Atmospheric Sciences Commons^™

Glaciochemical Investigations In Three Southern Hemisphere Mountain Sites, Mariusz Potocki

Electronic Theses and Dissertations

The research presented in this dissertation focuses on glaciochemical records of trace elements, major ions, and stable water isotopes from three mountain regions: the Antarctic Peninsula, the Central Chilean Andes, and South Georgia Island.

The first section reports a significant increase in U concentration over 27 years on Detroit Plateau, Antarctic Peninsula. U concentrations in the ice core increase by as much as 102 between the 1980s and 2000s, accompanied by increased variability in recent years. The U concentration increase coincides with expanded open pit mining in the Southern Hemisphere, most notably Australia. Since other land-source dust elements do not …

Variations In The Southern Hemisphere Westerlies Over The Last 23,000 Years From Lake Records In The Falkland Islands, Meghan M. Spoth

Electronic Theses and Dissertations

The Southern Hemisphere Westerlies (SHW) are an important driver of climate in the mid-latitudes of the Southern Hemisphere. Abrupt latitudinal migration of this coupled atmospheric-oceanic system is thought to be linked to the onset of the Termination at the end of the last ice age and to subsequent climatic variation through the late-glacial period and Holocene. However, the timing and spatial extent of these shifts, as well as variations in wind intensity, are poorly constrained, hindering our understanding of abrupt climate change in the Southern Hemisphere. In addition, future changes in the position and intensity of the SHW are a …

Extratropical Cyclones And Associated Climate Impacts In The Northeastern United States, Julia Simonson

Electronic Theses and Dissertations

There is growing concern that some aspects of severe weather could become more frequent and extreme across the northeastern United States (USNE) as a consequence of climate change. Extratropical cyclones and frontal systems are a common factor in a variety of severe weather hazards in the region. This dissertation examines three types of meteorological events impacting the USNE – ice storms, heavy rainfall, and high-wind events. The first research topic utilizes the Weather Research and Forecasting (WRF) model in a case study of the December 2013 New England ice storm. In this analysis, a series of tests are conducted to …

Mechanisms Of Ice Core Stable Isotope Variability In The Upper Kaskawulsh-Donjek Region, St. Elias Mountains, Yukon, Canada, Erin A. Mcconnell

Electronic Theses and Dissertations

I use instrumental and ice core records to examine drivers of observed isotope variability in the Upper Kaskawulsh-Donjek (UKD) region of the St. Elias Mountains, Yukon, Canada over the time frame of instrument-proxy overlap (mid-1900s to present). One of the drivers of post-depositional isotope signal alteration is the vertical percolation of meltwater from the glacier surface through shallow layers of snow, which causes a reduction in the amplitude of the isotope signal recorded in ice cores. I examine isotope signal preservation in two sites in the St. Elias Mountains: Eclipse Icefield and Icefield Divide. These sites are relatively close (~30 …

Past, Present, And Future Arctic Climate And National/Community Risk Assessment, Jeff Auger

Electronic Theses and Dissertations

The Arctic is warming at a rate nearly double that of the global average. The enhanced rate of warming impacts weather and climate across the Northern Hemisphere. As the meridional (south to north) thermal gradient weakens, the middle-latitude westerlies are expected to slow and become “wavier” increasing heat and moisture advection to higher latitudes. A quasi-stationary ridge-trough system of the jet stream increases chances for droughts, floods, heatwaves, and cold spells. These impacts have already been observed as North American forest fires and early or extended Great Lake ice out. It is more important than ever to understand how the …

A Comparison Of Global Climate Reanalysis And Climate Of South Greenland And The North Atlantic, Jeff Auger

Electronic Theses and Dissertations

Global climate reanalysis models are regularly used in many scientific fields concerning climate and atmospheric observation. This thesis utilizes reanalysis models in two chapters in order to gain insight into North Atlantic climate teleconnections and their relation to precipitation across South Greenland. This first chapter of this thesis compares the four most recent reanalysis models – ECMWF Reanalysis Interim (ERA-I), NCEP Climate Forecast System Reanalysis (CFSR), JMA 55-year Reanalysis (JRA-55), and NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) – and develops from these models a monthly-mean ensemble average of common meteorological variables for the period 1979-2013. Results from …

Event Discovery And Classification In Space-Time Series: A Case Study For Storms, Avinash Rude

Electronic Theses and Dissertations

Recent advancement in sensor technology has enabled the deployment of wireless sensors for surveillance and monitoring of phenomenon in diverse domains such as environment and health. Data generated by these sensors are typically high-dimensional and therefore difficult to analyze and comprehend. Additionally, high level phenomenon that humans commonly recognize, such as storms, fire, traffic jams are often complex and multivariate which individual univariate sensors are incapable of detecting. This thesis describes the Event Oriented approach, which addresses these challenges by providing a way to reduce dimensionality of space-time series and a way to integrate multivariate data over space and/or time …