Atmospheric Sciences Commons^™

Oh And Oi Airglow Layer Modulation By Ducted Short-Period Gravity Waves: Effects Of Trapping Altitude, Jonathan B. Snively, Victor P. Pasko, Michael J. Taylor

Publications

Perturbations to the OH and OI [O(1S) 557.7 nm] airglow layers by ducted gravity waves near the Brunt‐Väisälä period are investigated using a 2‐D numerical model. Airglow signatures of these waves are strongly determined by perturbations of O, O3, and H, which exhibit peak densities near and above mesopause. Strong periodic vertical wind components of short‐period gravity waves induce opposite relative density perturbations above and below the layer density peaks. Airglow signatures for ducted waves depend on the specific vertical shapes and altitudes of the wave packets relative to ambient species density profiles; waves perturbing only the bottoms or tops …

A New Interpretation Of Total Column Bro During Arctic Spring, R J. Salawitch, T Canty, T P. Kurosu, K Chance, Q Liang, Arlindo Da Silva, S Pawson, J E. Neilsen, J. V. Rodriguez, P K. Bhartia, X Liu, L Gregory Huey, J Liao, R E. Stickel, D Tanner, Jack E. Dibb, W R. Simpson, D Donohue, Andrew Weinheimer, F Flocke, D Knapp, D Montzka, J A. Neuman, J Nowak, Thomas B. Ryerson, S J. Oltmans, D R. Blake, E L. Atlas, D Kinnison, S Tilmes, L L. Pan, F Hendrick, R Bradley Pierce, M Van Roozendael, K Kreher, P V. Johnston, R S. Gao, B Johnson, T P. Bui, G Chen, R B. Pierce, J H. Crawford, D J. Jacob

Earth Sciences

Emission of bromine from sea-salt aerosol, frost flowers, ice leads, and snow results in the nearly complete removal of surface ozone during Arctic spring. Regions of enhanced total column BrO observed by satellites have traditionally been associated with these emissions. However, airborne measurements of BrO and O₃ within the convective boundary layer (CBL) during the ARCTAS and ARCPAC field campaigns at times bear little relation to enhanced column BrO. We show that the locations of numerous satellite BrO “hotspots” during Arctic spring are consistent with observations of total column ozone and tropopause height, suggesting a stratospheric origin to these …

Characterization Of Pollen Particles Using Lidar, Leda Sox

Graduate Student Posters

We have observed pollen in the local troposphere using the depolarization capabilities of a LIDAR (Light Detection and Ranging) system. The polarization characteristics of the received LIDAR signal, along with supplemental pollen forecast data, allowed me to characterize the shape of the pollen particles.

Bromide And Other Ions In The Snow, Firn Air, And Atmospheric Boundary Layer At Summit During Gshox, Jack E. Dibb, Luke D. Ziemba, J Luxford, P Beckman

Earth Sciences

Measurements of gas phase soluble bromide in the boundary layer and in firn air, and Br⁻ in aerosol and snow, were made at Summit, Greenland (72.5° N, 38.4° W, 3200 m a.s.l.) as part of a larger investigation into the influence of Br chemistry on HO_x cycling. The soluble bromide measurements confirm that photochemical activation of Br⁻ in the snow causes release of active Br to the overlying air despite trace concentrations of Br⁻ in the snow (means 15 and 8 nmol Br⁻ kg⁻¹ of snow in 2007 and 2008, respectively). Mixing ratios of …

The First Ten Months Of Investigation Of Gravity Waves And Temperature Variability Over The Andes, Jonathan Pugmire, Neal Criddle, Michael J. Taylor, P. D. Pautet, Yucheng Zhao

Graduate Student Posters

The Andes region is an excellent natural laboratory for investigating gravity wave influences on the Upper Mesospheric and Lower Thermospheric (MLT) dynamics. The instrument suite that comprised the very successful Maui-MALT program was recently re-located to a new Andes Lidar Observatory (ALO) located at Cerro Pachon, Chile to obtain in-depth seasonal measurements of MLT dynamics over the Andes mountains. As part of the instrument set the Utah State University CEDAR Mesospheric Temperature Mapper (MTM) has operated continuously since August 2009 measuring the near infrared OH(6,2) band and the O2(0,1) Atmospheric band intensity and temperature perturbations. This poster focuses on an …

First Year Investigation Of Gravity Waves And Temperature Variability Over The Andes, Jonathan Pugmire, Neal R. Criddle, Michael J. Taylor, Dominique Pautet, Yucheng Zhao

Graduate Student Presentations

The Andes region is an excellent natural laboratory for investigating gravity wave influences on the Upper Mesospheric and Lower Thermospheric (MLT) dynamics: during the summer months the dominant gravity waves result from deep convection arising from severe thunderstorms over the continent to the east. In winter this convective activity is expected to be replaced by strong orographic forcing due to intense prevailing zonal winds blowing eastward from the Pacific Ocean and suddenly encountering the towering Andes mountain range (6000m). This creates large amplitude mountain waves that have been measured well into the stratosphere and most recently penetrate occasionally into the …

Chemistry–Climate Model Simulations Of Twenty-First Century Stratospheric Climate And Circulation Changes, Neal Butchart, I. Cionni, V. Eyring, T. G. Shepherd, D. W. Waugh, H. Akiyoshi, J. Austin, C. Brühl, M. P. Chipperfield, Eugene C. Cordero, M. Dameris, R. Deckert, S. Dhomse, S. M. Frith, R. R. Garcia, A. Gettelman, M. A. Giorgetta, D. E. Kinnison, F. Li, E. Mancini, S. Pawson, G. Pitari, D. A. Plummer, E. Rozanov, F. Sassi, J. F. Scinocca, K. Shibata, B. Steil, W. Tian

Faculty Publications, Meteorology and Climate Science

The response of stratospheric climate and circulation to increasing amounts of greenhouse gases (GHGs) and ozone recovery in the twenty-first century is analyzed in simulations of 11 chemistry–climate models using near-identical forcings and experimental setup. In addition to an overall global cooling of the stratosphere in the simulations (0.59 ± 0.07 K decade⁻¹ at 10 hPa), ozone recovery causes a warming of the Southern Hemisphere polar lower stratosphere in summer with enhanced cooling above. The rate of warming correlates with the rate of ozone recovery projected by the models and, on average, changes from 0.8 to 0.48 K decade …

Droughtscape, Fall 2010, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

CDC Issues Drought Guidance for Public Health

La Niña May Intensify Drought in South

Recent Workshops and Meetings

East Feels Impacts as Heat Intensifies Drought

New Products

Nicole Wall Co-Facilitates Republican River Basin Task Force

NDMC Climatologist on Ethiopia Team

A Three-Year Study Of The Magnetic Field Fluctuations In The Magnetospheric Cusp, Christina Seiman Chu

Master's Theses - Daytona Beach

The high-altitude magnetospheric cusps are regions of significant magnetic field turbulence. There are also magnetic field fluctuations that cannot be called turbulence. Some of the low frequency fluctuations observed in the cusp have been shown to be motion of the cusp structure by the spacecraft (back and forth motion of the boundaries surrounding the cusp); others are transient reconnection signatures or flux transfer events (FTEs). Turbulence is important to understand because it has been proposed as a mechanism for particle energization in the cusps to MeV levels. High resolution magnetic field data from the Fluxgate Magnetometer instruments on the Cluster …

Extensive Aerosol Optical Properties And Aerosol Mass Related Measurements During Tramp/Texaqs 2006 – Implications For Pm Compliance And Planning, Monica Elizabeth Wright, Dean B. Atkinson, Luke Ziemba, Robert Griffin, Naruki Hiranuma, Sarah D. Brooks, James Flynn, Ryan Perna, Bernhard Rappenglück, Winston Luke, Paul Kelley

Chemistry Faculty Publications and Presentations

Extensive aerosol optical properties, particle size distributions, and Aerodyne quadrupole aerosol mass spectrometer measurements collected during TRAMP/TexAQS 2006 were examined in light of collocated meteorological and chemical measurements. Much of the evident variability in the observed aerosol-related air quality is due to changing synoptic meteorological situations that direct emissions from various sources to the TRAMP site near the center of the Houston-Galveston-Brazoria (HGB) metropolitan area. In this study, five distinct long-term periods have been identified. During each of these periods, observed aerosol properties have implications that are of interest to environmental quality management agencies. During three of the periods, long …

Determining The Index Of Refraction Of An Unknown Object Using Passive Polarimetric Imagery Degraded By Atmospheric Turbulence, Milo W. Hyde Iv

Theses and Dissertations

In this research, an algorithm is developed to estimate the index of refraction of an unknown object using passive polarimetric images degraded by atmospheric turbulence. The algorithm uses a variant of the maximum-likelihood blind-deconvolution algorithm developed by LeMaster and Cain to recover the true object (i.e., the first Stokes parameter), the degree of linear polarization, and the polarimetric-image point spread functions. Nonlinear least squares is then used to find the value of the complex index of refraction which best fits the theoretical degree of linear polarization, derived using a polarimetric bidirectional reflectance distribution function, to the turbulence-corrected degree of linear …

Release Of Mercury Halides From Kcl Denuders In The Presence Of Ozone, Seth N. Lyman, Daniel A. Jaffe, Mae S. Gustin

USU Uintah Basin Faculty Publications

KCl-coated denuders have become a standard method for measurement of gaseous oxidized mercury, but their performance has not been exhaustively evaluated, especially in field conditions. In this study, KCl-coated and uncoated quartz denuders loaded with HgCl₂ and HgBr₂ lost 29–55% of these compounds, apparently as elemental mercury, when exposed to ozone (range of 6–100 ppb tested). This effect was also observed for denuders loaded with gaseous oxidized mercury at a field site in Nevada (3–37% of oxidized mercury lost). In addition, collection efficiency decreased by 12–30% for denuders exposed to 50 ppb ozone during collection of HgCl_{2 …}

Developing Tornado Climatology In The Southern Great Plains Per Phases Of Prominent Oceanic Oscillations, Nicholas M. Fillo

Geography and the Environment: Graduate Student Capstones

Meteorologists are continually working toward a greater understanding of which atmospheric environments are most conducive for tornado development. This Capstone project analyzed tornado occurrences across Texas, Oklahoma, Arkansas and Louisiana during the period 1950 through 2009 to determine if any correlation exists between the location and frequency of tornado activity and the phases of the El Nino-Southern Oscillation, the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation. While it was determined that no phase of any of the oscillations studied was significantly more dominant over the other(s) concerning frequency, this project does identify some spatial shifts in tornado activity depending …

The Production And Persistence Of Σrono2 In The Mexico City Plume, A E. Perring, T H. Bertram, D K. Farmer, Paul J. Wooldridge, Jack E. Dibb, N J. Blake, D R. Blake, H B. Singh, H Fuelberg, Glenn Diskin, G W. Sachse, Robert C. Cohen

Earth Sciences

Alkyl and multifunctional nitrates (RONO₂, ΣANs) have been observed to be a significant fraction of NO_y in a number of different chemical regimes. Their formation is an important free radical chain termination step ending production of ozone and possibly affecting formation of secondary organic aerosol. ΣANs also represent a potentially large, unmeasured contribution to OH reactivity and are a major pathway for the removal of nitrogen oxides from the atmosphere. Numerous studies have investigated the role of nitrate formation from biogenic compounds and in the remote atmosphere. Less attention has been paid to the role ΣANs may …

Wind Flow Modeling For Wind Energy Analysis Of The Nellis Dunes Area In Nevada, Upendra Rangegowda

UNLV Theses, Dissertations, Professional Papers, and Capstones

A wind energy analysis of the Nellis Dunes area in Nevada was conducted. A DEM file which contains the elevation data was used to generate the surface model and to create a 3-D mesh of the region. Local meteorological tower data collected for a period of one year was used to generate the diagnostic initial wind fields. Upper level wind fields were created using a surface boundary layer technique along with linear interpolation of the tower level wind fields. The vertical components of the velocities were adjusted using the equation of continuity. Mass consistent 3-D wind fields were then calculated …

Synthesis Of Satellite (Modis), Aircraft (Icartt), And Surface (Improve, Epa-Aqs, Aeronet) Aerosol Observations Over Eastern North America To Improve Modis Aerosol Retrievals And Constrain Surface Aerosol Concentrations And Sources, Easan Drury, Daniel J. Jacob, Robert J.D. Spurr, Jun Wang, Yohei Shinozuka, Bruce E. Anderson, A D. Clarke, Jack E. Dibb, Cameron Mcnaughton, Rodney J. Weber

Earth Sciences

We use an ensemble of satellite (MODIS), aircraft, and ground-based aerosol observations during the ICARTT field campaign over eastern North America in summer 2004 to (1) examine the consistency between different aerosol measurements, (2) evaluate a new retrieval of aerosol optical depths (AODs) and inferred surface aerosol concentrations (PM_2.5) from the MODIS satellite instrument, and (3) apply this collective information to improve our understanding of aerosol sources. The GEOS-Chem global chemical transport model (CTM) provides a transfer platform between the different data sets, allowing us to evaluate the consistency between different aerosol parameters observed at different times and …

Droughtscape, Summer 2010, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Upcoming Workshops

Mild Drought Season Likely to Persist

Drought Impacts Intensify in Upper Midwest

Visiting Scientists

North Carolina Takes Drought Monitor Seriously

International Work- Murcia, Spain, June

A Differential Absorption Model For Remote Sensing Of Atmospheric Pressure, Shivam J. Shah

Electrical & Computer Engineering Theses & Dissertations

The goal of the project is to develop and test a "model based" radar processing strategy that is compatible with the concept of a "cognitive radar". The basic approach will be to develop a cognitive radar algorithm (genetic algorithm) based on the capabilities of an existing commercially available Software Radio. While the focus of this effort is the development of a candidate approach for genetic algorithm, the longer term goal would be to implement the approach using this software radio technology to provide a low cost radar processor. The proposed technology would use differential absorption radar working at the 50-56 …

Realistic Vertical Atmospheric Profiles And Effects From Limited Surface Observations, Dane P. Ranney

Theses and Dissertations

The ability to accurately describe the atmospheric conditions around us is not only important to the Air Force, but to anyone involved in signal propagation. The programs currently utilized to describe the atmosphere take into account a variety of measures. The LEEDR (Laser Environmental Effects Definition and Reference) program in particular, allows the user to select a location, aerosol and molecular effects model, numerous cloud and precipitation events, as well as other features. Even with the control that the user has, the output that the program provides can vary from actual conditions on a day to day basis. This is …

Atmospheric Airglow Fluctuations Due To A Tsunami‐Driven Gravity Wave Disturbance, Michael P. Hickey Ph.D., G. Schubert, R. L. Walterscheid

Publications

A spectral full‐wave model is used to study the upward propagation of a gravity wave disturbance and its effect on atmospheric nightglow emissions. Gravity waves are generated by a surface displacement that mimics a tsunami having a maximum amplitude of 0.5 m, a characteristic horizontal wavelength of 400 km, and a horizontal phase speed of 200 m/s. The gravity wave disturbance can reach F region altitudes before significant viscous dissipation occurs. The response of the OH Meinel nightglow in the mesopause region (∼87 km altitude) produces relative brightness fluctuations, which are ∼1% of the mean for overhead viewing. The wave …