, which allows them to learn and recognize Kona …


Limitations Of The High-Resolution Rapid Refresh Gust Algorithm, Alex M. Glasser Jan 2025

Limitations Of The High-Resolution Rapid Refresh Gust Algorithm, Alex M. Glasser

Electronic Theses & Dissertations (2024 - present)

ABSTRACT:

Accurate wind and gust forecasts are crucial in operational meteorology, yet there is a distinct gap in the literature regarding the verification of operational gust forecasts. In the present work, we assess the performance of the High-Resolution Rapid Refresh's (HRRR) gust potential, verifying it against the Automated Surface Observing System's (ASOS) observed gusts across the Continental United States (CONUS). The HRRR gust's diurnal cycle reveals a significant underprediction of the gust during daylight hours and a slight overprediction of the gust during hours of darkness. The daytime underprediction undermines the assumption that forecasts represent a potential that tends to …


Using The High Resolution Rapid Refresh To Validate A Novel Forecast Methodology, Sylvia M. Garmong Jan 2025

Using The High Resolution Rapid Refresh To Validate A Novel Forecast Methodology, Sylvia M. Garmong

Electronic Theses & Dissertations (2024 - present)

NOAA’s High-Resolution Rapid Refresh (HRRR) is frequently used by forecasters for short term predictions and although the model performs well in many metrics, previous study (Fovell and Gallagher 2020) identified temperature and windspeed biases within the boundary layer using radiosonde and surface observations. The current work uses a forecast drift metric to study how model forecasts evolve with time and distance to radiosonde sites. The metric is calculated by subtracting model analysis from forecasts at the same valid time, creating a proxy for bias. HRRR data on native model levels are obtained from the Google Cloud and Amazon Web Services …


Misoscale Vortices In The Eyewall Boundary Layer Of A Tropical Cyclone In A Large Eddy Simulation, Emily A. Lucy Jan 2025

Misoscale Vortices In The Eyewall Boundary Layer Of A Tropical Cyclone In A Large Eddy Simulation, Emily A. Lucy

Electronic Theses & Dissertations (2024 - present)

Since the late 1980s, there have been numerous observations of extreme updrafts, gusts, and small-scale rotation in the eyewall of tropical cyclones (TCs). Research aircraft, dropsondes, and, more recently, mobile radars have collected these observations, most often from within the boundary layer. Previous studies have documented dropsondes associated with extreme gusts and updrafts, while others have discussed specific incidents of misoscale features in tropical cyclones. Several high-resolution numerical simulations of TCs have documented similar features. This study uses one such simulation from Worsnop et al. (2017). A small but intense tropical cyclone in a quiescent environment is simulated.

This simulation …


"Assessment Of The Likelihood To Stay Below 2 Degree Celsius Warming: Combining Modeling And Scenario Uncertainty.", Peter M. Booker Jan 2025

"Assessment Of The Likelihood To Stay Below 2 Degree Celsius Warming: Combining Modeling And Scenario Uncertainty.", Peter M. Booker

Electronic Theses & Dissertations (2024 - present)

ABSTRACT

Uncertainty in how much the Earth will warm in response to rising atmospheric CO₂ concentrations remains a major challenge for climate science and policy. In particular, estimates of equilibrium climate sensitivity (ECS) and transient climate response (TCR) directly affect projections of global mean surface temperature (GMST) and the allowable carbon budget for limiting warming to 2°C by 2100.

This study assesses the performance of a two-layer energy balance model (EBM) in reproducing TCR and ECS values under CMIP6 forcing scenarios, with a focus on SSP2-4.5. EBM outputs are compared against General Circulation Models (GCMs), and agreement is evaluated using …


Buoy-Based Eddy Covariance Drag Coefficient At A Near-Shore And Offshore Site, David P. Marcial Jan 2025

Buoy-Based Eddy Covariance Drag Coefficient At A Near-Shore And Offshore Site, David P. Marcial

Electronic Theses & Dissertations (2024 - present)

An eddy covariance (EC) flux system was integrated onto a Navy Oceanographic Meteorological Automatic Device (NOMAD) floating lidar buoy fitted for measuring the offshore wind resource. The EC flux system consisted of two sonic anemometers and an inertial measurement unit that together provided high-frequency (10 Hz) motion-corrected wind measurements. To assess possible impacts of flow distortion, EC momentum fluxes (10 min) were calculated in gravity-aligned, natural, and planar fit (PF) coordinate frames. The buoy was anchored near the Martha’s Vineyard Coastal Observatory Air-Sea Interaction Tower (ASIT; near-shore) for validation of the buoy-based EC fluxes against the fixed tower measurements before …


Cover Crops Can Reduce Greenhouse Gas Emissions From No-Till Maize In Southern Brazil: Insights From A Long-Term Field Experiment, Guilherme Rosa Da Silva, Adam J. Liska, Cimélio Bayer Jan 2025

Cover Crops Can Reduce Greenhouse Gas Emissions From No-Till Maize In Southern Brazil: Insights From A Long-Term Field Experiment, Guilherme Rosa Da Silva, Adam J. Liska, Cimélio Bayer

Adam Liska Papers

Brazil is one of the countries that has the most agricultural area under no-till (NT) management. This research study aims to evaluate life-cycle greenhouse gas (GHG) emissions from maize (M) grain production in agroecosystems that used different cover crops under NT management in southern Brazil. The data for this study were from a long-term 41-year field experiment in southern Brazil. The long-term experiment evaluated the effects of fallow (F) and cover crops (oat (O), vetch (V), cowpea (B), pigeon pea (P), and lablab (L)) on nitrous oxide and methane emissions and soil carbon (C) sequestration in maize agroecosystems. Five cropping …


The Response Of Tropopause Phenomena To Stratospheric Variability: Rossby Wave Breaking And Tropopause Polar Vortices, Cameron R. Paquette Jan 2025

The Response Of Tropopause Phenomena To Stratospheric Variability: Rossby Wave Breaking And Tropopause Polar Vortices, Cameron R. Paquette

Electronic Theses & Dissertations (2024 - present)

Variability in the high-latitude wintertime stratospheric flow, often referred to as the stratospheric polar vortex, can precede anomalous conditions in tropospheric flow on subseasonal-to-seasonal (S2S) timescales and impact surface weather. The range of stratospheric impacts on tropospheric conditions range from shifts in the North Atlantic storm tracks, formation of cold spells, and development of extreme precipitation. Impacts of stratospheric variability are known to persist for up to 60 days, providing ample windows of opportunity in forecasting on S2S timescales. This dissertation focuses on the stratospheric impacts on tropopause-level processes, such as Rossby wave breaking (RWB) events and tropopause polar vortices …


Light Absorbing Aerosol Interactions With Warm Clouds, Shreya Joshi Jan 2025

Light Absorbing Aerosol Interactions With Warm Clouds, Shreya Joshi

Dissertations, Master's Theses and Master's Reports

Atmospheric particles such as biomass-burning aerosols, including black carbon - are critical in altering the Earth's energy balance through interactions with light and clouds. Biomass-burning aerosols also contain organic carbon, a diverse mix of organic compounds. As these aerosols age, they evolve by interacting with other atmospheric species, including cloud water, leading to changes in particle morphology and the development of coatings that impact their lifetime and ability to interact with clouds and light.

Some biomass-burning aerosols serve as cloud condensation nuclei. When cloud water droplets form, the properties of the nucleating particles can change. Many clouds evaporate before precipitating, …