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 …

S6e9: What Does Maine Need To Expand Electric Vehicle Use?, Ron Lisnet, Jonathan Rubin

The Maine Question

Reducing greenhouse gas emissions in Maine will require a broader adoption of electric vehicles, according to University of Maine economist Jonathan Rubin. Officials from the Maine Department of Transportation and other state agencies have a role to play in fueling the transition away from gas-powered cars and trucks. To guide them, Rubin, professor of economics and director of the Margaret Chase Smith Policy Center, and his colleagues from the National Cooperative Highway Research Program (NCHRP) released a report that outlines strategies for reducing emissions from the transportation sector.

On this week’s episode of “The Maine Question,” Rubin discusses the report …

S6e1: What Happens If Mount Everest Loses All Of Its Snow And Ice?, Ron Lisnet, Paul A. Mayewski

The Maine Question

No place on earth can escape the effects of climate change, not even Mount Everest. The highest glacier on the world’s tallest mountain — the South Col Glacier — is rapidly disappearing. A new University of Maine-led study found that the glacier is losing several decades of ice and snow accumulation annually due to human-induced climate change.

These findings are the latest from the 2019 National Geographic and Rolex Perpetual Planet Everest Expedition, led by UMaine Climate Change Institute director Paul Mayewski. In this episode of “The Maine Question,” Mayewski and UMaine Ph.D. candidate Mariusz Potocki, both co-authors of the …

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 …

Tb202: Composition And Biomass Of Forest Floor Vegetation In Experimentally Acidified Paired Watersheds At The Bear Brook Watershed In Maine, Peter Kenlan, G. B. Wiersma, A. S. White, I. J. Fernandez

Technical Bulletins

The percentage cover (abundance), frequency of occurrence, biomass, species richness, and species diversity of understory herbs was measured on a paired watershed ecosystem in eastern Maine, USA. This paired watershed site (Bear Brook Watershed in Maine, BBWM) has had the West Bear Brook Watershed treated bi-monthly with granular ammonium sulfate at a rate of 28.8 kg S ha-1 yr-1 and 25.2 kg N ha-1 yr-1 since 1989. East Bear Brook Watershed serves as the reference site. More than 100 plots were randomly located across the two watersheds. The data suggest that there is generally a lower frequency of occurrence of …

(Rcn) Terrestrial Ecosystem Response To Atmospheric And Climatic Change, Lindsey E. Rustad

University of Maine Office of Research Administration: Grant Reports

Future changes in the global carbon balance and associated feedbacks to climate will depend on ecosystem responses to multiple, interacting drivers of global change, such as elevated CO2, temperature, N deposition and changes in the amount and timing of precipitation. Efforts to predict these interactions with modeling approaches have been limited by a lack of relevant experimental data, as well as the absence of mechanisms for rapid communication between modelers and experimentalists. This grant will establish a network of global change scientists in an initiative on Terrestrial Ecosystem Responses to Atmospheric and Climatic Change (TERACC), with the aim to (1) …

Tb196: Temperature, Soil Moisture, And Streamflow At The Bear Brook Watershed In Maine (Bbwm), Ivan J. Fernandez, Joseph E. Karem, Stephen A. Norton, Lindsey E. Rustad

Technical Bulletins

The Bear Brook Watershed in Maine is a whole-ecosystem chemical manipulation initiated in 1987 to study the effects of acid deposition on forests and surface waters. The focus of this research was to understand the biogeochemical response of watersheds with emphasis on chemistry and hydrology. In 2001 a program was initiated to provide more detailed measurements of temperature and moisture to examine critical linkages amongst chemical, biological, and physical processes that ultimately work together to define ecosystem function. The purpose of this publication is to provide data from the initial phase of soil temperature, air temperature, and soil moisture measurements …

Highly Detailed Reconstructions Of New England Weather Over The Past Few Centuries And Their Climatic Implications, Gregory A. Zielinski

University of Maine Office of Research Administration: Grant Reports

This award will enable researchers to reconstruct daily weather conditions for New England over the past 300 years by compiling and analyzing written archives such as diaries, journals, agricultural records, and marine logs. These archives will be used to reconstruct daily weather maps that will be compared with recent climatic conditions. New England has a large number of lengthy weather archives and is a region sensitive to changing climatic conditions. The region is influenced by storm tracks and upper-air disturbances that impact the Canadian High, Icelandic Low and the Bermuda-Azores High from year-to-year.

Obtaining highly detailed and lengthy records of …

Snow Chemistry Across Antarctica, Nancy Bertler, Paul Andrew Mayewski, Alberto Aristarain, P. Barrett, S. Becagli, Ronaldo Torma Bernardo, Xiao Cunde, M. Curran, Qin Dahe, Daniel Dixon, Francisco Adolfo Ferron, H. Fischer, Markus Frey, M. Frezzotti, F. Fundel, Christophe Genthon, R. Gragani, Gordon Hamilton, M. Handley, Sungmin Hong, E. Isaksson, Ren Jiawen, Kokichi Kamiyama, Satoru Kanamori, Eija Karkas, L. Karlöf, S. Kaspari, K. Kreutz, A. Kurbatov, E. Meyerson, Hideaki Motoyama, R. Mulvaney, Zhang Mingjun, H. Oerter, E. Osterberg, M. Proposito, A. Pyne, U. Ruth, Jefferson Cardia Simoes, B. Smith, S. Sneed, Kimmo Teinila, F. Traufetter, R. Udisti, Aki Virkkula, Okitsugu Watanabe, B. Williamson, E. Wolff, Li Zhongqin

Earth Science Faculty Scholarship

An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO₃, SO₄) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, the United Kingdom, the United States and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve …

El Niño Suppresses Antarctic Warming, Nancy A. N. Bertler, Peter J. Barrett, Paul Andrew Mayewski, Ryan L. Fogt, Karl J. Kreutz, James Shulmeister

Earth Science Faculty Scholarship

Here we present new isotope records derived from snow samples from the McMurdo Dry Valleys, Antarctica and re-analysis data of the European Centre for Medium-Range Weather Forecasts (ERA-40) to explain the connection between the warming of the Pacific sector of the Southern Ocean [Jacka and Budd, 1998; Jacobs et al., 2002] and the current cooling of the terrestrial Ross Sea region [Doran et al., 2002a]. Our analysis confirms previous findings that the warming is linked to the El Niño Southern Oscillation (ENSO) [Kwok and Comiso, 2002a, 2002b; Carleton, 2003; Ribera and Mann …

Variability In Accumulation Rates From Gpr Profiling On The West Antarctic Plateau, Vandy B. Spikes, Gordon S. Hamilton, Steven A. Arcone, Susan Kaspari, Paul Andrew Mayewski

Earth Science Faculty Scholarship

Isochronal layers in firn detected with ground-penetrating radar (GPR) and dated using results from ice-core analyses are used to calculate accumulation rates along a 100 km across-flow profile in West Antarctica. Accumulation rates are shown to be highly variable over short distances. Elevation measurements from global positioning system surveys show that accumulation rates derived from shallow horizons correlate well with surface undulations, which implies that wind redistribution of snow is the leading cause of this variability. Temporal changes in accumulation rate over 25-185 year intervals are smoothed to along-track length scales comparable to surface undulations in order to identify trends …

Antarctic Oversnow Traverse-Based Southern Hemisphere Climate Reconstruction, Paul Andrew Mayewski

Earth Science Faculty Scholarship

On 2 January 2003, the U.S. component of the International Trans Antarctic Scientific Expedition (U.S. ITASE) (Figure 1) arrived at the South Pole after completing more than 5000 km of oversnow traverses that included much of west Antarctica and a portion of east Antarctica (Figure 2). During the traverses, which were performed from 1999 through 2003, U.S. ITASE focused on collecting data that will allow the reconstruction of sub-annual scale climate variability and changes in the chemistry of the atmosphere over the last 200+ years.

ITASE is a multi-disciplinary research program supported by 19 nations and endorsed by the Scientific …

Chemical Composition Of Fresh Snow On Xixabangma Peak, Central Himalaya, During The Summer Monsoon Season, Shichang Kang, Dahe Qin, Paul Andrew Mayewski, Sharon B. Sneed

Earth Science Faculty Scholarship

The physical and chemical analysis of ice cores recovered from glaciers in the Himalaya provide some of the best records of past climate change in the region (e.g. Qin and others, 2000; Thompson and others, 2000; Kang and others, 2001, 2002). In order to better understand the climatic and environmental records preserved in snow and ice, studies have investigated the precipitation chemistry in the high Himalaya, notably that the northern slopes of the central Himalaya (Mayewski and others, 1986; Jenkins and others 1987) and the southern slopes of the central Himalaya (Shrestha and others, 1997; Marinoni and others, 2001).

High-Precision Dating Of Volcanic Events (A.D. 1301–1995) Using Ice Cores From Law Dome, Antarctica, Anne S. Palmer, Tas D. Van Ommen, Mark A. J. Curran, Vin Morgan, Joe M. Souney, Paul Andrew Mayewski

Earth Science Faculty Scholarship

A record of volcanic activity over the period A.D. 1301–1995 has been extracted from three Law Dome ice cores (East Antarctica). The record dating is unambiguous at the annual level from A.D. 1807 to 1995 and has an uncertainty of ±1 year at A.D. 1301. Signals from 20 eruptions are preserved in the record, including those of two unknown eruptions with acid deposition beginning in A.D. 1810.8 and A.D. 1685.8. The beginning of the ice core signal from the A.D. 1815 Tambora eruption is observed in the austral summer of A.D. 1816/1817. The mean observed stratospheric transport and deposition time …

The Dynamics And Significance Of Carbon Monoxide Exchanges Between Wetlands And The Atmosphere, Gary M. King

University of Maine Office of Research Administration: Grant Reports

Carbon monoxide (CO) plays a major role in atmospheric chemistry. Through a series of reactions, CO can contribute to the formation of tropospheric ozone, which poses a serious health concern on a regional scale. While anthropogenic sources of CO are reasonably well understood, relatively little is known about natural CO sources and sinks. Wetlands have been discounted as CO sources on the basis of sediment CO concentrations. However, plant leaves and stems produce significant amounts of CO when illuminated by the sun. Because of their large amounts of plant biomass, wetlands are likely strong net CO sources. Our work will …

Workshop: A Cross-Biome Synthesis Of Ecosystem Response To Global Warming; October 1998 In Santa Barbara, Ca, Ivan J. Fernandez, Lindsey Rustad

University of Maine Office of Research Administration: Grant Reports

Greenhouse gas emissions are expected to increase mean global temperature by 3-5 C in the next 50-100 years. The consequences of this warming for primary ecosystem processes are not yet understood, and have become tile focus of an emergent field of ecological research. This project will bring together a multi-disciplinary, international group of scientists representing 22 soil/air warming sites from seven countries to synthesize the current knowledge on the effects of elevated temperature on terrestrial ecosystems. In addition, the participants will use this forum to discuss and launch a new GCTE Ecosystem Warming Consortium, which will have far reaching effects …

Monsoon And Dust Signals Recorded In Dasuopu Glacier, Tibetan Plateau, Kang Shichang, Cameron P. Wake, Qin Dahe, Paul Andrew Mayewski, Yao Tandong

Earth Science Faculty Scholarship

During summer 1997, a 15m firn core was recovered from Dasuopu glacier (28°23'N, 85° 44' E; 7000 m a.s.l.) on the northwest margin of Xixabangma Feng in the central Himalaya. Oxygen isotope values and concentrations of Ca²⁺, Mg²⁺, NH₄⁺, SO₄^2- and NO₃^- were measured over the 10 years of snow accumulation captured in the firn core. The seasonal variations of δ¹⁸O values and major-ion concentrations in the Dasuopu core indicated that summer monsoon and dust signals are clearly recorded in Dasuopu glacier. Annual variations in the δ …

Antarctic's Role Pursued In Global Climate Change, Paul Andrew Mayewski, I. Goodwin

Earth Science Faculty Scholarship

The impact of Antarctica on global climate change and the impact of global climate change on Antarctica are the focal points of a current series of expeditions there, and an international, interdisciplinary array of researchers met this past spring to go over the expeditions' progress. Advances were reported in describing the impact of the seasonal cycle, semiannual oscillation, and the El Niño-Southern Oscillation (ENSO) cycle on Antarctic accumulation in recent decades.

Difficulties still remain, however, in explaining fully the history and forcing of the Antarctic climate and the links between tropical forcing and high-latitude response. The difficulties arise largely because …

Spatial Variability Of Climate And Past Atmospheric Circulation Patterns From Central West Antarctic Glaciochemistry, David B. Reusch, Paul Andrew Mayewski, Sallie I. Whitlow, Iqbal I. Pittalawa, Mark S. Twickler

Earth Science Faculty Scholarship

Atmospheric circulation patterns and the spatial variability of atmospheric chemistry and moisture transport in central West Antarctica are investigated using new 40 year long (1954–1994 A.D.) glaciochemical and accumulation rate records developed from four firn cores from this region. The core sites lie on a 200 km traverse from 82° 22′ S, 119° 17′ W to 81° 22′ S, 107° 17′ W. The glaciochemical records represent the major ionic species present in Antarctic snow: Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl⁻, NO₃⁻, and SO₄²⁻. High spatial …

Climatological Significance Of Δ18O In Precipitation And Ice Cores: A Case Study At The Head Of The Ürütnqi River, Tien Shan, China, Hou Shugui, Qin Dahe, Paul Andrew Mayewski, Yang Qinzhao, Ren Jiawen, Li Zhongqin, Xiao Cunde

Earth Science Faculty Scholarship

Stable-oxygen-isotope ratios (δ¹⁸O) collected from the headwaters of the Ürümqi river, Tien Shan, China, were used to test the relationship between δ¹⁸O temporal relationship is found between δ¹⁸O monthly averages which remove synoptic-scale influences such as changes in condensation level, condensation temperature and moisture sources (Yao and others, 1996). Linear fits as high as 0.95‰°C^-1 for precipitation events and 1.23‰°C^-1 for monthly averages are found. Although the δ¹⁸O (∼2 km from the precipitation sampling site) decreased dramatically compared to the precipitation samples , the ice-core records of annually averaged δ …

Soluble Species In Aerosol And Snow And Their Relationship At Glacier 1, Tien Shan, China, Junying Sun, Dahe Qin, Paul Andrew Mayewski, Jack E. Dibb, Sallie Whitlow, Zhongqin Li, Qinzhao Yang

Earth Science Faculty Scholarship

Simultaneous sampling of aerosol (n = 20) and snow (n = 114) was made at Glacier 1, Tien Shan, between May 19 and June 29, 1996. Similar temporal patterns of some major ion (calcium, magnesium, potassium, sodium, chloride, and sulfate) concentrations between snow and aerosol show that snow chemistry basically reflects changes in the chemistry of the atmosphere. This gives us confidence in the reconstruction of past atmospheric change using some snow data. There are no significant correlations between aerosol and snow samples for ammonium and nitrate. This suggests that postdepositional and/or postcollection processes may alter ammonium and …

Limited Migration Of Soluble Ionic Species In A Siple Dome, Antarctica, Ice Core, Karl J. Kreutz, Paul Andrew Mayewski, Sallie I. Whitlow, Mark S. Twickler

Earth Science Faculty Scholarship

High-resolution (>10 samples a ^-1) glaciochemical analyses covering the last 110 years from a Siple Dome, Antarctica, ice core reveal limited migration of certain soluble ionic species (methane sulfonic acid, NO₃ and Mg²⁺). Th e observed chemical migration m ay be due in part to seasonal alternation between less acidic winter (from high sea-salt concentrations) and m ore acidic summer (from high marine biogenic acid concentrations) layers, common at coastal sites such as Siple Dome. Exact mechanisms to explain the migration are unclear, although simple diffusion and gravitational movement are unlikely since new peaks are …

Spatial Variability Of Snow Chemistry In Western Dronning Maud Land, Antarctica, Malin Stenberg, Elisabeth Isaksson, Margareta Hansson, Wibjörn Karlén, Paul Andrew Mayewski, Mark S. Twickler, Sallie I. Whitlow, Niels Gundestrup

Earth Science Faculty Scholarship

During the austral summer of 1993-94 a number of 1-2 m deep snow pits were sampled in connection with firn-coring in western Dronning Maud Land, Antarctica. The traverse went from 800 to about 3000 m a.s.l. upon the high-altitude plateau. Profiles of cations (Na⁺, K⁺, Mg²⁺, Ca²⁺), anions (CI^-, NO^3-, SO₄^2-, CH₃SO₃^-) and stable oxygen isotopes (δ¹⁸O) from II snow pits are presented here. Close to the coast 2 m of snow accumulates in about 2-3 years, whilst …

Assessment Of The Record Of The 1982 El Chichón Eruption As Preserved In Greenland Snow, Gregory A. Zielinski, Jack E. Dibb, Qinzhao Yang, Paul Andrew Mayewski, Sallie Whitlow, Mark S. Twickler, Mark S. Germani

Earth Science Faculty Scholarship

Variability in the SO 4 2 - and Cl⁻ time series for the 1980s from 12 shallow snow pits across the Greenland ice sheet is used to evaluate the record of the 1982 El Chichón eruption and the potential for recording a moderate northern equatorial eruption in a single Greenland ice core. Composition of volcanic glass found in spring 1983 snow in one of the pits in the Summit region matches that from El Chichón glass, thereby verifying the deposition of material from the eruption. High Na⁺ and Cl⁻ concentrations in this same layer probably represent deposition …

A 110,000-Year History Of Change In Continental Biogenic Emissions And Related Atmospheric Circulation Inferred From The Greenland Ice Sheet Project Ice Core, L. D. Meeker, Paul Andrew Mayewski, M. S. Twickler, S. I. Whitlow, D. Meese

Earth Science Faculty Scholarship

The 110,000-year record of ammonium concentrations from the Greenland Ice Sheet Project 2 (GISP2) ice core provides the basis for an analysis of terrestrial biological production and atmospheric circulation patterns involved in the transport of biologically produced ammonium to the Greenland atmosphere. The directly measured concentration series was selected for analysis, rather than that of estimated ammonium flux, after a detailed analysis of the relationship among ice core glaciochemical concentrations and a high-resolution simultaneous record of snow accumulation from the GISP2 core. Analysis of the ammonium concentration series shows that maxima in background levels of ammonium in the Greenland atmosphere …