Oceanography and Atmospheric Sciences and Meteorology Commons^™

Observations Of Peroxyacetyl Nitrate (Pan) In The Upper Troposphere By The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (Ace-Fts), K. A. Tereszchuk, D. P. Moore, J. J. Harrison, C. D. Boone, M. Park, J. J. Remedios, W. J. Randel, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

Peroxyacetyl nitrate (CH₃CO·O₂NO₂, abbreviated as PAN) is a trace molecular species present in the troposphere and lower stratosphere due primarily to pollution from fuel combustion and the pyrogenic outflows from biomass burning. In the lower troposphere, PAN has a relatively short lifetime and is principally destroyed within a few hours through thermolysis, but it can act as a reservoir and carrier of NO_x in the colder temperatures of the upper troposphere, where UV photolysis becomes the dominant loss mechanism. Pyroconvective updrafts from large biomass burning events can inject PAN into the upper troposphere …

Rose: Roadmaps Towards Sustainable Energy Futures And Climate Protection: A Synthesis Of Results From The Rose Project, Elmar Kriegler, Ioanna Mouratiadou, Gunnar Luderer, Nico Bauer, Katherine Calvin, Enrica Decian, Robert J. Brecha, Wenying Chen, Aleh Cherp, Jae Edmonds, Kejun Jiang, Shonali Pachauri, Fabio Sferra, Massimo Tavoni, Ottmar Edenhofer

Physics Faculty Publications

EXECUTIVE SUMMARY

Exploring energy demand and supply uncertainty: An exploration of uncertainty on drivers of energy demand and supply is indispensable for better understanding the prospects of long-tern climate stabilization. The RoSE study is the first of its kind to systematically explore the impact of economic growth, population and fossil fuel scarcity, in scenarios with and without climate policy, using a model ensemble. A feature of RoSE is the participation of five established integrated assessment modelling teams from three important regions in international climate policy negotiations: the EU, the USA and China.

Economic growth: Neither slow nor rapid economic growth …

Isotopic (Δ13c, Δ14c) Analysis Of Organic Acids In Marine Samples Using Wet Chemical Oxidation, Susan Q. Lang, G. L. Früh-Green, S. M. Bernasconi, L. Wacker

Faculty Publications

We present a method for the isolation and off-line isotope analysis of formate and acetate in marine samples. Organic acids are separated by high performance liquid chromatography and collected in glass Exetainer® screw-capped vials that have been prespiked with an oxidant and flushed with helium. The vials are subsequently heated to convert the organic compounds to CO₂ for radiocarbon and δ¹³C analysis. Small aliquots are sampled for measurement of δ¹³C by isotope ratio mass spectrometry, whereas the majority of the CO₂ is saved for radiocarbon analysis by accelerator mass spectrometry using a gas ion …

Extreme Wave Events In Ireland: 14 680 Bp–2012, Laura Cooke, John M. Dudley, Frédéric Dias

Articles

The island of Ireland is battered by waves from all sides, most ferociously on the west coast as the first port of call for waves travelling across the Atlantic Ocean. However, when discussing ocean events relevant to the nation of Ire- land, one must actually consider its significantly larger designated continental shelf, which is one of the largest seabed territories in Europe. With this expanded definition, it is not surprising that Ireland has been subject to many oceanic events which could be designated as “extreme”; in this paper we present what we believe to be the first catalogue of such …

Conservation Mooring Study, Urban Harbors Institute, University Of Massachusetts Boston

Urban Harbors Institute Publications

Most boaters who moor their vessels in Massachusetts waters have traditionally employed free swinging moorings that use heavy bottom chain. In important sensitive habitats such as eelgrass beds, these types of moorings often have negative impacts on the benthic habitat – from the circular movement of the chain around the anchor point, and/or from the anchor itself.

This document objectively describes the different characteristics of conventional moorings versus conservation moorings designed to minimize disruption to the benthic habitat. This report includes discussions on the following topics:

• Technologies available
• Ecological impacts
• Functional differences
• Economical differences
• Regulatory issues

These comparisons, along with …

Rock Glaciers In The Eastern Cascades, Washington, Mark Weidenaar

Undergraduate Honors Theses

The eastern portion of Washington State's Cascade Range is a place not previously examined for rock glaciers, due to proximity to the Pacific Ocean and its associated marine-influenced climate. The objectives of this study were to determine spatial, activity, and genesis patterns, and paleoclimatic implications of Eastern Cascade rock glaciers. Using Google Earth, I found 103 rock glaciers in the study area. Rock glaciers are more common further east of the Cascade crest and more north in latitude, with the largest concentrations occurring east of Lake Chelan (22) and in the Pasayten Wilderness (28) in the North Cascades. None were …

Radio Signals From Electron Beams In Terrestrial Gamma Ray Flashes, Valerie Connaughton, Joseph R. Dwyer, Eric Cramer

Aerospace, Physics, and Space Science Faculty Publications

We show that the rate of association between terrestrial gamma ray flashes (TGFs) observed by the Fermi gamma ray burst monitor and VLF discharges detected by the World Wide Lightning Location Network (WWLLN) depends strongly on the duration of the TGF, with the shortest TGFs having associated WWLLN events over 50% of the time, and the longest TGFs showing a less than 10% match rate. This correlation is stronger if one excludes the WWLLN discharges that are not simultaneous (within 200 ms) with the TGF. We infer that the simultaneous VLF discharges are from the relativistic electron avalanches that are …

The Angular Distribution Of Energetic Electron And X-Ray Emissions From Triggered Lightning Leaders, M. M. Schaal, Joseph R. Dwyer, Hamid K. Rassoul, Jonathan David Hill, Douglas M. Jordan, Martin A. Uman

Aerospace, Physics, and Space Science Faculty Publications

We investigate individual X-ray bursts from lightning leaders to determine if energetic electrons at the source (and hence X-rays) are emitted isotropically or with some degree of anisotropy. This study was motivated by the work of Saleh et al. (2009), which found the falloff of X-rays in concentric radial annuli, covering all azimuthal directions in each annulus, from the lightning channel to be most consistent with an isotropic electron source. Here we perform a statistical analysis of angular and spatial distributions of X-rays measured by up to 21 NaI/PMT detectors at the International Center for Lightning Research and Testing site …

Analysis Of The Experiment On Registration Of X-Rays From The Stepped Leader Of A Cloud-To-Ground Lightning Discharge, Leonid P. Babich, Igor M. Kutsyk, Evgeni N. Donsko, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

Using a Monte Carlo technique to simulate the transport of runaway electrons (REs) and X-rays in the atmosphere and through attenuators covering detectors, we have modeled the results of experiments to detect X-rays from triggered lightning and stepped leaders of a natural cloud-to-ground lightning. In the model, bremsstrahlung of high-energy runaway electrons (REs) generated at the leader front is assumed to be the origin of X-rays. Specific fluxes (per one RE) of photons and bremsstrahlung energy at the detectors were calculated. The analysis was executed with monoenergetic and exponential initial energy distributions of REs with different angular distributions. To reproduce …

Modeling Terrestrial Gamma Ray Flashes Produced By Relativistic Feedback Discharges, Ningyu Liu, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

This paper reports a modeling study of terrestrial gamma ray flashes (TGFs) produced by relativistic feedback discharges. Terrestrial gamma ray flashes are intense energetic radiation originating from the Earth’s atmosphere that has been observed by spacecraft. They are produced by bremsstrahlung interactions of energetic electrons, known as runaway electrons, with air atoms. An efficient physical mechanism for producing large fluxes of the runaway electrons to make the TGFs is the relativistic feedback discharge, where seed runaway electrons are generated by positrons and X-rays, products of the discharge itself. Once the relativistic feedback discharge becomes self-sustaining, an exponentially increasing number of …

Radio Emissions From Terrestrial Gamma-Ray Flashes, Joseph R. Dwyer, Steven A. Cummer

Aerospace, Physics, and Space Science Faculty Publications

The theory of radio frequency (RF) emissions by terrestrial gamma-ray flashes (TGFs) is developed. These radio emissions, which are separate from the emission caused by lightning, are produced by the electric currents generated by runaway electrons and resulting low-energy electrons and ions. It is found from theory that the radio frequency pulses produced by TGFs are large enough to measure. Features of these signals depend strongly on certain aspects of the runaway acceleration process and so should provide additional information about the source mechanism(s) of this interesting atmospheric phenomenon. The RF emissions from several TGF models are calculated and compared …

Contribution Of The Pacific Decadal Oscillation To Global Mean Sea Level Trends, B. D. Hamlington, R. R. Leben, M. W. Strassburg, R. S. Nerem, K-Y. Kim

CCPO Publications

Understanding and explaining the trend in global mean sea level (GMSL) have important implications for future projections of sea level rise. While measurements from satellite altimetry have provided accurate estimates of GMSL, the modern altimetry record has only now reached 20 years in length, making it difficult to assess the contribution of decadal to multidecadal climate signals to the global trend. Here, we use a sea level reconstruction to study the 20 year trends in sea level since 1950. In particular, we show that the Pacific Decadal Oscillation (PDO) contributes significantly to the 20 year trends in GMSL. We estimate …

Intrusion Of Warm Surface Water Beneath The Mcmurdo Ice Shelf, Antarctica, A. A. Stern, M. S. Dinniman, V. Zagorodnov, S. W. Tyler, D. M. Holland

CCPO Publications

A 6 month temperature record collected below McMurdo Ice Shelf in 2011-2012 shows the temporal and spatial structure of the summertime warm water signal that penetrates beneath the ice shelf. The strength and duration of the warm water intrusion suggest an annual melt rate at Windless Bight of 0.71 m/yr. A Ross Sea numerical model demonstrates a seasonal warm water pathway leading from the west side of the Ross Sea Polynya (RSP) toward McMurdo Sound. The warm water enters McMurdo Sound, subducts beneath the ice shelf and causes accelerated summer melting. Temperature data were recorded using Distributed Temperature Sensing fiber …

An Analysis Of Surface Air Temperature Trends And Variability Along The Andes, Eric Franquist

Legacy Theses & Dissertations (2009 - 2024)

Climate change is difficult to study in mountainous regions such as the Andes since steep changes in elevation cannot always be resolved by climate models. However, it is important to examine temperature trends in this region as rises in surface air temperature are leading to the melting of tropical glaciers. Local communities rely on the glacier-fed streamflow to get their water for drinking, irrigation, and livestock. Moreover, communities also rely on the tourism of hikers who come to the region to view the glaciers. As the temperatures increase, these glaciers are no longer in equilibrium with their current climate and …

The Motion Of Mesoscale Snowbands In Northeast U.S. Winter Storms, Jaymes Kenyon

Legacy Theses & Dissertations (2009 - 2024)

The distribution of snowfall accumulation attending winter storms is a product of both precipitation intensity and duration. Many heavy snowfall events are associated with distinct mesoscale snowbands that strongly modulate snowfall accumulation. Mesoscale snowbands are known to be favored within environments characterized by frontogenesis in the presence of weak moist symmetric or gravitational stabilities. Although the development of mesoscale snowbands often can be anticipated at 24–36-h ranges, anticipating band residence time at a fixed location remains a forecasting challenge. However, given that snowband residence time is related to characteristics of band motion, improved understanding of band motion presents an opportunity …

Solar Radiation Measurements And Their Applications In Climate Research, Bangsheng Yin

Legacy Theses & Dissertations (2009 - 2024)

Aerosols and clouds play important roles in the climate system through their radiative effects and their vital link in the hydrological cycle. Accurate measurements of aerosol and cloud optical and microphysical properties are crucial for the study of climate and climate change. This study develops/improves retrieval algorithms for aerosol single scattering albedo (SSA) and low liquid water path (LWP) cloud optical properties, evaluates a new spectrometer, and applies long-term measurements to establish climatology of aerosol and cloud optical properties. The following results were obtained.

Interactions Between African Easterly Waves And Moist Convection, Matthew Adam Janiga

Legacy Theses & Dissertations (2009 - 2024)

African easterly waves (AEWs) over tropical Africa and the East Atlantic influence and are themselves influenced by moist convection. Data from the Tropical Rainfall Measuring Mission (TRMM) satellite, reanalyses, and in-situ observations are used to examine both directions of this two-way interaction.

Study Of Key Factors Influencing Dust Emission : An Assessment Of Geos-Chem And Dead Simulations With Observations, Kevin Scott Bartlett

Legacy Theses & Dissertations (2009 - 2024)

Mineral dust aerosols can impact air quality, climate change, biological cycles, tropical cyclone development and flight operations due to reduced visibility. Dust emissions are primarily limited to the extensive arid regions of the world, yet can negatively impact local to global scales, and are extremely complex to model accurately. Within this dissertation, the Dust Entrainment And Deposition (DEAD) model was adapted to run, for the first known time, using high temporal (hourly) and spatial (0.3°x0.3°) resolution data to methodically interrogate the key parameters and factors influencing global dust emissions. The dependence of dust emissions on key parameters under various conditions …

Evaluating Drought In The United States Using The Emissivity Difference Vegetation Index, Hanisha Hirani

Legacy Theses & Dissertations (2009 - 2024)

As monitoring vegetation and crops becomes increasingly important due to climate change, there arises the need for a monitoring scheme that places more weight on water availability as an indication of vegetation health and vitality. The Emissivity Difference Vegetation Index (EDVI) is the first step towards that type of monitoring scheme. With the potential for diurnal studies, there are applications towards agriculture monitoring, wildfire monitoring, and much more. EDVI is a synergetic product retrieved from microwave, visible, and infrared satellite measurements, as well as reanalysis. Since microwave measurements are more sensitive to vegetation water content, EDVI has the potential to …

Impacts Of Migratory Sandhill Cranes (Grus Canadensis) On Microbial Water Quality In The Central Platte River, Nebraska, Usa, Jason R. Vogel, Dale W. Griffin, Hon S. Ip, Nicholas J. Ashbolt, Matthew T. Moser, Jingrang Lu, Mary K. Beitz, Hodon Ryu, Jorge W. Santo Domingo

United States Geological Survey: Staff Publications

Wild birds have been shown to be significant sources of numerous types of pathogens that are relevant to humans and agriculture. The presence of large numbers of migratory birds in such a sensitive and important ecosystem as the Platte River in central Nebraska, USA, could potentially serve a significant source of birdderived pathogens in the water/sediment and riverine environment. In 2009 and 2010, a study was completed to investigate the potential water-quality impacts of Sandhill Cranes and Snow Geese on the microbial water quality of the central Platte River during their spring migration period. Fecal material, river-bottom sediment, and water …

Controls On Recent Alaskan Lake Changes Identified From Water Isotopes And Remote Sensing, Lesleigh Anderson, Jennifer Rover, Nikki Gaulager, Jean Birks

United States Geological Survey: Staff Publications

High-latitude lakes are important for terrestrial carbon dynamics and waterfowl habitat driving a need to better understand controls on lake area changes. To identify the existence and cause of recent lake area changes in the Yukon Flats, a region of discontinuous permafrost in north central Alaska, we evaluate remotely sensed imagery with lake water isotope compositions and hydroclimatic parameters. Isotope compositions indicate that mixtures of precipitation, river water, and groundwater source ~95% of the studied lakes. The remaining minority are more dominantly sourced by snowmelt and/or permafrost thaw. Isotope-based water balance estimates indicate 58% of lakes lose more than half …

Ice-Age Megafauna In Arctic Alaska: Extinction, Invasion, Survival, Daniel H. Mann, Pamela Groves, Michael L. Kunz, Richard E. Reanier, Benjamin V. Gaglioti

United States Geological Survey: Staff Publications

Radical restructuring of the terrestrial, large mammal fauna living in arctic Alaska occurred between 14,000 and 10,000 years ago at the end of the last ice age. Steppe bison, horse, and woolly mammoth became extinct, moose and humans invaded, while muskox and caribou persisted. The ice age mega fauna was more diverse in species and possibly contained 6x more individual animals than live in the region today. Mega faunal biomass during the last ice age may have been 30x greater than present. Horse was the dominant species in terms of number of individuals. Lions, short-faced bears, wolves, and possibly grizzly …

Loess And Its Geomorphic, Stratigraphic, And Paleoclimatic Significance In The Quaternary, Daniel R. Muhs

United States Geological Survey: Staff Publications

Loess is aeolian silt visible in the field as a sedimentary body. It covers a significant portion of the land surface of the Earth. Loess thickness, particle size, and carbonate content decrease downwind from sources, useful trends for paleowinds. Many loess sections consist of relatively thick deposits of mostly unaltered sediment with intercalated paleosols. Paleosols represent periods of landscape stability when loess deposition slowed significantly. Loess in most regions was deposited during glacial periods and paleosols formed during interglacial periods. Loess has the potential to record the timing and environment of glacial–interglacial cycles of the Quaternary on many continents.

Assessing Total Nitrogen In Surface-Water Samples: Precision And Bias Of Analytical And Computational Methods, David L. Rus, Charles J. Patton, David K. Mueller, Charles G. Crawford

United States Geological Survey: Water Reports and Publications

The characterization of total-nitrogen (TN) concentrations is an important component of many surface-water-quality programs. However, three widely used methods for the determination of total nitrogen—(1) derived from the alkaline-persulfate digestion of whole-water samples (TN-A); (2) calculated as the sum of total Kjeldahl nitrogen and dissolved nitrate plus nitrite (TN-K); and (3) calculated as the sum of dissolved nitrogen and particulate nitrogen (TN-C)—all include inherent limitations. A digestion process is intended to convert multiple species of nitrogen that are present in the sample into one measureable species, but this process may introduce bias. TN-A results can be negatively biased in the …

Riparian Evapotranspiration In Nebraska, Brent M. Hall, David L. Rus

United States Geological Survey: Water Reports and Publications

With increasing demands being placed on the water resources of Nebraska, characterizing evapotranspiration (ET) from riparian vegetation has gained importance to water users and managers. This report summarizes and compares the results from several studies of the ET from cottonwood-dominated riparian forests, riparian grasslands, and common reed, Phragmites australis, in Nebraska. Reported results show that the highest seasonal ET amounts were associated with Phragmites australis, followed by riparian forests, with riparian grasslands experiencing the lowest total ET of the studied vegetation communities.

Numerical Modeling Of Lightning Initiation And Stepped Leader Propagation, Sumedhe Karunarathne

Electronic Theses and Dissertations

Initial breakdown pulses (IBPs) observed at the beginning of cloud-to-ground (CG) lightning flashes and stepped leaders that folloIBPs were modeled using multi-sensor electric field change (E-change) measurements. This study uses data collected with a network of ten E-change sensors located at Kennedy Space Center. Locations (x,y,z,t) of IBPs were found using a time-of-arrival technique called PBFA. Location errors were determined from Monte Carlo simulations and were usually less than 100 m for horizontal coordinates and several hundreds of meters for altitude. Comparison of PBFA source locations to locations from a VHF lightning mapping system shows that PBFA locates most of …

Short-Term Denitrification In The Metalimnion Of A Eutrophic Reservoir, Aki Kogo, Erin M. Grantz, Thad Scott

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Denitrification in metalimnetic water was examined under different conditions to determine how addition of nitrate (NO3 -) and particulate carbon (PC), aeration, and concentrations of nitrate affect denitrification. In the first experiment, water samples from a metalimnion were treated with different combinations of NO3 - and PC. Changes in excess N2 -N concentration for 10 days were measured using membrane inlet mass spectrometry (MIMS). The second experiment used the same treatments as the first experiment after aeration of water. Besides excess N2 -N concentrations, O2 concentrations were measured for 16 days. The third experiment examined how different initial concentrations of …

Inter- And Intra-Annual Variability Of Vegetation In The Northern Hemisphere And Its Association With Precursory Meteorological Factors, Boksoon Myoung, Yong-Sang Choi, Seungbum Hong, Seon Ki Park

Mathematics, Physics, and Computer Science Faculty Articles and Research

Determination of phenological variation is one of the most critical challenges in dynamic vegetation modeling, given the lack of a strong theoretical framework. Previous studies generally focused on the timing of a phenological event (e.g., bud-burst or onset of growing season) and its atmospheric prompts, but not on the interactive variations across phenological stages. This study, therefore, investigated the inter- and intra-annual variability existing in all the phenological stages and the relations of the variability with four meteorological variables (surface temperature (Ts), shortwave radiation (SW ), vapor pressure deficit (VPD), and precipitation (PRCP)) using a 25-year (1982-2006) dataset of leaf …

Impacts Of Predicted Global Sea-Level Rise On Oregon Beaches And Tidelands, Curt D. Peterson

Geology Faculty Publications and Presentations

Forward by:

Phillip Johnson, Executive Director Oregon Shores Conservation Coalition

The Oregon Shores Conservation Coalition’s "Coastal Climate Change Adaptation Project" is under development as an experiment in grassroots organizing for adaptive planning for expected climate change impacts. Oregon Shores is a regional conservation group with a 40-year history of working to protect marine, shoreline, estuarine and other coastal habitats. The organization’s board and staff came to recognize that the likely effects of climate change—rising sea levels, more intensive storm surges, increased erosion, lower-river flooding, among others—would affect every aspect of the group’s work. Consequently, a new program, the Climate Action …

Incorporating Science-Based Approaches Into The Rapid Assessment Of Wetlands And Streams : Validation, Restoration Trajectory, And Method Development, Jacob Franklin Berkowitz

LSU Doctoral Dissertations

Human alterations within wetlands and streams have resulted in a decrease in ecological functions and associated benefits to society. The scientific literature highlights the functional benefits provided by ecosystems including flood protection, nutrient cycling, and habitat maintenance. Additionally, legislation and regulatory policy require mitigation and restoration as compensation for declines in ecological functions. As a result, the need for practical, repeatable, and technically sound ecosystem assessment methods remains essential to natural resource management. However, few studies determine the validity of rapid assessment approaches by applying quantitative parameters, especially with respect to biogeochemical functions. We assessed biogeochemical functions applied to restored …