Atmospheric Sciences Commons^™

Turbulence In The Upper Levels Of Tropical Cyclones, Michaela Leigh Rosenmayer

Legacy Theses & Dissertations (2009 - 2024)

Turbulence in the cirrus canopy of tropical cyclones (TCs) can give an indication about the physical processes that occur in this expansive cloud deck. The low stability and/or large shear that likely coincides with turbulent layers can be produced by radiative forcing, convective forcing, and sublimation of frozen precipitation from the cirrus canopy. As a result, turbulence in the cirrus canopy can give an indication about the impact of various physical processes in tropical cyclones.

A Multiscale Analysis Of Major Transition Season Northeast Snowstorms, Rebecca Blair Steeves

Legacy Theses & Dissertations (2009 - 2024)

Major transition season Northeast snowstorms have the potential to cause widespread socioeconomic disruption in the form of transportation delays, infrastructure damage, and widespread power outages. Because heavy, wet snow tends to occur in transition season Northeast snowstorms, lesser accumulations can result in greater disruption than if the same accumulation occurred in winter season Northeast snowstorms. This study is motivated by the opportunity to improve scientific understanding and forecaster situational awareness of this class of snowstorms by means of a multiscale analysis. The multiscale analysis focuses on documenting: 1) the planetary-to-synoptic-scale flow patterns occurring prior to and during major transition season …

Linkages Between Tropopause Polar Vortices And The Development Of Cold Air Outbreaks Over Central And Eastern North America, Kevin Biernat

Legacy Theses & Dissertations (2009 - 2024)

Coherent vortices in the vicinity of the tropopause, referred to as tropopause polar vortices (TPVs), may be extracted from high latitudes in conjunction with high-latitude upper-level ridge amplification. Once extracted, TPVs may interact with and strengthen midlatitude jet streams, as well as act as precursor disturbances for the development of intense midlatitude cyclones. Cold pools that may accompany TPVs as they are transported to middle latitudes may lead to widespread cold air outbreaks (CAOs), which may result in significant socioeconomic impacts. The purpose of this study is to investigate 1) the equatorward transport of TPVs and cold pools to middle …

Evaluation Of Lightning Jumps As A Predictor Of Severe Weather In The Northeastern United States, Pamela Eck

Legacy Theses & Dissertations (2009 - 2024)

Severe weather events in the northeastern United States can be challenging to forecast, given how the evolution of deep convection can be influenced by complex terrain and the lack of quality observations in complex terrain. To supplement existing observations, this study explores using lightning to forecast severe convection in areas of complex terrain in the northeastern United States. A sudden increase in lightning flash rate by two standard deviations (2σ), also known as a lightning jump, may be indicative of a strengthening updraft and an increased probability of severe weather.

Determination And Analysis Of Dscovr-Eipc Satellite-Retrieved Radiance From Cloud Geometric And Optical Properties, Emily Christine Morgan

Legacy Theses & Dissertations (2009 - 2024)

Using simulations and numerical fitting, this work sought to describe the satellite-retrieved radiance of clouds as a function of their thermodynamic and optical properties. Subsequently, this understanding can then be used in a look-up-table to determine the properties of clouds imaged by the EPIC sensor in the NASA DSCOVR satellite. In this study, background oxygen absorption was modeled in a radiative transfer model and convolved with EPIC filter functions for two absorption-reference pairs for Oxygen A- and B-band. This absorption profile was established as the primary vertical coordinate in this study, leveraging the similarity principle to allow for intercomparison of …

Variations In Potential Vorticity Streamer Activity : Development Pathways, Environmental Impacts, And Links To Tropical Cyclone Activity In The North Atlantic Basin, Philippe Pierre Papin

Legacy Theses & Dissertations (2009 - 2024)

This dissertation examines the climatological occurrence of potential vorticity streamers (PVSs) during the tropical cyclone (TC) season that occur in the upper troposphere in the North Atlantic (NATL) basin, assessing how their variations in frequency, area, and intensity impact the synoptic environment, how they are induced by different synoptic-dynamic patterns, and how they modify TC activity and genesis pathways.

The Impact Snow Albedo Feedback Over Mountain Regions As Examined Through High-Resolution Regional Climate Change Experiments Over The Rocky Mountains, Theodore Letcher

Legacy Theses & Dissertations (2009 - 2024)

As the climate warms, the snow albedo feedback (SAF) will play a substantial role in shaping the climate response of mid-latitude mountain regions with transient snow cover. One such region is the Rocky Mountains of the western United States where large snow packs accumulate during the winter and persist throughout the spring. In this dissertation, the Weather Research and Forecast model (WRF) configured as a regional climate model is used to investigate the role of the SAF in determining the regional climate response to forced anthropogenic climate change. The regional effects of climate change are investigated by using the pseudo …

Impacts Of Internal Variability On Climate Trends In Large Ensemble Simulations By Two Climate Models, Christine Bloecker

Legacy Theses & Dissertations (2009 - 2024)

Internal climate variability (ICV) can influence trends in observations and model simulations over periods spanning decades, making it difficult to quantify the response of the climate system to external forcing. We analyze two large ensembles of climate simulations from 1950-2100 by two fully coupled climate models, namely the CanESM2 and CESM1, to quantify the effects of ICV on apparent trends in annual surface air temperature (T) and precipitation (P) over different time periods and regions. In comparison with observations, the CanESM2 overestimates the global T and P trends during 1979-2014 while they fall within the ICV-induced range of the CESM1. …

Sensitivity Of Meiyu Front To Aerosol Spatial Distribution Over Yangtze-Huai River Valley, Chu-Chun Huang

Legacy Theses & Dissertations (2009 - 2024)

The observed contrasts in both aerosol number and size associated with frequent north-polluted-south-clean (NPSC) conditions over Yangtze-Huai River Valley (YHRV) during the Meiyu season may induce different aerosol-cloud-radiation interactions within the region causing different evolution of the Meiyu system. This aspect was studied by conducting WRF sensitivity simulations with different configurations of north-south aerosol number and size contrasts. Results show that when the Meiyu system develops at YHRV, more aerosols in the north (than the south) cause more but smaller cloud droplets to form, resulting in stronger radiative cooling at north part of the Meiyu system. Subsequently, the differential cooling …

Understanding Predictive Skill Of Arctic Sea Ice And Its Linkage With Mid-Latitude Weather And Climate In The Ncep Climate Forecast System, Colleen Mchugh

Legacy Theses & Dissertations (2009 - 2024)

Arctic climate is undergoing significant change, particularly rapid decline of sea ice. Arctic sea ice plays an important role in local, regional, and global climate through a variety of physical processes as seen in observational analysis as well as modeling studies. Recent research suggested that decreasing autumn and winter Arctic sea ice extent (SIE) has been shown to have an effect on mid-latitude weather patterns during the winter months. Therefore, accurate forecasts of Arctic sea ice extent and the associated teleconnections with the mid-latitudes are important for accurate seasonal climate prediction. The NCEP Climate Forecast System version 2 (CFSv2) is …

Agricultural Drought Transition Periods In The United States Corn Belt Region, Nicholas Joseph Schiraldi

Legacy Theses & Dissertations (2009 - 2024)

Agricultural drought in the U.S. Corn Belt region (CBR) has tremendous global socioeconomic implications. Unfortunately, the weather and climate factors that contribute to transition events toward or away from such droughts, and how well those factors are predicted, are poorly understood. This dissertation focuses on the atmospheric circulation signals associated with agricultural drought transitions periods in the CBR that evolve over 20 and 60 days, and how well those circulation signals are predicted on seasonal to sub-seasonal time scales.

Examining Variability In Model Skill During The 7 January 2013 Sudden Stratospheric Warming Event, Jonathan Lee Blufer

Legacy Theses & Dissertations (2009 - 2024)

Recent analyses of numerical weather prediction models have shown that stratospheric regime changes (e.g. strong and weak vortex events) are not skillfully predicted at medium-range lead times. Motivated by these recent analyses, this thesis investigates the sources of variability in stratospheric forecast skill amongst several operational models initiated at different lead times prior to the 7 January 2013 sudden stratospheric warming (SSW). This study extends upon a previous analysis by the Stratospheric Network for the Assessment of Predictability (SNAP), which concluded that a change in forecast lead-time from 15 to 10 days increased model skill in predicting the 2013 SSW …

Investigating The Effects Of Ice-Forming Saharan Dust Aerosols On Tropical Deep Convection Using Spectral Bin Microphysics, Matthew Scott Gibbons

Legacy Theses & Dissertations (2009 - 2024)

Aerosol effects on cloud and precipitation formation remain a significant source of uncertainty in the study of weather and climate. Aerosols can impact cloud and precipitation formation by functioning as cloud condensation nuclei (CCN), giant cloud condensation nuclei (GCCN) and/or ice nuclei (IN) affecting subsequent cloud microphysical processes. Aerosol effects on clouds are tightly interconnected with cloud dynamic and thermodynamic variables, some of which are currently impossible or infeasible to observe with existing sensors. Numerical models can be used to untangle aerosols effects from cloud dynamics and thermodynamics, but model results can be affected by the complexity of the parameterizations …

Tropical Cyclone Intensification Under Moderate Vertical Wind Shear, Rosimar Rios-Berrios

Legacy Theses & Dissertations (2009 - 2024)

Deep-layer (200–850 hPa) vertical wind shear is generally an inhibiting factor for tropical cyclone intensification. Multiple studies—ranging from case studies to climatological analyses—have consistently shown that the chances of tropical cyclone intensification decrease with increasing vertical wind shear magnitude. However, tropical cyclones can intensify under moderate shear—the range of shear magnitudes that are neither too weak to have negligible influence on intensity nor too strong to completely halt intensification. Intensity, track, and precipitation forecasts of tropical cyclones under moderate shear can be highly uncertain; therefore, explaining how tropical cyclones evolve under seemingly unfavorable conditions is an important step towards improved …

Evaluation Of Extratropical Cyclone Precipitation In The North Atlantic Basin: An Analysis Of Era-Interim, Wrf, And Two Cmip5 Models, James F. Booth, Catherine M. Naud, Jeff Willison

Publications and Research

The representation of extratropical cyclones (ETCs) precipitation in general circulation models (GCMs) and a weather research and forecasting (WRF) model is analyzed. This work considers the link between ETC precipitation and dynamical strength and tests if parameterized convection affects this link for ETCs in the North Atlantic Basin. Lagrangian cyclone tracks of ETCs in ERA-Interim reanalysis (ERAI), the GISS and GFDL CMIP5 models, and WRF with two horizontal resolutions are utilized in a compositing analysis. The 20-km resolution WRF model generates stronger ETCs based on surface wind speed and cyclone precipitation. The GCMs and ERAI generate similar composite means and …

Remote Sensing Observation Of Annual Dust Cycles And Possible Causality Of Kawasaki Disease Outbreaks In Japan, Hesham El-Askary, Nick Lahaye, Erik J. Linstead, William A. Sprigg, Magdi Yacoub

Mathematics, Physics, and Computer Science Faculty Articles and Research

Kawasaki disease (KD) is a rare vascular disease that, if left untreated, can result in irreparable cardiac damage in children. While the symptoms of KD are well-known, as are best practices for treatment, the etiology of the disease and the factors contributing to KD outbreaks remain puzzling to both medical practitioners and scientists alike. Recently, a fungus known as Candida, originating in the farmlands of China, has been blamed for outbreaks in China and Japan, with the hypothesis that it can be transported over long ranges via different wind mechanisms. This paper provides evidence to understand the transport mechanisms …

Quantifying Carbonyl Sulfide And Other Sulfur-Containing Compounds Over The Santa Barbara Channel, Julia Black

Scripps Senior Theses

Carbonyl sulfide (OCS) is emitted to the atmosphere through the outgassing of ocean surface waters. OCS is also the primary source of sulfur-containing compounds in the stratosphere and contributes to the formation of the stratospheric sulfate layer, an essential controller of the radiative balance of the atmosphere. During the 2016 Student Airborne Research Program (SARP), 15 whole air samples were collected on the NASA DC-8 aircraft over the Santa Barbara Channel. Five additional surface samples were taken at various locations along the Santa Barbara Channel. The samples were analyzed using gas chromatography in the Rowland-Blake lab at UC Irvine, and …

Pathways And Supply Of Dissolved Iron In The Amundsen Sea (Antarctica), P. St-Laurent, P. L. Yager, R. M. Sherrell, S. E. Stammerjohn, M. S. Dinniman

CCPO Publications

Numerous coastal polynyas fringe the Antarctic continent and strongly influence the productivity of Antarctic shelf systems. Of the 46 Antarctic coastal polynyas documented in a recent study, the Amundsen Sea Polynya (ASP) stands out as having the highest net primary production per unit area. Incubation experiments suggest that this productivity is partly controlled by the availability of dissolved iron (dFe).As a first step toward understanding the iron supply of the ASP, we introduce four plausible sources of dFe and simulate their steady spatial distribution using conservative numerical tracers. The modeled distributions replicate important features from observations including dFe maxima at …

Observations And Operational Model Simulations Reveal The Impact Of Hurricane Matthew (2016) On The Gulf Stream And Coastal Sea Level, Tal Ezer, Larry P. Atkinson, Robert Tuleya

CCPO Publications

In October 7–9, 2016, Hurricane Matthew moved along the southeastern coast of the U.S., causing major flooding and significant damage, even to locations farther north well away from the storm’s winds. Various observations, such as tide gauge data, cable measurements of the Florida Current (FC) transport, satellite altimeter data and high-frequency radar data, were analyzed to evaluate the impact of the storm. The data show a dramatic decline in the FC flow and increased coastal sea level along the U.S. coast. Weakening of the Gulf Stream (GS) downstream from the storm’s area contributed to high coastal sea levels farther north. …

Laboratory, Computational And Theoretical Investigations Of Ice Nucleation And Its Implications For Mixed Phase Clouds, Fan Yang

Dissertations, Master's Theses and Master's Reports

Ice particles in atmospheric clouds play an important role in determining cloud lifetime, precipitation and radiation. It is therefore important to understand the whole life cycle of ice particles in the atmosphere, e.g., where they come from (nucleation), how they evolve (growth), and where they go (precipitation). Ice nucleation is the crucial step for ice formation, and in this study, we will mainly focus on ice nucleation in the lab and its effect on mixed-phase stratiform clouds.

In the first half of this study, we investigate the relevance of moving contact lines (i.e., the region where three or more phases …

New And Improved Infra-Red Absorption Cross Sections And Ace-Fts Retrievals Of Carbon Tetrachloride (Ccl4), Jeremy J. Harrison, Christopher D. Boone, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Carbon tetrachloride (CCl₄) is one of the species regulated by the Montreal Protocol on account of its ability to deplete stratospheric ozone. As such, the inconsistency between observations of its abundance and estimated sources and sinks is an important problem requiring urgent attention (Carpenter et al., 2014) [5]. Satellite remote-sensing has a role to play, particularly limb sounders which can provide vertical profiles into the stratosphere and therefore validate stratospheric loss rates in atmospheric models. This work is in two parts. The first describes new and improved high-resolution infra-red absorption cross sections of carbon tetrachloride/dry synthetic air over …

The Hitran2016 Molecular Spectroscopic Database, I. E. Gordon, L. S. Rothman, C. Hill, R. V. Kochanov, Y. Tan, P. F. Bernath, M. Birk, V. Boudon, A. Campargue, K. V. Chance

Chemistry & Biochemistry Faculty Publications

This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional …

Field Data Collection And Analysis Of Tornadic Environment Enhancement By Topography Along The Sand Mountain Plateau, Preston Pangle

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Clustering Of Lightning Strokes To Study Lightning And Terrestrial Gamma-Ray Flashes (Tgfs), Elena Pradhan

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Iron Reduction In Soot, Hector Casique

All Master's Theses

Ferrous iron (Fe(II)) has been implicated as one contributor in the generation of reactive oxygen species (ROS) from ambient particles emitted during the incomplete combustion of fossil and biomass fuels. Although ROS are known to induce unhealthy oxidative stress in cellular systems, the mechanisms of Fe(II) formation and stabilization in aerosol particles are still not well understood. Here, we investigate the role of soot on Iron reduction from Fe(III) to Fe(II), under various conditions including those encountered in the tailpipe of a vehicle. Aqueous leaching experiments of soot-hematite mixtures were carried out while analyzing for Fe(II) spectrophotometrically, and changes in …

Upper Water Structure And Mixed Layer Depth In Tropical Waters: The Seats Station In The Northern South China Sea, Jen-Hua Tai, George T. F. Wong, Xiaoju Pan

OES Faculty Publications

The variability of the upper water hydrographic structure, the efficacy of the different schemes for estimating the mixed layer depth (MLD), the inter-comparability estimation of the MLDs and diurnal and intra-annual MLD climatology in the tropical waters in the northern South China Sea were accessed in 702 depth-profiles of potential temperature (θ) and salinity collected in 64 cruises between 17.5 and 18.5°N and 115.3 and 116.3°E from 1997 to 2013. The hydrographic structure may be subdivided into three principal types: the classical type, with quasi-isopycnal surface mixed layer followed by an abrupt increase in the depth-gradient in θ and potential …

Assessing The Optimized Precision Of The Aircraft Mass Balance Method For Measurement Of Urban Greenhouse Gas Emission Rates Through Averaging, Alexie M F Heimburger, Rebecca M. Harvey, Paul B. Shepson, Brian H. Stirm, Chloe Gore, Jocelyn Turnbull, Maria Obiminda L. Cambaliza, Olivia E. Salmon, Anna-Elodie M. Kerlo, Tegan Lavoie, Kenneth J. Davis, Thomas Lauvaux, Anna Karion, Colm Sweeney, W Alan Brewer, R Michael Hardesty, Kevin R. Gurney

Physics Faculty Publications

To effectively address climate change, aggressive mitigation policies need to be implemented to reduce greenhouse gas emissions. Anthropogenic carbon emissions are mostly generated from urban environments, where human activities are spatially concentrated. Improvements in uncertainty determinations and precision of measurement techniques are critical to permit accurate and precise tracking of emissions changes relative to the reduction targets. As part of the INFLUX project, we quantified carbon dioxide (CO2), carbon monoxide (CO) and methane (CH4) emission rates for the city of Indianapolis by averaging results from nine aircraft-based mass balance experiments performed in November-December 2014. Our goal was to assess the …

Gridded Snow Water Equivalent Reconstruction For Utah Using Forest Inventory And Analysis Tree-Ring Data, Daniel Barandiaran, Shih-Yu (Simon) Wang, R. Justin Derose

Plants, Soils, and Climate Faculty Publications

Snowpack observations in the Intermountain West are sparse and short, making them difficult for use in depicting past variability and extremes. This study presents a reconstruction of April 1 snow water equivalent (SWE) for the period of 1850–1989 using increment cores collected by the U.S. Forest Service, Interior West Forest Inventory and Analysis program (FIA). In the state of Utah, SWE was reconstructed for 38 snow course locations using a combination of standardized tree-ring indices derived from both FIA increment cores and publicly available tree-ring chronologies. These individual reconstructions were then interpolated to a 4-km grid using an objective analysis …

Dynamical Processes Of Gravity Waves Propagation And Dissipation, And Statistical Characteristics Of Their Momentum Flux In The Mesosphere And Lower Thermosphere, Bing Cao

Doctoral Dissertations and Master's Theses

The mesosphere and lower thermosphere (MLT) (⇠80–110 km) is dominated by abundant atmospheric waves, of which gravity waves are one of the least understood due to large varieties in wave characteristics as well as potential sources. Gravity waves play an important role in the atmosphere by influencing the thermal balance and helping to drive the global circulation. But due to their sub-grid scale, the effects of gravity waves in General Circulation Models (GCMs) are mostly parameterized. The investigations of gravity waves in this dissertation are from two perspectives: the dynamical processes of gravity wave propagation and dissipation in the MLT …

Rapid Adaptive Responses To Climate Change In Corals, Gergely Torda, Jennifer M. Donelson, Manuel Aranda, Daniel J. Barshis, Line Bay, Michael L. Berumen, David G. Bourne, Neal Cantin, Sylvain Foret, Mikhail Matz

Biological Sciences Faculty Publications

Pivotal to projecting the fate of coral reefs is the capacity of reef-building corals to acclimatize and adapt to climate change. Transgenerational plasticity may enable some marine organisms to acclimatize over several generations and it has been hypothesized that epigenetic processes and microbial associations might facilitate adaptive responses. However, current evidence is equivocal and understanding of the underlying processes is limited. Here, we discuss prospects for observing transgenerational plasticity in corals and the mechanisms that could enable adaptive plasticity in the coral holobiont, including the potential role of epigenetics and coral-associated microbes. Well-designed and strictly controlled experiments are needed to …