Oceanography and Atmospheric Sciences and Meteorology Commons^™

Ice Sheet Record Of Recent Sea-Ice Behavior And Polynya Variability In The Amundsen Sea, West Antarctica, Alison S. Criscitiello, Sarah B. Das, Matthew J. Evans, Karen E. Frey, Howard Conway, Ian Joughin, Brooke Medley, Eric J. Steig

Geography

[1] Our understanding of past sea-ice variability is limited by the short length of satellite and instrumental records. Proxy records can extend these observations but require further development and validation. We compare methanesulfonic acid (MSA) and chloride (Cl-) concentrations from a new firn core from coastal West Antarctica with satellite-derived observations of regional sea-ice concentration (SIC) in the Amundsen Sea (AS) to evaluate spatial and temporal correlations from 2002-2010. The high accumulation rate (∼39 g·cm-2·yr-1) provides monthly resolved records of MSA and Cl-, allowing detailed investigation of how regional SIC is recorded in the ice-sheet stratigraphy. Over the period 2002-2010 …

Turbulent Collision-Coalescence In Maritime Shallow Convection, A. A. Wyszogrodzki, W.W. Grabowski, L. P. Wang, Orlando Ayala

Engineering Technology Faculty Publications

This paper discusses cloud simulations aiming at quantitative assessment of the effects of cloud turbulence on rain development in shallow ice-free convective clouds. Cloud fields from large-eddy simulations (LES) applying bin microphysics with the collection kernel enhanced by cloud turbulence are compared to those with the standard gravitational collection kernel. Simulations for a range of cloud condensation nuclei (CCN) concentrations are contrasted. Details on how the parameterized turbulent collection kernel is used in LES simulations are presented. Because of the disparity in spatial scales between the bottom-up numerical studies guiding the turbulent kernel development and the top-down LES simulations of …

Terpene And Terpenoid Emissions And Secondary Organic Aerosol Production, Rosa M. Flores

Dissertations, Master's Theses and Master's Reports - Open

Approximately 90% of fine aerosol in the Midwestern United States has a regional component with a sizable fraction attributed to secondary production of organic aerosol (SOA). The Ozark Forest is an important source of biogenic SOA precursors like isoprene (> 150 mg m^-2 d^-1), monoterpenes (10-40 mg m^-2 d^-1), and sesquiterpenes (10-40 mg m^-2d^-1). Anthropogenic sources include secondary sulfate and nitrate and biomass burning (51-60%), vehicle emissions (17-26%), and industrial emissions (16-18%). Vehicle emissions are an important source of volatile and vapor-phase, semivolatile aliphatic and aromatic hydrocarbons that are important …

Investigations Of Cloud Microphysical Response To Mixing Using Digital Holography, Matthew Jacob Beals

Dissertations, Master's Theses and Master's Reports - Open

Cloud edge mixing plays an important role in the life cycle and development of clouds. Entrainment of subsaturated air affects the cloud at the microscale, altering the number density and size distribution of its droplets. The resulting effect is determined by two timescales: the time required for the mixing event to complete, and the time required for the droplets to adjust to their new environment. If mixing is rapid, evaporation of droplets is uniform and said to be homogeneous in nature. In contrast, slow mixing (compared to the adjustment timescale) results in the droplets adjusting to the transient state of …

A Multi-Scale Investigation Of Nutrient Dynamics In The Lake Pontchartrain Estuary And Basin, Eric Daniel Roy

LSU Doctoral Dissertations

Humans are responsible for global-scale alteration of nitrogen (N) and phosphorus (P) biogeochemical cycles to support food production. Increases in N and P inputs into soils and waste-streams has resulted in excessive nutrient loading to surface waters, including the Mississippi River, leading to eutrophication. Here I investigated N and P dynamics occurring in the Lake Pontchartrain Estuary and Basin. I measured two biogeochemical processes using intact sediment core incubations and quantified their importance in the context of nutrient-rich Mississippi River flood diversions through the Bonnet Carré Spillway. I show that diffusion of nitrate-N into sediments accounts for a substantial magnitude …

Trophic Ecology Of Oxygen Minimum Zone Zooplankton Revealed By Carbon And Nitrogen Stable Isotopes, Rebecca Williams

Open Access Dissertations

Oxygen minimum zones (OMZs) are areas in which midwater oxygen concentration can be significantly lower than in non OMZ areas at comparable depths. OMZs are of great interest because of the limits oxygen availability places on life. The potential for OMZ expansion with warming of the oceans has refocused attention on the importance of these areas and their potential impacts on the global carbon cycle. The large open ocean OMZs of the Eastern Tropical Pacific and Arabian Sea are notable for their size, thickness, and the intensity of oxygen depletion (

Here, I use measurements of natural abundance carbon and …

Metr 200: Weather And Climate—A Peer Review Of Teaching Project Benchmark Portfolio, Matthew S. Van Den Broeke

UNL Faculty Course Portfolios

This benchmark portfolio is meant to be an assessment of how well the objectives of METR 200 (Weather and Climate) are being attained by students in several classifications of academic major. Students from a wide range of backgrounds enroll in this course as a general science elective, and for many, it will be the only science course taken in college. Thus, it is important that course material be sufficiently accessible for all students, while providing meaningful information which will be applicable by students of all backgrounds once they leave the course. In this portfolio, an analysis will be presented showing …

Metr 323: Physical Meteorology—A Peer Review Of Teaching Project Benchmark Portfolio, Jun Wang

UNL Faculty Course Portfolios

Hands-on out-door activities are added into a course that is designed to teach students atmospheric physics ranging form solar light transfer to cloud and precipitation formation in the atmosphere. Statistical analysis and anonymous survey are conducted to benchmark the improvement in students' learning. Results show that these hands-on activities increase the student's interest and understanding in the course materials, and also improve the overall students' satisfaction for the course.

The Educational Training Of Storm Chasers And Storm Spotters In Relation To Geographical Dispersion Across The United States, Paul R. Zunkel

All Graduate Theses, Dissertations, and Other Capstone Projects

When severe weather strikes, storm chasers and storm spotters confirm that what forecasters and meteorologists are seeing on a radar screen is actually occurring in the field. While some documenters are classically trained (i.e. they have a background in atmospheric science and or meteorology attained from a 4 year university) many others are not. There are currently two organizations available for the weather enthusiast to be a part of, SKYWARN and SpotterNetwork. These organizations give weather enthusiasts a background knowledge into severe weather; however, many weather enthusiasts are not classically trained and most have not taken any formal education in …

Uncertainties In Modelling Heterogeneous Chemistry And Arctic Ozone Depletion In The Winter 2009/2010, I. Wohltmann, T. Wegner, R. Müller, R. Lehmann, M. Rex, G. L. Manney, M. L. Santee, P. Bernath, O. Suminska-Ebersoldt

Chemistry & Biochemistry Faculty Publications

Stratospheric chemistry and denitrification are simulated for the Arctic winter 2009/2010 with the Lagrangian Chemistry and Transport Model ATLAS. A number of sensitivity runs is used to explore the impact of uncertainties in chlorine activation and denitrification on the model results. In particular, the efficiency of chlorine activation on different types of liquid aerosol versus activation on nitric acid trihydrate clouds is examined. Additionally, the impact of changes in reaction rate coefficients, in the particle number density of polar stratospheric clouds, in supersaturation, temperature or the extent of denitrification is investigated. Results are compared to satellite measurements of MLS and …

Depositional History Of The Trinity-Tiger Shoals Region : A Transgressed Delta Complex Of The Middle Holocene Mississippi Delta, Clint Hoyt Edrington

LSU Doctoral Dissertations

The Holocene Mississippi River Delta is arguably the world’s most thoroughly researched deltaic system. However, much of this research has occurred predominantly within the present-day subaerial delta, whereas comparatively little research has been attempted downdip within the offshore, more difficult-to-reach parts. This study advances our understanding of the Holocene delta by examining deltaic sediments within the Trinity-Tiger Shoals Complex region, located ~ 30 – 40 km offshore of central Louisiana. Specifically, this study addresses two questions. Which delta complex prograded into this offshore region? Do the overlying transgressive deposits reflect that predicted by the prevailing transgressive depositional systems model? To …

Reef Fish Demographics On Louisiana Artificial Reefs : The Effects Of Reef Size On Biomass Distribution And Foraging Dynamics, Kirsten A. Simonsen

LSU Doctoral Dissertations

Understanding the role that habitat plays in the life history of reef-associated fishes is particularly significant given the dramatic increase in the number of artificial reefs deployed in coastal ecosystems over the past 50 years. In the Gulf of Mexico, the oil and gas industry has added a significant amount of structure to the Louisiana continental shelf, creating the largest de facto artificial reef deployment area in the world. Noting their usefulness as fish habitat, the Louisiana Artificial Reef Program was established to convert decommissioned platforms into artificial reefs. However, very little quantitative information exists on how these habitats affect …

A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur

Antioch University Dissertations & Theses

This study investigated a terrestrial climate proxy, phytoliths, as a complimentary approach to documenting the dynamics of present and past vegetation on Sanak Island, the largest island in a small island group in the eastern Aleutian archipelago, and as a new basis by which to interpret Holocene environmental variability in Alaska. A phytolith reference collection was established from 59 selected plant species of maritime tundra belonging to 27 families. The grass species and a sedge species produced abundant phytolith forms whereas the majority of dicotyledons in this study were trace producers of phytoliths. A paleoenvironmental reconstruction from fossil phytoliths recovered …

Combining Angular And Spatial Information From Multibeam Backscatter Data For Improved Unsupervised Acoustic Seabed Segmentation, Alexandre C. Schimel, Yuri Rzhanov, Luciano E. Fonseca, M Mayer, Dirk Immenga

Center for Coastal and Ocean Mapping

No abstract provided.

Seabed Classification For Trawlability Determined With A Multibeam Echo Sounder On Snakehead Bank In The Gulf Of Alaska, Thomas C. Weber, Chris Rooper, John L. Butler, Darin Jones, Chris Wilson

Center for Coastal and Ocean Mapping

—Rockfishes (Sebastes spp.) tend to aggregate near rocky, cobble, or generally rugged areas that are difficult to survey with bottom trawls, and evidence indicates that assemblages of rockfish species may differ between areas accessible to trawling and those areas that are not. Consequently, it is important to determine grounds that are trawlable or untrawlable so that the areas where trawl survey results should be applied are accurately identified. To this end, we used multibeam echosounder data to generate metrics that describe the seafloor: backscatter strength at normal and oblique incidence angles, the variation of the angle-dependent backscatter strength within 10° …

A Procedure For Developing An Acceptance Test For Airborne Bathymetric Lidar Data Application To Noaa Charts In Shallow Waters, Gretchen Imahori, Jeffrey Ferguson, Toshi Wozumi, Dave Scharff, Shachak Pe'eri, Christopher Parrish, Stephen A. White, Inseong Jeong, Jon Sellars, Michael Aslaksen

Center for Coastal and Ocean Mapping

National Oceanic and Atmospheric Administration (NOAA) hydrographic data is typically acquired using sonar systems, with a small percent acquired via airborne lidar bathymetry for near‐shore areas. This study investigated an integrated approach for meeting NOAA’s hydrographic survey requirements for near‐shore areas of NOAA charts, using the existing topographic‐bathymetric lidar data from USACE’s National Coastal Mapping Program (NCMP). Because these existing NCMP bathymetric lidar datasets were not collected to NOAA hydrographic surveying standards, it is unclear if, and under what circumstances, they might aid in meeting certain hydrographic surveying requirements. The NCMP’s bathymetric lidar data are evaluated through a comparison to …

Ricamar2013: Rilievi Per La Caratterizzazione Dell'ambiente Marino Nel Golfo Di Pozzuoli. Rapporto Sull'attivita 13 - 31 Maggio 2013, C. Carmisciano, M. Grassi, L. Cocchi, Giuseppe Masetti, M. Filippone, E. Ricci, M. Pratellesi, Roberta Ivaldi, Giovanni Iannaccone, Giovanna Berrino, Guiseppe De Natale, Giovanni Chiodini, Sefano Caliro, Lorenzo Dialti, Matteo Guideri, F. Muccini, Paolo Stefanelli, Giovanni Orsi, Valerio Iafolla, Francesco Italiano, Fabrizia Buongiorno, Salvatore Stramondo, Christian Bignami, Marco Polcari, Malvina Silvestri

Center for Coastal and Ocean Mapping

No abstract provided.

Cave Ventilation Is Influenced By Variations In The Co2-Dependent Virtual Temperature, Enrique P. Sánchez-Cañete, Penélope Serrano-Ortiz, Francisco Domingo, Andrew S. Kowalski

International Journal of Speleology

Dynamics and drivers of ventilation in caves are of growing interest for different fields of science. Accumulated CO₂ in caves can be exchanged with the atmosphere, modifying the internal CO₂ content, affecting stalagmite growth rates, deteriorating rupestrian paintings or creating new minerals. Current estimates of cave ventilation neglect the role of high CO₂ concentrations in determining air density – approximated via the virtual temperature (T_v) –, affecting buoyancy and therefore the release or storage of CO₂. Here we try to improve knowledge and understanding of cave ventilation through the use of T …

Spatial And Temporal Trends Of Snowfall In Central New York - A Lake Effect Dominated Region, Justin Joseph Hartnett

USF Tampa Graduate Theses and Dissertations

Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as …

Biochemical Aspects Of The Thermal Sensitivity And Energy Balance Of Polar, Tropical And Subtropical Teleosts, Eloy Martinez

USF Tampa Graduate Theses and Dissertations

The maintenance of a functional energy balance in ectothermic fauna could be challenging in a thermally disparate environment. Biochemical adaptations at the enzyme and membrane levels allows for a set compensatory mechanism that allow the individual to maintain an energetic surplus, thus allocating energy for growth and reproduction. The present work describes how the energetic machinery in the cell, particularly the mitochondrion, could be affected by temperature changes. More specifically, this work aimed to determine how environmental temperature affects the mitochondria energetic performance of fishes from disparate thermal regimes.

Mitochondrial ATP production efficiency was evaluated in fishes from polar, tropical …