Global Stratospheric Fluorine Inventory For 2004-2009 From Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Measurements And Slimcat Model Simulations,
2014
Old Dominion University
Global Stratospheric Fluorine Inventory For 2004-2009 From Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Measurements And Slimcat Model Simulations, A. T. Brown, M. P. Chipperfield, N. A. D. Richards, C. Boone, P. F. Bernath
Chemistry & Biochemistry Faculty Publications
Fluorine-containing species can be extremely effective atmospheric greenhouse gases. We present fluorine budgets using organic and inorganic species retrieved by the ACE-FTS satellite instrument supplemented with output from the SLIMCAT 3-D chemical transport model. The budgets are calculated between 2004 and 2009 for a number of latitude bands: 70-30 °N, 30-00 °N, 00 °N-30 °S, and 30-70°S. At lower altitudes total fluorine profiles are dominated by the contribution from CFC-12, up to an altitude of 20 km in the extra-tropics and 29 km in the tropics; above these altitudes the profiles are dominated by hydrogen fluoride (HF). Our data show …
Technical Note: Swift - A Fast Semi-Empirical Model For Polar Stratospheric Ozone Loss,
2014
Old Dominion University
Technical Note: Swift - A Fast Semi-Empirical Model For Polar Stratospheric Ozone Loss, M. Rex, S. Kremser, P. Huck, G. Bodeker, I. Wohltmann, M. L. Santee, P. F. Bernath
Chemistry & Biochemistry Faculty Publications
An extremely fast model to estimate the degree of stratospheric ozone depletion during polar winters is described. It is based on a set of coupled differential equations that simulate the seasonal evolution of vortex-averaged hydrogen chloride (HCl), nitric acid (HNO3), chlorine nitrate (ClONO2), active forms of chlorine (ClOx = Cl+ClO+2ClOOCl) and ozone (O3) on isentropic levels within the polar vortices. Terms in these equations account for the chemical and physical processes driving the time rate of change of these species. Eight empirical fit coefficients associated with these terms are derived by iteratively fitting the equations …
Derivation Of Tropospheric Methane From Tccon Ch4 And Hf Total Column Observations,
2014
Old Dominion University
Derivation Of Tropospheric Methane From Tccon Ch4 And Hf Total Column Observations, K. M. Saad, D. Wunch, P. Bernath, C. Boone, B. Connor, N. M. Deutscher, D.W.T. Griffith, R. Kivi, J. Notholt, C. Roehl, M. Schneider, V. Sherlock, P. O. Wennberg
Chemistry & Biochemistry Faculty Publications
The Total Carbon Column Observing Network (TCCON) is a global ground-based network of Fourier transform spectrometers that produce precise measurements of column-averaged dry-air mole fractions of atmospheric methane (CH4). Temporal variability in the total column of CH4 due to stratospheric dynamics obscures fluctuations and trends driven by tropospheric transport and local surface fluxes that are critical for understanding CH4 sources and sinks. We reduce the contribution of stratospheric variability from the total column average by subtracting an estimate of the stratospheric CH4 derived from simultaneous measurements of hydrogen fluoride (HF). HF provides a proxy for …
Middle Atmospheric Changes Caused By The January And March 2012 Solar Proton Events,
2014
Old Dominion University
Middle Atmospheric Changes Caused By The January And March 2012 Solar Proton Events, C. H. Jackman, C. E. Randall, V. L. Harvey, S. Wang, E. L. Fleming, M. López-Puertas, B. Funke, P. F. Bernath
Chemistry & Biochemistry Faculty Publications
The recent 23-30 January and 7-11 March 2012 solar proton event (SPE) periods were substantial and caused significant impacts on the middle atmosphere. These were the two largest SPE periods of solar cycle 24 so far. The highly energetic solar protons produced considerable ionization of the neutral atmosphere as well as HOx (H, OH, HO2) and NOx (N, NO, NO2). We compute a NOx production of 1.9 and 2.1 Gigamoles due to these SPE periods in January and March 2012, respectively, which places these SPE periods among the 12 largest in the past 50 yr. Aura Microwave Limb Sounder (MLS) …
Morphology And Mixing State Of Atmospheric Particles: Links To Optical Properties And Cloud Processing,
2014
Michigan Technological University
Morphology And Mixing State Of Atmospheric Particles: Links To Optical Properties And Cloud Processing, Swarup China
Dissertations, Master's Theses and Master's Reports - Open
Atmospheric particles are ubiquitous in Earth’s atmosphere and impact the environment and the climate while affecting human health and Earth’s radiation balance, and degrading visibility. Atmospheric particles directly affect our planet’s radiation budget by scattering and absorbing solar radiation, and indirectly by interacting with clouds. Single particle morphology (shape, size and internal structure) and mixing state (coating by organic and inorganic material) can significantly influence the particle optical properties as well as various microphysical processes, involving cloud-particle interactions and including heterogeneous ice nucleation and water uptake. Conversely, aerosol cloud processing can affect the morphology and mixing of the particles. For …
Investigating The Role Of The Contact Line In Heterogeneous Nucleation With High Speed Imaging,
2014
Michigan Technological University
Investigating The Role Of The Contact Line In Heterogeneous Nucleation With High Speed Imaging, Colin Gurganus
Dissertations, Master's Theses and Master's Reports - Open
While nucleation of solids in supercooled liquids is ubiquitous [15, 65, 66], surface crystallization, the tendency for freezing to begin preferentially at the liquid-gas interface, has remained puzzling [74, 18, 68, 69, 51, 64, 72, 16]. Here we employ high-speed imaging of supercooled water drops to study the phenomenon of heterogeneous surface crystallization. Our geometry avoids the "point-like contact" of prior experiments by providing a simple, symmetric contact line (triple line defined by the substrate-liquid-air interface) for a drop resting on a homogeneous silicon substrate. We examine three possible mechanisms that might explain these laboratory observations: (i) Line Tension at …
Tropical Pacific Influence On The Source And Transport Of Marine Aerosols To West Antarctica,
2014
Massachusetts Institute of Technology
Tropical Pacific Influence On The Source And Transport Of Marine Aerosols To West Antarctica, Alison S. Criscitiello, Sarah B. Das, Kristopher B. Karnauskas, Matthew J. Evans, Karen E. Frey, Ian Joughin, Eric J. Steig, Joseph R. Mcconnell, Brooke Medley
Geography
The climate of West Antarctica is strongly influenced by remote forcing from the tropical Pacific. For example, recent surface warming over West Antarctica reflects atmospheric circulation changes over the Amundsen Sea, driven by an atmospheric Rossby wave response to tropical sea surface temperature (SST) anomalies. Here, it is demonstrated that tropical Pacific SST anomalies also influence the source and transport of marine-derived aerosols to theWest Antarctic Ice Sheet. Using records from four firn cores collected along the Amundsen coast of West Antarctica, the relationship between sea ice-modulated chemical species and large-scale atmospheric variability in the tropical Pacific from 1979 to …
Characterizing The Tgt-Lightning Relationship Using Entln,
2014
University of Alabama in Huntsville
Characterizing The Tgt-Lightning Relationship Using Entln, Kareem Omar
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
Impact Of Desert Dust And Biomass Burning On The Radiative Budget Of The Sahel,
2014
University of Alabama in Huntsville
Impact Of Desert Dust And Biomass Burning On The Radiative Budget Of The Sahel, Christopher Phillips
Summer Community of Scholars Posters (RCEU and HCR Combined Programs)
No abstract provided.
Two-Source Energy Balance Model To Calculate E, T, And Et: Comparison Of Priestley-Taylor And Penman-Monteith Formulations And Two Time Scaling Methods,
2014
United States Department of Agriculture, Agricultural Research Service
Two-Source Energy Balance Model To Calculate E, T, And Et: Comparison Of Priestley-Taylor And Penman-Monteith Formulations And Two Time Scaling Methods, Paul D. Colaizzi, Nurit Agam, Judy A. Tolk, Steven R. Evett, Terry A. Howell, Prasanna H. Gowda, Susan A. O'Shaughnessy, William P. Kustas, Martha C. Anderson
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
The two-source energy balance (TSEB) model calculates the energy balance of the soil-canopy-atmosphere continuum, where transpiration is initially determined by the Priestley-Taylor equation. The TSEB was revised recently using the Penman-Monteith equation to replace the Priestley-Taylor formulation, thus better accounting for the impact of large and varying vapor pressure deficits (VPD) typical of advective, semiarid climates. This study is a comparison of the Priestley- Taylor and Penman-Monteith versions of the TSEB (termed TSEB-PT and TSEB-PM, respectively). Evaporation (E), transpiration (T), and evapotranspiration (ET) calculated by the TSEB-PT and TSEB-PM versions were compared to measurements obtained with microlysimeters, sap flow gauges, …
Characterization Of The Atmospheric Effects On The Transmission Of Thermal Radiation,
2014
Michigan Technological University
Characterization Of The Atmospheric Effects On The Transmission Of Thermal Radiation, Mohamed E. Hanafy
Dissertations, Master's Theses and Master's Reports - Open
Atmospheric scattering plays a crucial rule in degrading the performance of electro optical imaging systems operating in the visible and infra-red spectral bands, and hence limits the quality of the acquired images, either through reduction of contrast or increase of image blur. The exact nature of light scattering by atmospheric media is highly complex and depends on the types, orientations, sizes and distributions of particles constituting these media, as well as wavelengths, polarization states and directions of the propagating radiation. Here we follow the common approach for solving imaging and propagation problems by treating the propagating light through atmospheric media …
Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model,
2014
Michigan Technological University
Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model, Keenan Anton Murray
Dissertations, Master's Theses and Master's Reports - Open
This work presents a 1-D process scale model used to investigate the chemical dynamics and temporal variability of nitrogen oxides (NOx) and ozone (O3) within and above snowpack at Summit, Greenland for March-May 2009 and estimates surface exchange of NOx between the snowpack and surface layer in April-May 2009. The model assumes the surface of snowflakes have a Liquid Like Layer (LLL) where aqueous chemistry occurs and interacts with the interstitial air of the snowpack. Model parameters and initialization are physically and chemically representative of snowpack at Summit, Greenland and model results are compared to …
Metr 341: Synoptic Meteorology—A Peer Review Of Teaching Project Inquiry Project,
2014
University of Nebraska-Lincoln
Metr 341: Synoptic Meteorology—A Peer Review Of Teaching Project Inquiry Project, Matthew S. Van Den Broeke
UNL Faculty Course Portfolios
Synoptic meteorology is foundational to atmospheric science, and it is critical that students strengthen their ability to think critically and independently in this course. Anecdotal evidence from teaching similar courses, and from education literature in the physical sciences, has pointed to the value of problem solving using data from real events. This inquiry project allowed further investigation of optimal instructional methods for this particular course, and led to the qualitative and partially quantified conclusion that hands-on in-class activities seem to support the most significant learning gains. In addition, this project led to the conclusion that a high degree of peer …
Wetlands And Greenhouse Gas Fluxes: Causes And Effects Of Climate Change – A Meta-Analysis,
2014
Pomona College
Wetlands And Greenhouse Gas Fluxes: Causes And Effects Of Climate Change – A Meta-Analysis, Robert E. Ventura
Pomona Senior Theses
Climate change is one of the largest problems facing this generation. Anthropogenically caused increases of greenhouse gas emissions is a significant culprit to this problem. Although the obvious problems such as cars, industry, and urbanism garnish a significant amount of the criticism, natural sources such as wetlands are also beginning to contribute to this issue. This is becoming increasingly significant as wetlands shift from being sinks of greenhouse gases to becoming sources as various anthropogenic impacts, including global warming itself, begin to affect the health of the wetlands. The aim of this project is to look at four common types …
Light Scattering From Aerosol Particles In The El Paso Del Norte Region / The Effect Of Humidity,
2014
University of Texas at El Paso
Light Scattering From Aerosol Particles In The El Paso Del Norte Region / The Effect Of Humidity, Richard Medina Calderon
Open Access Theses & Dissertations
Atmospheric aerosols play an important role in climate forcing, through scattering and absorption of the incoming solar radiation. The extinction of light by the presence of atmospheric aerosols was studied using two first-principle models, and corresponding computer codes. In the first model the extinction of light from irregularly shaped aerosol particles was analyzed. In the second model it was assumed that the irregularly shaped aerosol particles were covered by a film of water, and the hygroscopicity and the extinction of light by the aerosols was analyzed. These models were then applied to the Paso del Norte region and their light …
Long-Range Propagation, Interaction, And Dissipation Of Small-Scale Gravity Waves In The Mesosphere And Lower Thermosphere,
2014
Embry-Riddle Aeronautical University
Long-Range Propagation, Interaction, And Dissipation Of Small-Scale Gravity Waves In The Mesosphere And Lower Thermosphere, Christopher J. Heale
Doctoral Dissertations and Master's Theses
A 2-D nonlinear, compressible numerical model [Snively and Pasko, 2008] is used in conjunction with ray-theory to investigate the long-range propagation, dissipation and interaction of small-scale gravity waves in the Mesosphere and Lower Thermosphere (MLT) region. The research in this thesis is made up of three distinct studies which build upon each other. The first investigates the thermospheric dissipation of three gravity wave packets representing: (1) A quasi-monochromatic packet, (2) A monochromatic, steady state wave, and (3) A spectrally broad packet, as well as an initial condition specified packet. It is found that dissipation due to molecular viscosity and …
Effects Of Crop Residue Burning On Aerosol Properties, Plume Characteristics, And Long-Range Transport Over Northern India,
2014
Shiv Nadar University, India
Effects Of Crop Residue Burning On Aerosol Properties, Plume Characteristics, And Long-Range Transport Over Northern India, D. G. Kaskaoutis, S. Kumar, D. Sharma, Ramesh P. Singh, S. K. Kharol, M. Sharma, A. K. Singh, Atinderpal Singh, D. Singh
Mathematics, Physics, and Computer Science Faculty Articles and Research
Aerosol emissions from biomass burning are of specific interest over the globe due to their strong radiative impacts and climate implications. The present study examines the impact of paddy crop residue burning over northern India during the postmonsoon (October-November) season of 2012 on modification of aerosol properties, as well as the long-range transport of smoke plumes, altitude characteristics, and affected areas via the synergy of ground-based measurements and satellite observations. During this period, Moderate Resolution Imaging Spectroradiometer (MODIS) images show a thick smoke/hazy aerosol layer below 2-2.5 km in the atmosphere covering nearly the whole Indo-Gangetic Plains (IGP). The air …
Regional Dust Storm Modeling For Health Services: The Case Of Valley Fever,
2014
Chapman University
Regional Dust Storm Modeling For Health Services: The Case Of Valley Fever, William A. Sprigg, Slobodan Nickovic, John N. Galgiani, Goran Pejanovic, Slavo Petkovic, Mirjam Vujadinovic, Ana Vukovic, Milan Dacic, Scott Dibiase, Anup K. Prasad, Hesham El-Askary
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
On 5 July 2011, a massive dust storm struck Phoenix, Arizona (USA), raising concerns for increased cases of valley fever (coccidioidomycosis, or, cocci). A quasi-operational experimental airborne dust forecast system predicted the event and provides model output for continuing analysis in collaboration with public health and air quality communities. An objective of this collaboration was to see if a signal in cases of valley fever in the region could be detected and traced to the storm - an American haboob. To better understand the atmospheric life cycle of cocci spores, the DREAM dust model (also herein, NMME-DREAM) was modified to …
Numerical Simulation Of “An American Haboob”,
2014
University of Belgrade
Numerical Simulation Of “An American Haboob”, A. Vukovic, M. Vujadinovic, G. Pejanovic, J. Andric, M. J. Kumjian, V. Djurdjevic, M. Dacic, Anup K. Prasad, Hesham El-Askary, B. C. Paris, S. Petkovic, W. Sprigg, S. Nickovic
Mathematics, Physics, and Computer Science Faculty Articles and Research
A dust storm of fearful proportions hit Phoenix in the early evening hours of 5 July 2011. This storm, an American haboob, was predicted hours in advance because numerical, land–atmosphere modeling, computing power and remote sensing of dust events have improved greatly over the past decade. High-resolution numerical models are required for accurate simulation of the small scales of the haboob process, with high velocity surface winds produced by strong convection and severe downbursts. Dust productive areas in this region consist mainly of agricultural fields, with soil surfaces disturbed by plowing and tracks of land in the high Sonoran Desert …
The Great 2012 Arctic Ocean Summer Cyclone Enhanced Biological Productivity On The Shelves,
2014
Old Dominion University
The Great 2012 Arctic Ocean Summer Cyclone Enhanced Biological Productivity On The Shelves, Jinlun Zhang, Carin Ashjian, Robert Campbell, Victoria Hill, Yvette H. Spitz, Michael Steele
OES Faculty Publications
A coupled biophysical model is used to examine the impact of the great Arctic cyclone of early August 2012 on the marine planktonic ecosystem in the Pacific sector of the Arctic Ocean (PSA). Model results indicate that the cyclone influences the marine planktonic ecosystem by enhancing productivity on the shelves of the Chukchi, East Siberian, and Laptev seas during the storm. Although the cyclone's passage in the PSA lasted only a few days, the simulated biological effects on the shelves last 1 month or longer. At some locations on the shelves, primary productivity (PP) increases by up to 90% and …
