Atmospheric Sciences Commons^™

Production Of Singlet Oxygen (1O2) During The Photochemistry Of Aqueous Pyruvic Acid: The Effects Of Ph And Photon Flux Under Steady-State O2(Aq) Concentration, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

The photochemistry of pyruvic acid (PA) in aqueous atmospheric particles contributes to the production of secondary organic aerosols. This work investigates the fate of ketyl and acetyl radicals produced during the photolysis (λ ≥ 305 nm) of 5-100 mM PA under steady state [O₂(aq)] = 260 μM (1.0 ≤ pH ≤ 4.5) for photon fluxes between 1 and 10 suns. The radicals diffuse quickly into the water/air interface of microbubbles and react with dissolved O₂ to produce singlet oxygen (¹O₂^*). Furfuryl alcohol is used to trap and bracket the steady-state production of …

A Technical Overview Of The Kentucky Mesonet, Rezaul Mahmood, Megan Schargorodski, Stuart Foster, Andrew Quilligan

High Plains Regional Climate Center: Staff Publications

The Kentucky Mesonet is a research-grade weather and climate observing network with redundant sensors that monitors the near-surface atmosphere at 71 locations across Kentucky. The network measures temperature, precipitation, solar radiation, relative humidity, barometric pressure, and wind speed and direction every 5 min, with soil moisture and soil temperature measured every 30 min. In addition, it operates a camera at selected locations. All observations are transmitted via cellular modem every 5 min and become available to the general public through the World Wide Web within seconds after arrival at Kentucky Mesonet’s Network Operations Center. In between arriving at the IT …

Umphlett Qci Sept 2019, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Soil Moisture Conditions

Delayed/Prevented Planting

Forage Production

Infrastructure

Temperature

Precipitation

Measurement And Characterization Of Infrasound From A Tornado Producing Storm, Brian R. Elbing, Christopher E. Petrin, Matthew Van Den Broeke

Department of Earth and Atmospheric Sciences: Faculty Publications

A hail-producing supercell on 11 May 2017 produced a small tornado near Perkins, Oklahoma (35.97, –97.04) at 2013 UTC. Two infrasound microphones with a 59-m separation and a regional Doppler radar station were located 18.7 and 70 km from the tornado, respectively. Elevated infrasound levels were observed starting 7min before the verified tornado. Infrasound data below ~5Hz was contaminated with wind noise, but in the 5–50 Hz band the infrasound was independent of wind speed with a bearing angle that was consistent with the movement of the storm core that produced the tornado. During the tornado, a 75 dB peak …

Abrupt Climate Transitions, Christine J. Ramadhin

Dissertations, Theses, and Capstone Projects

The Earth’s climate system displays a long history of nonlinear abrupt transitions which have resulted in significant ecosystem disruption and are recorded in the geologic data. Today significant anthropogenic changes are occurring in many Earth systems that seem to be pushing these toward critical thresholds. Thus, increasing the possibility of a transition to alternative states which can have unfavorable consequences. Therefore, it becomes compelling to forecast when and how these transitions will occur so that decision-makers can devise appropriate strategies to avoid or cope with the effects of a changeover to a new alternative state. However, due to the highly …

Wind Flow Dynamics Over Complex Terrain, Eric Kutter

Dissertations, Theses, and Capstone Projects

Understanding the exchange of energy, moisture, and trace gases between the terrestrial biosphere and the atmosphere over complex terrain is a fundamental goal in achieving a complete model of global or regional climate. Net ecosystem exchange (NEE) of carbon dioxide is often a crucial input into climate models, and is also used as a means of validating regional model outputs. Calculations obtained from eddy flux tower data provide some of the best quality sources of NEE values; however, the standard formulation of the eddy covariance method is incomplete in terrain that includes common features such as hills, forests, cities, or …

Studying The Impact On Urban Health Over The Greater Delta Region In Egypt Due To Aerosol Variability Using Optical Characteristics From Satellite Observations And Ground-Based Aeronet Measurements, Wenzhao Li, Elham Ali, Islam Abou Al-Magd, Moustafa Mohamed Mourad, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

This research addresses the aerosol characteristics and variability over Cairo and the Greater Delta region over the last 20 years using an integrative multi-sensor approach of remotely sensed and PM10 ground data. The accuracy of these satellite aerosol products is also evaluated and compared through cross-validation against ground observations from the AErosol RObotic NETwork (AERONET) project measured at local stations. The results show the validity of using Multi-angle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra and Aqua platforms for quantitative aerosol optical depth (AOD) assessment as compared to Ozone Monitoring Instrument (OMI), Sea-viewingWide Field-of-view …

Global Sinusoidal Seasonality In Precipitation Isotopes, Scott T. Allen, Scott Jasechko, Wouter R. Berghuijs, Jeffrey M. Welker, Gregory R. Goldsmith, James W. Kirchner

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Quantifying seasonal variations in precipitation δ²H and δ¹⁸O is important for many stable isotope applications, including inferring plant water sources and streamflow ages. Our objective is to develop a data product that concisely quantifies the seasonality of stable isotope ratios in precipitation. We fit sine curves defined by amplitude, phase, and offset parameters to quantify annual precipitation isotope cycles at 653 meteorological stations on all seven continents. At most of these stations, including in tropical and subtropical regions, sine curves can represent the seasonal cycles in precipitation isotopes. Additionally, the amplitude, phase, and offset parameters of …

Climatological Changes: Meteorological Parameters Affecting The Spatial Redistribution Of U.S. Tornadoes, Ashley Dicks

The Journal of Purdue Undergraduate Research

Climatological changes in the environments of key meteorological parameters that affect Significant Tornado Days (SigTorDs) have been determined for two active tornado regions defined as Box α and Box β, centered, respectively, over Oklahoma and Alabama and their respective environs. The North American Regional Reanalysis data was selected for 1980–2013, providing two successive 17-year periods corresponding to the last 34 years of previous research findings that focused on the aforementioned regions. This data record also corresponds to an increasing surface air temperature trend for the continental United States. Period I (1980–1996) and Period II (1997–2013) defined the years of changing …

Toward Improved Understanding Of Black And Brown Carbon Radiative Impacts Over South Asia, Apoorva Pandey

McKelvey School of Engineering Graduate Student Theses & Dissertations

Atmospheric aerosols directly affect the Earth’s radiative budget by absorbing and scattering solar radiation. Carbonaceous aerosols constitute 20-90% of the global aerosol mass burden and are recognized by the Intergovernmental Panel on Climate Change as important drivers of direct radiative forcing (DRF). Aerosol radiative impacts have been implicated in regional atmospheric warming in South Asia: changing Indian monsoon patterns, and accelerating melting of the Himalayan glaciers. There are systematic global discrepancies between estimates of aerosol absorption optical depths derived from observations and those from climate models. Over South Asia, models predict six times lower aerosol absorption than ground-based observations, leading …

Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations, Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra K Dubey, Allison C Aiken, Rajan K Chakrabarty, Hans Moosmüller, Timothy B Onasch, Rahul A Zaveri, Barbara V Scarnato, Paulo Fialho, Claudio Mazzoleni

Michigan Tech Publications, Part 1

Soot particles form during combustion of carbonaceous materials and impact climate and air quality. When freshly emitted, they are typically fractal-like aggregates. After atmospheric aging, they can act as cloud condensation nuclei, and water condensation or evaporation restructure them to more compact aggregates, affecting their optical, aerodynamic, and surface properties. Here we survey the morphology of ambient soot particles from various locations and different environmental and aging conditions. We used electron microscopy and show extensive soot compaction after cloud processing. We further performed laboratory experiments to simulate atmospheric cloud processing under controlled conditions. We find that soot particles sampled after …

Comparison Between Fluid Simulation With Test Particles And 1 Hybrid Simulation For The Kelvin-Helmholtz Instability, Xuanye Ma, Katariina Nykyri, Brandon L. Burkholder, Rachel C. Rice, Peter A. Delamere, Bishwa Neupane

Publications

A quantitative investigation of plasma transport rate via the Kelvin‐Helmholtz (KH) instability can improve our understanding of solar‐wind‐magnetosphere coupling processes. Simulation studies provide a broad range of transport rates by using different measurements based on different initial conditions and under different plasma descriptions, which makes cross literature comparison difficult. In this study, the KH instability under similar initial and boundary conditions (i.e., applicable to the Earth's magnetopause environment) is simulated by Hall magnetohydrodynamics with test particles and hybrid simulations. Both simulations give similar particle mixing rates. However, plasma is mainly transported through a few big magnetic islands caused by KH‐driven …

Prediction Of Wind Power Density For Electricity Generation At Makambako, Tanzania Using Auto-Regression Integrated Moving Average (Arima) Model, Josam Samson, Reuben Kainkwa

Tanzania Journal of Science

Wind speed data used in this study were from Makambako and were recorded at a height of 10 m. In the analysis, the data were extrapolated to 80 m above ground level and wind speed from July to November were found to have an average value of 17.58 m/s. November was found to be the windiest month for the whole duration while the calm month was found to be March. The wind power density was found to be highest in the month of November for the whole study duration. The months of July to November have higher wind power density …

Monitoring Tropospheric Gases With Small Unmanned Aerial Systems (Suas) During The Second Cloudmap Flight Campaign, Travis J. Schuyler, Sean C. C. Bailey, Marcelo I. Guzman

Chemistry Faculty Publications

Small unmanned aerial systems (sUAS) are a promising technology for atmospheric monitoring of trace atmospheric gases. While sUAS can be navigated to provide information with higher spatiotemporal resolution than tethered balloons, they can also bridge the gap between the regions of the atmospheric boundary layer (ABL) sampled by ground stations and manned aircraft. Additionally, sUAS can be effectively employed in the petroleum industry, e.g., to constrain leaking regions of hydrocarbons from long gasoducts. Herein, sUAS are demonstrated to be a valuable technology for studying the concentration of important trace tropospheric gases in the ABL. The successful detection and quantification of …

An Observational Study Of Winter Weather-Related Traffic Crashes In Nebraska, Jacob Petr

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

The responsibilities of meteorologists have evolved over time from simply providing a forecast to needing to also understand how those predictions will impact society and then communicating those risks in a clear, concise, and consistent manner. Increased motor vehicle crash numbers due to adverse weather conditions represent one such impact worthy of further study. Snowfall, in particular, significantly increases the overall risk of a crash, which can result in extensive property damage, severe injuries, and even loss of life.This project seeks to supplement traffic crash information in Nebraska by assessing how snowfall impacts crashes across the state. Crash data were …

Non-Linear Magnetosphere-Ionosphere Interactions At High Latitudes, Beket Tulegenov

Doctoral Dissertations and Master's Theses

Non-linear, 3D electromagnetic coupling between the ionosphere and magnetosphere is investigated in this dissertation. The study is based on a non-linear, 3D, reduced magnetohydrodynamic model describing interaction between dispersive Alfven waves and the nightside high-latitude ionosphere. Results are presented from a numerical study of small-scale, intense magnetic field-aligned currents observed in the vicinity of the discrete auroral arc by the Magnetosphere-Ionosphere Coupling in the Alfven Resonator (MICA) sounding rocket launched from Poker Flat, Alaska, on 19 February 2012. The goal of the MICA project was to investigate the hypothesis that such currents can be produced inside the ionospheric Alfven resonator …

Analysis Of Hurricane Track Forecast Accuracy During The 2018 Season, Jonathan D. Unger

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Hurricane track forecasting has become more accurate in recent years due to technological advances in modeling methods. However, due to the complex nature of the relationship between oceanic and atmospheric variables and hurricane tracks, noteworthy errors in track prediction, especially for predictions several days into the future, still remain. In this study, two different methods of forecasting hurricane tracks are compared. Using the four United States landfalling hurricanes of the 2018 season as a sample, the official forecast tracks published by the National Hurricane Center (NHC) and hypothetical tracks based purely on climatology were mapped simultaneously with the preliminary best …

An Overview Of Handheld Sun Photometer Measurements Of Atmospheric Aerosols In New Orleans, Louisiana: A Case Study Of The Xavier University Study Site., M. Bradley, B. Sevalia, M. Gasseller

Faculty and Staff Publications

Aerosol optical depth (AOT) was measured at Xavier University of Louisiana (XULA, 29.96ᵒ N, 90.11° W and 3m above sea level) using a GLOBE handheld sun photometer. The measurements were done at two different wavelengths, 505nm and 625nm. The measured values were used to extrapolate the AOT values for wavelengths 667nm, 551nm, 532nm and 490nm at the XULA site. The measured and calculated AOT values were then compared with values from the nearest AERONET station at Wave CIS site 6 (AERONET, 28.87ᵒ N, 90.48° W and 33m above sea level), which is 60 miles south of XULA. In this study …

Odu Expert Invited To Testify At Legislative Hearing On Coastal Resilience, Sarah Huddle

News Items

No abstract provided.

An Estimation Of Lower Tropospheric Mixing Derived From Inverse Modeling Of Boundary Layer Water Vapor Isotopologues On Graciosa Island, Azores, Jacquelyn M. Delp

Earth and Planetary Sciences ETDs

Recent studies have shown water vapor isotopologues to be sensitive tracers of mixing processes that govern low-cloud feedback in climate models. In this study, we develop an inverse model (MBL Mix inverse model) that uses one year of isotope and humidity observations from Graciosa Island, Azores to estimate mixing for four seasons. We show the dry end-member of the model, the lower free troposphere (LFT), can be represented using Rayleigh fractionation. Isotope observations from Graciosa Island are compared to other field locations to discuss controls on isotopic variability other than mixing. Output from the MBL Mix inverse model shows the …

The Impact Of Energetic Neutral Particles Raining Down On The Thermosphere Due To Charge Exchange Reactions In The Upper Ionosphere And Polar Wind, Larry Gardner

Funded Research Records

No abstract provided.

An Estimation Of Lower Tropospheric Mixing Derived From Inverse Modeling Of Boundary Layer Water Vapor Isotopologues On Graciosa Island, Azores, Jacquelyn M. Delp

Earth and Planetary Sciences ETDs

Recent studies have shown water vapor isotopologues to be sensitive tracers of mixing processes that govern low-cloud feedback in climate models. In this study, we develop an inverse model (MBL Mix inverse model) that uses one year of isotope and humidity observations from Graciosa Island, Azores to estimate mixing for four seasons. We show the dry end-member of the model, the lower free troposphere (LFT), can be represented using Rayleigh fractionation. Isotope observations from Graciosa Island are compared to other field locations to discuss controls on isotopic variability other than mixing. Output from the MBL Mix inverse model shows the …

Droughtscape, Fall 2019, Cory Matteson

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

Quarterly drought summary

Quarterly drought impacts

Ranchers delayed response to drought

Drought Monitor celebrates 20 years

Drought Monitor state impact tables

Directorcontributesto U.N.droughtproject

Updated Drought Risk Atlas

New fact sheet lists recovery resources

Droughtscape, Summer 2019, Cory Matteson

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

Quarterly drought summary

Quarterly drought impacts

NDMC welcomes African visitors

Ready for Drought game debuts

U.S. Virgin Islands added to USDM

Australian programmer visits NDMC

Upcoming events

Partnerships with NDMC extended

Evaluation Of Viirs Nightfire Product And Comparison With Modis And Viirs Active Fire Products In A Russian Gas Flaring Region, Ambrish Sharma

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

Gas flaring is a commonly used practice for disposing of waste gases emerging from industrial oil drilling and production processes. It is a serious environmental and economic hazard with adverse impacts on air quality, climate, and the public health. Accurate determination of flare locations and estimation of associated emissions are therefore of prime importance. Recently developed Visible Infrared Imaging Radiometer Suite (VIIRS) Nightfire product (VNF) has shown remarkable efficiency in detecting gas flares globally, owing primarily to its use of Shortwave Infrared (SWIR) band in its detection algorithm. This study compares and contrast nocturnal hot source detection by VNF to …

Application Of The Optimal Estimation Method (Oem) To Retrieve Relative Humidity From Raman Lidar Backscatter Measurements., Shayamila N. Mahagammulla Gamage, Robert Sica, Alexander Haefele

Western Research Forum

Accurate measurements of relative humidity (RH) vertical profiles in the atmosphere is important for understanding the earth's weather and the climate system. RH represent the current state of the water vapor in the atmosphere with respect to the ambient air related to saturation. Even minor changes of the RH in the lower atmosphere has a large impact of the global circulation and cloud formation. Due to its high variability RH measurements in the lower atmosphere is significantly challenging. Raman lidar is one of the potential tools that can provide vertical profiles of RH. Typically, temperature and water vapor mixing ratios …

Integrated Raman Lidar And Microwave Radiometer Retrieval Of Atmospheric Water Vapor, Jeffrey Vankerkhove, Robert Sica, Alexander Haefele

Western Research Forum

Water vapor plays a critically important role in many atmospheric processes. However, it is poorly characterized throughout much of the atmosphere, particularly in the UTLS (Upper Troposphere Lower Stratosphere) region, due to lack of accurate measurements. Raman lidar boasts the capacity for excellent spatial and temporal resolution, but requires an external calibration. Microwave radiometers can be calibrated in absolute terms, but have poor height resolution. In this study, we introduce an integrated water vapor retrieval using an optimal estimation method, where the measurements from the Raman Lidar for Meteorological Observation (RALMO) and a RPG-HATPRO radiometer, both located at the MeteoSwiss …

Odu Study Puts The Estimated Price Tag Of A Major Hurricane In Hampton Roads At $40 Billion Or More, News @ Odu

News Items

No abstract provided.

Science Pubs Will Focus On Climate Related Resilience And Communication, Amy Matzke-Fawcett

News Items

No abstract provided.

Asian Long-Range Transport In Relation To Atmospheric Rivers In Northern California, Catherine Liu, Sen Chiao, Ju-Mee Ryoo

Faculty Publications, Meteorology and Climate Science

The study investigates the effect of aerosol long-range transport on precipitation over Northern California during atmospheric river (AR) events in the 2017 cold season (January–April). ARs in 2017 were one of the strongest to date, and the intense precipitation associated with the ARs resulted in flooding, destruction of property, and contamination of water supplies. The Aerosol Optical Depth (AOD) from Moderate Resolution Imaging Spectroradiometer (MODIS) data shows Asian dust traveling across the Northern Pacific Ocean along with AR events. Aerosol measurements in California, provided by the Interagency Monitoring of Protected Visual Environments (IMPROVE), show that more Asian dust tends to …