An Analysis Of The Linkages Between Large-Scale Flow Regime Transitions On The Spatiotemporal Distribution Of Clustered Extratropical Cyclone Events Over The Northern Hemisphere,
2018
University at Albany, State University of New York
An Analysis Of The Linkages Between Large-Scale Flow Regime Transitions On The Spatiotemporal Distribution Of Clustered Extratropical Cyclone Events Over The Northern Hemisphere, Eric Merton John Bunker
Legacy Theses & Dissertations (2009 - 2024)
An Analysis of the Linkages Between Large-Scale Flow Regime Transitions on the Spatiotemporal Distribution of Clustered Extratropical Cyclone Events over the Northern Hemisphere
What Affects The Phase Speed Of Madden-Julian Oscillation Convection,
2018
University at Albany, State University of New York
What Affects The Phase Speed Of Madden-Julian Oscillation Convection, Robert Setzenfand
Legacy Theses & Dissertations (2009 - 2024)
The Madden-Julian Oscillation (MJO) is the main source of convective and circulation variability on intraseasonal timescales and planetary spatial scales within the tropics. Although the phase speed of the MJO convective envelope is often stated as 5 m s–1, MJO events that occur over the Indo-Pacific warm pool can have a range of phase speeds. This study uses a wavelet to identify MJO convective events with specified phase speeds in a satellite-derived outgoing longwave radiation (OLR) dataset during boreal winter. The wavelet-filtered OLR index is then regressed against basic meteorological variables to extract information about MJO events or signals propagating …
Predictability Of African Easterly Waves In An Operational Ensemble Prediction System,
2018
University at Albany, State University of New York
Predictability Of African Easterly Waves In An Operational Ensemble Prediction System, Travis J. Elless
Legacy Theses & Dissertations (2009 - 2024)
African easterly waves (AEWs) are the primary synoptic-scale weather feature found in sub-Saharan Africa during boreal summer. Many studies have used observations and idealized models to highlight processes associated with the movement and growth of AEWs, yet there have been few studies documenting the performance of operational ensemble prediction systems (EPSs) for these phenomena. Here, the predictability of AEWs in ECMWF EPS forecasts is assessed during two periods of enhanced AEW activity (July--September 2007--2009 and 2011--2013). Specifically, AEW predictability is analyzed through three main areas of focus: 1) verifying AEW position and intensity forecasts, and assessing their relation to convective …
Projected Changes In Climate, Elevation-Dependent Warming, And Extreme Events Over Continental Ecuador For The Period 2041-2070,
2018
University at Albany, State University of New York
Projected Changes In Climate, Elevation-Dependent Warming, And Extreme Events Over Continental Ecuador For The Period 2041-2070, Oscar Chimborazo
Legacy Theses & Dissertations (2009 - 2024)
The climate over Ecuador is complex due to several interacting factors, such as its location at the equator, the Andean topography, and several modes of internal variability, including the El Niño–Southern Oscillation (ENSO), affecting the region. In addition, the rapid increase in greenhouse gas concentrations will continue to affect both the mean state and climate variability in Ecuador over the coming decades. Hence, a thorough understanding of both natural and anthropogenic forcings and how they combine to influence Ecuadorian climate is a necessity for decision-making and implementation of adequate adaptation measures. However, the lack of observational data, both in space …
Whole-Canopy Net Ecosystem Exchange And Water Use Efficiency In An Intermittent-Light Environment -- Dynamic Approach,
2018
University at Albany, State University of New York
Whole-Canopy Net Ecosystem Exchange And Water Use Efficiency In An Intermittent-Light Environment -- Dynamic Approach, Sergey Nikolayevich Kivalov
Legacy Theses & Dissertations (2009 - 2024)
An observed 20-30% increase in forest net ecosystem exchange (NEE) on partly cloudy days is often attributed to there being more uniform canopy illumination by diffuse radiation when clouds are present. However, the sky on such days is typically populated by fair-weather cumulus clouds, bringing dynamically changing shadow-to-light conditions on the order of minutes to the forest, with radiation alternating from 1000 W m^-2 in the clear sky to less than 400 W m^-2 in under-cloud shadows. These dynamically changing conditions cannot be investigated by the conventional time-averaged eddy-covariance flux method, which requires nearly steady-state turbulent conditions over much longer …
Polar Ozone Depletion: Mario J. Molina,
2018
Parkland College
Polar Ozone Depletion: Mario J. Molina, Kirsten Oberg
Natural Sciences Student Research Presentations
This poster for the Natural Sciences Poster Session at Parkland College features the contribution of Mario J. Molina to the field of atmospheric chemistry, especially in regards to the formation and decomposition aspects of the ozone layer.
Biomass Burning In The Conterminous United States: A Comparison And Fusion Of Active Fire Observations From Polar-Orbiting And Geostationary Satellites For Emissions Estimation,
2018
South Dakota State University
Biomass Burning In The Conterminous United States: A Comparison And Fusion Of Active Fire Observations From Polar-Orbiting And Geostationary Satellites For Emissions Estimation, Fangjun Li
Electronic Theses and Dissertations
Biomass burning is an important source of atmospheric greenhouse gases and aerosol emissions that significantly influence climate and air quality. Estimation of biomassburning emissions (BBE) has been limited to the conventional method in which parameters (i.e., burned area and fuel load) can be challenging to quantify accurately. Recent studies have demonstrated that the rate of biomass combustion is a linear function of fire radiative power (FRP), the instantaneous radiative energy released from actively burning fires, which provides a novel pathway to estimate BBE. To obtain accurate and timely BBE estimates for near real-time applications (i.e., air quality forecast), the satellite …
Recommissioning Reddi: Reviving A Doppler Asymmetric Spatial Heterodyne Spectrometer For Observing Thermospheric Winds,
2018
Embry-Riddle Aeronautical University
Recommissioning Reddi: Reviving A Doppler Asymmetric Spatial Heterodyne Spectrometer For Observing Thermospheric Winds, Robert Kallio
Doctoral Dissertations and Master's Theses
The REd-line DASH Demonstration Instrument (REDDI) was designed to prove that a Doppler Asymmetric Spatial Heterodyne (DASH) spectrometer could be used to accurately measure thermospheric winds by observing the Doppler shift of the 630nm emission of oxygen in the thermosphere. In 2015, we began a project to redesign the input optics of REDDI to repurpose the instrument from a demonstration unit to a long duration instrument. Integration of REDDI into the INSpIRe (Investigating Near-Space Interaction Regions) trailer at Embry-Riddle Aeronautical University (ERAU), Daytona Beach, began in 2016 with assembly of the new input optics in 2017. REDDI and INSpIRe will …
Spectral Signatures Of Submicron Scale Light-Absorbing Impurities In Snow And Ice Using Hyperspectral Microscopy,
2018
University of Bern
Spectral Signatures Of Submicron Scale Light-Absorbing Impurities In Snow And Ice Using Hyperspectral Microscopy, Farra Dal Anna, Susan Kaspari, James Beach, Thomas D. Bucheli, Michael Schaepman, Margit Schwikowski
Geological Sciences Faculty Scholarship
Light-absorbing impurities (LAI) can darken snow and ice surfaces, reduce snow/ice albedo and accelerate melt. Efforts to allocate the relative contribution of different LAI to snow/ice albedo reductions have been limited by uncertainties in the optical properties of LAI. We developed a new method to measure LAI spectral reflectance at the submicron scale by modifying a Hyperspectral Imaging Microscope Spectrometer (HIMS). We present the instrument’s internal calibration, and the overall small influence of a particle’s orientation on its measured reflectance spectrum. We validated this new method through the comparison with a field spectroradiometer by measuring different standard materials. Measurements with …
Comparison Of Various Mean Field Formulations For Retrieving Refractive Indices Of Aerosol Particles Containing Inclusions,
2018
University of Central Arkansas
Comparison Of Various Mean Field Formulations For Retrieving Refractive Indices Of Aerosol Particles Containing Inclusions, Kristin S. Dooley, Jessica Deyoung
Journal of the Arkansas Academy of Science
Application of effective medium approximation (EMA) methods to two-component systems are presented. Systems studied are composed of water, sulfate, soot, and dust as these are commonly encountered atmospheric aerosol components. Atmospheric models often employ EMAs to include internally mixed aerosols without the computational burden of exact theory. In the current work, several types of mixing rules (Maxwell-Garnet, Bruggeman, and coherent potential approximation) have been applied to various two-component internally mixed particles at 550 nm using volume fractions of the minor component below 0.1. As expected, results show that the formulations tested produce very similar effective refractive indices indicating that electric …
Global Sea-Level Budget 1993-Present,
2018
Old Dominion University
Global Sea-Level Budget 1993-Present, Wcrp Global Sea Level Budget Group, Benjamin Hamlington
CCPO Publications
Global mean sea level is an integral of changes occurring in the climate system in response to unforced climate variability as well as natural and anthropogenic forcing factors. Its temporal evolution allows changes (e.g.,acceleration) to be detected in one or more components. Study of the sea-level budget provides constraints on missing or poorly known contributions, such as the unsurveyed deep ocean or the still uncertain land water component. In the context of the World Climate Research Programme Grand Challenge entitled "Regional Sea Level and Coastal Impacts", an international effort involving the sea-level community worldwide has been recently initiated with the …
A Comparative Study Characterizing Traffic Related Air Pollutant Concentrations At Near-Road Communities In El Paso, Texas,
2018
University of Texas at El Paso
A Comparative Study Characterizing Traffic Related Air Pollutant Concentrations At Near-Road Communities In El Paso, Texas, Adan Rangel
Open Access Theses & Dissertations
Numerous scientific studies have demonstrated the influence of traffic related air pollution at near-road communities and the associated health risks for these populations. This study uses on-site air quality monitors to characterize air pollutants at near-road schools in El Paso, TX to understand children's exposure to traffic-related air pollutants. Ambient air monitoring stations were installed at Coldwell Elementary, Bliss Elementary, and a residential house located in close proximity to major inter-state roadways. In this study, air quality data for PM2.5, PM10, NO2, and O3 was collected over a period of nine weeks in Fall 2018. The spatial and temporal variability …
Mls Measurements Of Stratospheric Hydrogen Cyanide During The 2015-2016 El Niño Event,
2018
Old Dominion University
Mls Measurements Of Stratospheric Hydrogen Cyanide During The 2015-2016 El Niño Event, Hugh C. Pumphrey, Norbert Glatthor, Peter F. Bernath, Christopher D. Boone, James W. Hannigan, Ivan Ortega, Nathaniel J. Livesey, William G. Read
Chemistry & Biochemistry Faculty Publications
It is known from ground-based measurements made during the 1982-1983 and 1997-1998 El Niño events that atmospheric hydrogen cyanide (HCN) tends to be higher during such years than at other times. The Microwave Limb Sounder (MLS) on the Aura satellite has been measuring HCN mixing ratios since launch in 2004; the measurements are ongoing at the time of writing. The winter of 2015- 2016 saw the largest El Niño event since 1997-1998. We present MLS measurements of HCN in the lower stratosphere for the Aura mission to date, comparing the 2015- 2016 El Niño period to the rest of the …
Stratospheric Ozone And Hcl Trends (2000-2016): How Significant Is Recent Growth In Chlorinated Very Short-Lived Substances,
2018
Lancaster Environment Centre
Stratospheric Ozone And Hcl Trends (2000-2016): How Significant Is Recent Growth In Chlorinated Very Short-Lived Substances, Ryan Hossaini, Martyn Chipperfield, Peter Bernath, Anton Fernando, Sandip Dhomse, Wuhu Feng
Chemistry & Biochemistry Faculty Publications
[Introduction] Chlorinated very short-lived substances (VSLS), such as dichloromethane (CH2CL2), chloroform (CHCl3) and perchloroethylene (C2Cl4) constitute a small, but growing source of stratospheric chlorine (e.g. WMO, 2014). High-altitude aircraft observations provide some constraint on the stratospheric source gas injection of chlorine from these compounds, though product gas injection - from VSLS-derived phosgene and HCl produced in the troposphere - is uncertain. Furthermore, in addition to an overall paucity of atmospheric VSLS observations, the impact of VSLS growth on stratospheric composition trends in the recent past (e.g. ozone, HCl) remains poorly constrained.
Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia,
2018
Old Dominion University
Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia, Nikolai F. Zobov, Phillip A. Coles, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Robert J. Hargreaves, Peter F. Bernath, Jonathan Tennyson, Sergei N. Yurchenko, Oleg L. Polyansky
Chemistry & Biochemistry Faculty Publications
Room temperature NH3 absorption spectra recorded at the Kitt Peak National Solar Observatory in 1980 are analyzed. The spectra cover two regions in the visible: 15,200 - 15,700 cm-1 and 17,950 - 18,250 cm-1. These high overtone rotation-vibration spectra are analyzed using both combination differences and variational line lists. Two variational line lists were computed using the TROVE nuclear motion program: one is based on an ab initio potential energy surface (PES) while the other used a semi-empirical PES. Ab initio dipole moment surfaces are used in both cases. 95 energy levels with J = 1 …
Abrupt Changes In Wind Conditions At The Memphis International Airport,
2018
University of Alabama in Huntsville
Abrupt Changes In Wind Conditions At The Memphis International Airport, Nicholas E. Johnson
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
Assessing The Effects Of Storm Depth On Tds Height Interpretation In Tornado Intensity Estimation,
2018
University of Alabama in Huntsville
Assessing The Effects Of Storm Depth On Tds Height Interpretation In Tornado Intensity Estimation, Andrew Lee
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
Record Setting: The Origins Of Extreme Hail On 19 March 2018 During Vortex-Se,
2018
University of Alabama in Huntsville
Record Setting: The Origins Of Extreme Hail On 19 March 2018 During Vortex-Se, Dean Meyer
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
Long-Term Changes In Extreme Air Pollution Meteorology And Implications For Air Quality,
2018
Michigan Technological University
Long-Term Changes In Extreme Air Pollution Meteorology And Implications For Air Quality, Pei Hou
Dissertations, Master's Theses and Master's Reports
Extreme air pollution meteorology, such as heat waves, temperature inversions, and atmospheric stagnation episodes, can significantly affect air quality. In this study, we analyze their long-term trends and the potential impacts on air quality. The significant increasing trends for the occurrences of extreme meteorological events in 1951-2010 are identified with the reanalysis data, especially over the continental regions. A statistical analysis combining air quality data and meteorological data indicates strong sensitivities of air quality, including both average air pollutant concentrations and high pollution episodes, to extreme meteorological events. Results also show significant seasonal and spatial variations in the sensitivity of …
Evaluating The Effectiveness Of Current Atmospheric Refraction Models In Predicting Sunrise And Sunset Times,
2018
Michigan Technological University
Evaluating The Effectiveness Of Current Atmospheric Refraction Models In Predicting Sunrise And Sunset Times, Teresa Wilson
Dissertations, Master's Theses and Master's Reports
The standard value for atmospheric refraction on the horizon of 34', used in all publicly available sunrise and sunset calculators, is found to be inadequate. The assumptions behind atmospheric models that predict this value fail to account for real meteorological conditions. The result is an uncertainty of one to five minutes in sunrise and sunset predictions at mid-latitudes (0° - 55° N/S). A sunrise/set calculator that interchanges the refraction component by varying the refraction model was developed. Two atmospheric refraction models of increasing complexity were tested along with the standard value. The predictions were compared with data sets of observed …
