Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 34

Full-Text Articles in Physical Sciences and Mathematics

The Simulated Sensitivity Of The North American Monsoon At Convection-Permitting Scales, Brendan Wallace Dec 2022

The Simulated Sensitivity Of The North American Monsoon At Convection-Permitting Scales, Brendan Wallace

Legacy Theses & Dissertations (2009 - 2024)

The North American Monsoon (NAM) is a major contributor to annual rainfall for large portions of the North American Southwest. Much of the prior work examining the NAM using numerical models has been done at scales exceeding 20-km grid spacing. At these coarse scales, unresolved processes and poorly resolved geographic features can impact model performance. This can present a problem when simulating the NAM particularly with regard to orographic precipitation, precipitation on sub-daily timescales, and land surface-atmosphere interactions. This dissertation seeks to better understand the NAM through examination of several sets of convection-permitting regional climate model output. The primary goal …


Dynamic Impacts Of Hadley Circulation On Saharan Desert Warming Amplification, Alejandro Manuel Ayala Jan 2022

Dynamic Impacts Of Hadley Circulation On Saharan Desert Warming Amplification, Alejandro Manuel Ayala

Legacy Theses & Dissertations (2009 - 2024)

Changes in temperature due to climate change are not spatially uniform, and deserts and other drylands, which are greatly underrepresented in climate studies, are warming at a much faster rate than much of the globe with increasing concentrations of greenhouse gases. This strong warming amplification over deserts, termed Desert Amplification (DA), is most pronounced over the world’s largest and driest Sahara Desert and the Arabian Peninsula. The Sahara and Arabian deserts are formed in the subtropical subsiding branch of the Hadley Circulation (HC) and so the changes in large-scale subsidence associated with adiabatic heating could impact the DA dynamically. While …


The Surface Heating Efficiency Of Atmospheric Energy Flux Events During Arctic Winter, Christopher Joseph Cardinale Jan 2022

The Surface Heating Efficiency Of Atmospheric Energy Flux Events During Arctic Winter, Christopher Joseph Cardinale

Legacy Theses & Dissertations (2009 - 2024)

The flux of moist static energy (MSE) into the polar regions plays a key role in the energy budget and climate of the polar regions. While usually studied from a vertically integrated perspective (Fwall), this dissertation examines its vertical structure, using the NASA-MERRA-2 reanalysis to compute climatological and anomalous fluxes of sensible, latent, and potential energy across 70◦N and 65◦S. This dissertation applies an energy budget analysis to winter-season synoptic periods of increased tropospheric (Ftrop) and stratospheric (Fstrat) energy flux convergence events and examines the processes that drive Arctic anoma lous surface warming and sea ice loss during Ftrop events. …


Municipal Solutions To Climate Change ; A Case Study Of Stream Daylighting In Suffolk County, New York, Madison Hrysko Jan 2022

Municipal Solutions To Climate Change ; A Case Study Of Stream Daylighting In Suffolk County, New York, Madison Hrysko

Legacy Theses & Dissertations (2009 - 2024)

During the 1950’s and 1960’s Suffolk County, New York experienced rapid urbanization and development. To pave way for infrastructure, hydrological modifications were made to the land including the burial of naturally flowing streams. Daylighting streams is the nature-based process of bringing buried streams back to the surface. In turn, restoring ecosystem services, increasing local resilience to climate change impacts, and expanding biodiversity. Minimal research has been done using GIS technology alongside a set of criteria to select best fit streams for daylighting. This thesis aims to fill that gap by identifying best and second-best fit streams for daylighting in Suffolk …


Understanding Changes In Precipitation, Wildfires, And Possible Governing Factors Over Central Equatorial Africa, Yan Jiang Jan 2022

Understanding Changes In Precipitation, Wildfires, And Possible Governing Factors Over Central Equatorial Africa, Yan Jiang

Legacy Theses & Dissertations (2009 - 2024)

Tropical rainforests are global epicenters of biodiversity and modulators of climate. A long-term drying trend has occurred in the Congo Basin since the 1980s and this raises great concerns for sustaining the Congolese rainforest and local rain-fed agriculture. Motivated by documented rainfall changes and the need to improve understanding of main factors influencing precipitation variability and changes in Central Equatorial Africa (CEA), this dissertation conducts synthesized studies on 1) quantifying variations in precipitation seasonality by focusing on dry season duration, 2) estimating cascading wildfire risks associated with changes in precipitation patterns, and estimating impacts of 3) the tropical Indian Ocean …


The Contributions Of Dynamical And Diabatic Processes Preceding And Accompanying Major Greenland Ice-Melt Events, Scott Feldman Dec 2021

The Contributions Of Dynamical And Diabatic Processes Preceding And Accompanying Major Greenland Ice-Melt Events, Scott Feldman

Legacy Theses & Dissertations (2009 - 2024)

Extratropical cyclones and/or short-wave disturbances can reinforce Greenland blocking through upper-level flow amplification and can increase poleward heat and moisture transport into the Arctic. Increased poleward heat and moisture transport into the Arctic may enhance Greenland ice melt during the spring, summer, and fall months. The need to better understand the underlying dynamical and diabatic processes that may contribute to Greenland ice melt motivates this thesis. The purpose of this thesis is to investigate: 1) the role of advective warming due to poleward heat and moisture transport into the Arctic in facilitating Greenland ice melt, 2) the role of adiabatic …


Diagnosing High Sinuosity Regimes Associated With Anomalous Greenland Ice-Melt Events Using Self-Organizing Maps, Mansour El Riachy May 2021

Diagnosing High Sinuosity Regimes Associated With Anomalous Greenland Ice-Melt Events Using Self-Organizing Maps, Mansour El Riachy

Legacy Theses & Dissertations (2009 - 2024)

Sinuosity, a metric that describes the waviness of the circumpolar flow, is adapted to quantify modification of the tropospheric polar vortex within longitudinal sectors by localized incursions of warm, moist air from middle latitudes associated with Arctic cyclones (ACs). In this thesis, we identify four corridors of high AC track frequency, on which we center 90° longitudinal sectors comprising the following regions: Pacific, West of Greenland, Atlantic, and Asian. Sectorial sinuosity is calculated for the West of Greenland sector and is used to quantify the amplitude of the 300-hPa flow associated with anomalous Greenland ice-melt events.


Examining The Impact Of Synoptic-Scale Waves On Stratospheric Polar Vortex Variability From An Ensemble Forecast Perspective, Michael E. Main Jan 2020

Examining The Impact Of Synoptic-Scale Waves On Stratospheric Polar Vortex Variability From An Ensemble Forecast Perspective, Michael E. Main

Legacy Theses & Dissertations (2009 - 2024)

Major Sudden Stratospheric Warming (SSW) events are characterized by rapid warming of the polar regions at 10 hPa and are accompanied by a reversal of the 10-hPa zonal-mean zonal wind at 60˚N from westerly to easterly. Following an SSW event, stratospheric thermal and momentum anomalies can progress downward and linger near the tropopause for up to 60 days. These anomalies have major impacts on tropospheric sensible weather including increased likelihood of cold air outbreaks and heavy precipitation events. SSW events are largely forced by upward propagation of planetary-scale Rossby waves from the troposphere to the stratosphere. Synoptic-scale waves can contribute …


Improving Our Understanding Of The Relationship Between Ocean Heat Uptake And Climate Sensitivity, Michael Cameron Rencurrel Jan 2020

Improving Our Understanding Of The Relationship Between Ocean Heat Uptake And Climate Sensitivity, Michael Cameron Rencurrel

Legacy Theses & Dissertations (2009 - 2024)

One of the ultimate goals of the field of climate science is to determine exactly how sensitive the Earth is to anthropogenic forcing, with far reaching implications both from a scientific and policy standpoint. However, despite decades of observational and model analysis, large uncertainties in Earth's climate sensitivity persist. Recent advances have shown that climate feedbacks, the primary mechanism driving the sensitivity spread, are dependent on the spatial patterns of the surface response, intrinsically linked to how the ocean is working to uptake and transport energy across the globe. Given the importance of reducing the range of climate sensitivity from …


Dynamical Downscaling Of Near-Term Climate Variability And Change For The Main Hawaiian Islands Using Wrf, Katrina Marie Fandrich Jan 2020

Dynamical Downscaling Of Near-Term Climate Variability And Change For The Main Hawaiian Islands Using Wrf, Katrina Marie Fandrich

Legacy Theses & Dissertations (2009 - 2024)

As climate models continue to improve, the demand from resource managers and decision-makers for more accurate climate projections is increasing. However, natural climate variability poses a limit to the confidence in regional climate change projections, particularly for the mid-21st century. The unique geographic location of the Hawaiian Islands and its regional climate provide a challenging opportunity for climate modelers. The goal of this project is to examine both the Pacific Decadal Oscillation (PDO) and anthropogenic climate change for their impacts on near-term rainfall and temperature projections for the Hawaiian Islands. Of primary interest are the questions 1) is there a …


An Underground World : Creative Writing In The Dystopian Genre, Mary Kathleen Brown Jan 2019

An Underground World : Creative Writing In The Dystopian Genre, Mary Kathleen Brown

Legacy Theses & Dissertations (2009 - 2024)

Despite its importance for the creation of a compelling story, world-building is often overlooked in literary studies due to its complexity, with studies instead favoring analysis of plot, character, or situation. The dystopian genre dictates why world-building is a crucial element for fictional writing because it showcases a manipulated relationship between writer and reader. Using the overlap in possible worlds and actual worlds, this paper explores how world-building incites change in the actual world due to a reader correlating the possible world with their own. By way of example, my paper features the first three chapters of my dystopian novel, …


Detection And Attribution Of Wind Energy Changes In The Contiguous United States, North Atlantic Ocean And European Sector In The Twentieth Century, Shengzhe Chen Jan 2019

Detection And Attribution Of Wind Energy Changes In The Contiguous United States, North Atlantic Ocean And European Sector In The Twentieth Century, Shengzhe Chen

Legacy Theses & Dissertations (2009 - 2024)

Wind power is playing a greater role as an alternative energy resource to fossil fuels. The prediction skills for hourly and daily forecasts of hub-height (80 – 100 m) wind power are increasingly reliable. However, regarding historical trends in wind energy availability (an important variable for determining wind farm capacity factors), little is known about the interannual and decadal variability of the hub-height wind speed. With climate change uncertainty now incorporated into wind energy resource assessment, insight into the relative contribution from the internal variability of the climate system versus the external forcing is presently lacking. Here, Empirical Orthogonal Function …


The Simulated Impact Of Snow Cover And Soil Moisture On Convective Precipitation Within The Rocky Mountains Under Climate Warming, Brendan Charles Wallace Jan 2019

The Simulated Impact Of Snow Cover And Soil Moisture On Convective Precipitation Within The Rocky Mountains Under Climate Warming, Brendan Charles Wallace

Legacy Theses & Dissertations (2009 - 2024)

Warm season moist diurnal convection can be particularly sensitive to changes in land surface


Arctic Sea Ice Predictability And Prediction, Chao-Yuan Yang Jan 2019

Arctic Sea Ice Predictability And Prediction, Chao-Yuan Yang

Legacy Theses & Dissertations (2009 - 2024)

Arctic sea ice has experienced dramatic changes for the past few decades, which has profound global climatic effects, or feedbacks. The drastic changes and their associated impacts have led to increasing demand for sea ice predictions from a wide scope of stakeholders across seasonal to decadal timescales. Thus, it is important to improve our understanding of sea ice predictability on different timescales and our ability to predict Arctic sea ice.


Changes In Extreme Precipitation In The Northeast United States : 1979-2014, Macy Howarth Jan 2018

Changes In Extreme Precipitation In The Northeast United States : 1979-2014, Macy Howarth

Legacy Theses & Dissertations (2009 - 2024)

Extreme precipitation can have significant adverse impacts on infrastructure and property, human health, and local economies. This thesis examines recent changes in extreme precipitation in the Northeast United States, which here includes the states of Maine, New Hampshire, Vermont, New York, Massachusetts, Connecticut, Rhode Island, Pennsylvania, and New Jersey. Daily station data from 58 stations missing less than 5% of days for the years 1979–2014 from the United States Historical Climatology Network was used to analyze both total and extreme precipitation, with the latter defined as the top 1% of days with precipitation.


Projected Changes In Climate, Elevation-Dependent Warming, And Extreme Events Over Continental Ecuador For The Period 2041-2070, Oscar Chimborazo Jan 2018

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 …


Understanding The Relationship Between Winter Hawaii Precipitation And North Pacific Climate Variability For Past And Present Climate Conditions, Siyu Li Jan 2018

Understanding The Relationship Between Winter Hawaii Precipitation And North Pacific Climate Variability For Past And Present Climate Conditions, Siyu Li

Legacy Theses & Dissertations (2009 - 2024)

Kona lows (KLs) are a type of seasonal cut-off cyclones in the North Pacific around the Hawaiian Islands during the cold season month (Oct.-Apr.). KLs are important for the annual rainfall budget of the Hawaiian Islands. This study investigates what controls the winter precipitation variability over the Hawaiian Islands in the present-day climate and within a long-term paleoclimate simulation. ERA-interim data from 1979-2014 are used for the present-day analysis of the large-scale circulation. The potential vorticity is used as a measure of extratropical synoptic activity. The Hawaii Rainfall Index is from the Rainfall Atlas of Hawaii (seasonal means, 1920-2012). For …


Aerosol Direct Radiative And Cloud Adjustment Effects On Surface Climate Over The Eastern China : Analyses Of Wrf Model Simulations, Yangyang Song Jan 2018

Aerosol Direct Radiative And Cloud Adjustment Effects On Surface Climate Over The Eastern China : Analyses Of Wrf Model Simulations, Yangyang Song

Legacy Theses & Dissertations (2009 - 2024)

Aerosol climate effects consist of the initial forcing of atmospheric radiation perturbation through both the direct radiative effect and the modulation of radiatively-important cloud microphysics, and the subsequent changes in meteorology that also affect cloud macro- and micro-physics. The aerosol-induced cloud adjustment therefore involves many couplings and interactions, and its quantitative evaluation requires the use of model simulations. This study uses WRF model simulated changes in clouds and meteorology due to anthropogenic aerosol increases (versus 1970s) for 2002−2008 summers over the eastern China to address two relevant issues: direct radiative vs. cloud adjustment effects, and their roles in affecting surface …


Climate Change On The Quelccaya Ice Cap, Central Andes, And Its Relationship With The Large-Scale Circulation, Christian Pedro Yarleque Galvez Jan 2018

Climate Change On The Quelccaya Ice Cap, Central Andes, And Its Relationship With The Large-Scale Circulation, Christian Pedro Yarleque Galvez

Legacy Theses & Dissertations (2009 - 2024)

Glaciated areas over the central Andes are highly sensitive to atmospheric forcings, as demonstrated by their current accelerated retreat in response to global warming. The present Thesis is focused on quantifying and assessing future climate change impacts over Quelccaya ice cap (QIC), the world-largest tropical ice body, which is considered as a representative case of the tropical Andean cryosphere. I focused my study on characterizing large-scale forcing and future changes of precipitation and temperature, since they represent the most important variables for accumulation and ablation processes in glaciated mountain regions. In my research I developed tools to overcome the lack …


The Impact Snow Albedo Feedback Over Mountain Regions As Examined Through High-Resolution Regional Climate Change Experiments Over The Rocky Mountains, Theodore Letcher Jan 2017

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 …


Kz Spatial Wave Separation With Applications To Atmospheric Data, Ming Luo Jan 2017

Kz Spatial Wave Separation With Applications To Atmospheric Data, Ming Luo

Legacy Theses & Dissertations (2009 - 2024)

Unlike one-dimensional wave reconstruction, reconstruction 2D spatial wave via Fourier Transform doesn’t look like a non-parametric algorithm. In other words, we need the wave frequency and wave direction information to recover the spatial wave via Fourier Transform, especially when the stress of noise is present. The direct consequence is that accurate estimations of wave parameters are need for reconstructing of spatial waves. To this end, we propose to improve the accuracy of motion image scale detection and parameter estimations with optimization based on Kolmogorov-Zurbenko periodogram (KZP) information. Related methods and algorithms are denoted under the name of Kolmogorov-Zurbenko wave separations. …


Understanding Predictive Skill Of Arctic Sea Ice And Its Linkage With Mid-Latitude Weather And Climate In The Ncep Climate Forecast System, Colleen Mchugh Jan 2017

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 …


Climate Change, Spruce Root Phenology, And Allocation Of Carbon Below- And Above-Ground, Marie Louise Orton Jan 2017

Climate Change, Spruce Root Phenology, And Allocation Of Carbon Below- And Above-Ground, Marie Louise Orton

Legacy Theses & Dissertations (2009 - 2024)

Tree ring analysis has relied on a close relationship between climate and photosynthetically-derived stem enlargement. Lengthening growing seasons associated with climate warming have been predicted to enhance carbon sequestration as wood in trees, but this


State Dependency Of The Forest-Tundra-Short Wave Feedback : Comparing The Mid-Pliocene And Pre-Industrial Eras Using A Newly-Developed Vegetation Model, Pablo Paiewonsky Jan 2017

State Dependency Of The Forest-Tundra-Short Wave Feedback : Comparing The Mid-Pliocene And Pre-Industrial Eras Using A Newly-Developed Vegetation Model, Pablo Paiewonsky

Legacy Theses & Dissertations (2009 - 2024)

The forest-tundra-short wave feedback is the dominant short wave (SW) vegetation feedback at mid-to-high northern latitudes and is an important feedback in Earth’s climate system, especially due to its potential role in modulating glacial cycles. Little research has been done on how the strength of this feedback might vary with the background climate state. It is hypothesized that the feedback has generally strengthened over the last four million years. The feedback mechanism is hypothesized to be weaker under warm Northern Hemispheric conditions when tundra is primarily confined to the high Arctic than under cooler conditions in which the forest-tundra boundary …


Understanding Climatic Adjustments To Variations In Tropical Ocean Heat Transport, Michael Cameron Rencurrel Jan 2017

Understanding Climatic Adjustments To Variations In Tropical Ocean Heat Transport, Michael Cameron Rencurrel

Legacy Theses & Dissertations (2009 - 2024)

One of the outstanding problems within the climate community has been how to reconcile the geological proxy records of past warm, equable climates, characterized by both an increase in the global mean surface temperature and a decrease in the equator-to-pole temperature gradient, with numerical simulations of the same period. Recent work has shown that tectonic driven changes in the meridional ocean heat transport (OHT) may have played a signicant role in the warming. Here, we study the adjustment of the climate to variations in OHT using a suite of slab-ocean aquaplanet GCM simulations spanning 24 different imposed variations in OHT …


Impacts Of Internal Variability On Climate Trends In Large Ensemble Simulations By Two Climate Models, Christine Bloecker Jan 2017

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. …


Influence Of Volcanic Eruptions On Tropical Hydroclimate During The Last Millennium, Christopher Colose Jan 2017

Influence Of Volcanic Eruptions On Tropical Hydroclimate During The Last Millennium, Christopher Colose

Legacy Theses & Dissertations (2009 - 2024)

Volcanic eruptions exert the most important radiative forcing on Earth’s climate during the pre-industrial interval of the last millennium. In this thesis, I investigate the role of volcanic eruptions in altering tropical climate, including temperature and rainfall. I primarily use forced transient simulations of the last millennium as a tool to explore how explosive volcanic events project onto the hydrologic cycle, as well as the imprint of water isotopologues (H216O, H218O) associated with rainfall. Attention is given to the South American continent specifically (in chapter 2), and to the entire tropics (in chapter 3).


Climate Fingerprints Of The Interdecadal Pacific Oscillation, Bo Dong Jan 2017

Climate Fingerprints Of The Interdecadal Pacific Oscillation, Bo Dong

Legacy Theses & Dissertations (2009 - 2024)

The Interdecadal Pacific Oscillation (IPO) is a multi-decadal quasi-oscillation seen primarily in tropical and extratropical Pacific sea surface temperatures (SSTs). Interacting with the atmosphere, the IPO has been shown to affect global and regional climate. However, a quantitative global synthesis of the IPO’s climate fingerprints and the underlying mechanisms are still lacking. Based on observational and reanalysis data and atmospheric model simulations, this dissertation investigates the IPO’s influence on regional climates over the globe, and its interactions with El Niño-Southern Oscillation (ENSO) and global warming.


Understanding The Dependence Of Radiative Feedbacks And Clouds On The Spatial Structure Of Ocean Heat Uptake, Lance Rayborn Jan 2016

Understanding The Dependence Of Radiative Feedbacks And Clouds On The Spatial Structure Of Ocean Heat Uptake, Lance Rayborn

Legacy Theses & Dissertations (2009 - 2024)

Ocean heat uptake and radiative forcing are important for understanding transient climate change. Differences in efficacy of ocean heat uptake (suppression of surface warming per unit energy flux into the deep oceans relative to CO2 forcing) account for a substantial fraction of the spread in transient warming between models. Rose et al. (2014) studied the dependence of efficacy on the spatial pattern of ocean heat uptake in an ensemble of aquaplanet simulations with prescribed ocean heat uptake, and found large differences in model responses to high versus low latitude uptake. This study accurately quantifies these model responses through the use …


Hydroclimate Changes In The South-Central Great Plains Of The United States : A Synoptic Approach, Pawel Slaski Jan 2016

Hydroclimate Changes In The South-Central Great Plains Of The United States : A Synoptic Approach, Pawel Slaski

Legacy Theses & Dissertations (2009 - 2024)

Hydroclimate changes over the Southern Central Great Plains (SCGP) of the United States have been occurring throughout the last century. These changes have had a major impact on the local ecosystems, agriculture, and human society in the region by, e.g., producing a higher frequency of drought over the last century. Climate models project further increases of drought in the 21st century over this region under increasing greenhouse gases. This study analyzes climate model simulations to examine changes in synoptic conditions associated with the projected drought increases over the SCGP. Synoptically, mesoscale convective complexes (MCCs) produce a large portion of the …