Atmospheric Sciences Commons^™

Propagating And Non-Propagating Intraseasonal Oscillations In The Tropical Atmosphere: Their Vertical And Horizontal Structures And Developing Mechanisms, Zhaoning Liang

School of Natural Resources: Dissertations, Theses, and Student Research

A fixed beamformer is proposed and designed to identify source regions of Intra-Seasonal Oscillations (ISO) in the tropical atmosphere. After tested by simulations of single and complex sources of waves, the fixed beamformer is applied to the ECMWF interpolated data grids to detect and identify source regions of the ISO in the tropical Indian and Pacific Ocean region. Results show that the fixed beamforming technique can uniquely identify the source region of the ISO, the source regions of all major ISO in the tropical Indian and western equatorial Pacific region from 1974 to 2002 have been identified.

Examinations of ISO …

Statistical Analysis Of The Usu Lidar Data Set With Reference To Mesospheric Solar Response And Cooling Rate Calculation, With Analysis Of Statistical Issues Affecting The Regression Coefficients, Troy Alden Wynn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Though the least squares technique has many advantages, its possible limitations as applied in the atmospheric sciences have not yet been fully explored in the literature. The assumption that the atmosphere responds either in phase or out of phase to the solar input is ubiquitous. However, our analysis found this assumption to be incorrect. If not properly addressed, the possible consequences are bias in the linear trend coefficient and attenuation of the solar response coefficient.

Using USU Rayleigh lidar temperature data, we found a significant phase offset to the solar input in the temperatures that varies ±5 years depending on …

Architecture, Modeling, And Analysis Of A Plasma Impedance Probe, Magathi Jayaram

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Variations in ionospheric plasma density can cause large amplitude and phase changes in the radio waves passing through this region. Ionospheric weather can have detrimental effects on several communication systems, including radars, navigation systems such as the Global Positioning Sytem (GPS), and high-frequency communications. As a result, creating models of the ionospheric density is of paramount interest to scientists working in the field of satellite communication.

Numerous empirical and theoretical models have been developed to study the upper atmosphere climatology and weather. Multiple measurements of plasma density over a region are of marked importance while creating these models. The lack …

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 …

Attribution Of Spatial And Temporal Variations In Terrestrial Methane Flux Over North America, X. F. Xu, Hanqin Tian, C. Zhang, M. L. Liu, Wei Ren, G. S. Chen, Chaoqun (Crystal) Lu, L. Bruhwiler

Chaoqun (Crystal) Lu

The attribution of spatial and temporal variations in terrestrial methane (CH4) flux is essential for assessing and mitigating CH4 emission from terrestrial ecosystems. In this study, we used a process-based model, the Dynamic Land Ecosystem Model (DLEM), in conjunction with spatial data of six major environmental factors to attribute the spatial and temporal variations in the terrestrial methane (CH4) flux over North America from 1979 to 2008 to six individual driving factors and their interaction. Over the past three decades, our simulations indicate that global change factors accumulatively contributed 23.51 ± 9.61 T g CH4-C (1 Tg = 1012 g) …

Characterization Of Pollen Particles Using Lidar, Leda Sox

Leda Sox

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.

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 …

Wave-Induced Transport Of Atmospheric Constituents And Its Effect On The Mesospheric Na Layer, Chester S. Gardner, Alan Z. Liu

Alan Z Liu

No abstract provided.

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 NDMC, 2007-

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

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

Eugene C. Cordero

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 …

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 …}

Spatial And Temporal Patterns Of Ch4 And N2o Fluxes In Terrestrial Ecosystems Of North America During 1979–2008: Application Of A Global Biogeochemistry Model, Hanqin Tian, X. Xu, M. Liu, Wei Ren, C. Zhang, G. Chen, Chaoqun (Crystal) Lu

Chaoqun (Crystal) Lu

Continental-scale estimations of terrestrial methane (CH4) and nitrous oxide (N2O) fluxes over a long time period are crucial to accurately assess the global balance of greenhouse gases and enhance our understanding and prediction of global climate change and terrestrial ecosystem feedbacks. Using a process-based global biogeochemical model, the Dynamic Land Ecosystem Model (DLEM), we quantified simultaneously CH4 and N2O fluxes in North America's terrestrial ecosystems from 1979 to 2008. During the past 30 years, approximately 14.69 ± 1.64 T g C a−1 (1 T g = 1012 g) of CH4, and 1.94 ± 0.1 T g N a−1 of N2O …

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 …

全球变化与陆地系统综合集成模拟 ——新一代陆地生态系统动态模型 (Dlem), 汉勤 田, 明亮 刘, 弛 张, 巍 任, 小锋 徐, 广生 陈, 超群 吕, 波 陶

Chaoqun (Crystal) Lu

人类社会从陆地生态系统获取生产和生活资料的同时也作为一种干扰形式改变着地气之间的动态平衡。这三个既独立又相互耦合的子系统共同组成了一个复杂的陆地系统。如何深入理解这一系统的过程和机制是人类应对气候变化挑战的前提条件。陆地生态系统模型作为一种集成工具，已广泛应用于全球变化研究的各个领域，但从输入数据到模型结构和过程等诸多方面仍存在很大的不确定性。近年来，随着大气和地面生态观测网络的不断完善以及遥感等空间技术的不断强大，使陆地生态系统模型进一步发展和突破成为可能。新一代多因子驱动的陆地生态系统动态模型(Dynamic Land Ecosystem Model, DLEM) 正是在这一背景下 应运而生的。本文旨在介绍DLEM的主体框架、输入输出变量、关键过程、主要功能和特点。

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 NDMC, 2007-

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

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 …

The Arctic Research Of The Composition Of The Troposphere From Aircraft And Satellites (Arctas) Mission: Design, Execution, And First Results, D J. Jacob, J H. Crawford, H Maring, A D. Clarke, Jack E. Dibb, L K. Emmons, R A. Ferrare, C A. Hostetler, Phil Russell, H B. Singh, A M. Thompson, G E. Shaw, E Mccauley, Judith Pederson, Jenny Fisher

Earth Sciences

The NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was conducted in two 3-week deployments based in Alaska (April 2008) and western Canada (June–July 2008). Its goal was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1) influx of mid-latitude pollution, (2) boreal forest fires, (3) aerosol radiative forcing, and (4) chemical processes. The June–July deployment was preceded by one week of flights over California (ARCTAS-CARB) focused on (1) improving state emission inventories for greenhouse gases and aerosols, (2) providing observations to test and improve models …

Measurement And Interpolation Of Sea Surface Temperature And Salinity In The Tropical Pacific: A 9,000 Nautical Mile Research Odyssey, Amber Brooks

Earth and Soil Sciences

The purpose of this project was to compare spline and inverse distance weighting interpolation tools on data collected in the tropical Pacific Ocean by ship and data from a global network of CTD floats, known as Argo floats (fig.1), to provide evidence that technological advancement and integration is aiding our understanding of the ocean-atmosphere system of planet Earth. Thirty-one sea surface temperature and salinity samples were manually taken across a 9,000 nautical mile trek of the Pacific Ocean for the months of April, May and June 2008. Argo ASCII globally gridded monthly averaged sea surface temperature and salinity data, from …

Convective Distribution Of Tropospheric Ozone And Tracers In The Central American Itcz Region: Evidence From Observations During Tc4, M A. Avery, Cynthia Twohy, David Mccabe, J Joiner, Kurt Severance, E L. Atlas, D R. Blake, T P. Bui, John D. Crounse, Jack E. Dibb, Glenn Diskin, Paul Lawson, Matthew Mcgill, David Rogers, G W. Sachse, Eric Scheuer, A M. Thompson, Charles Trepte, Paul Wennberg, Jerald Ziemke

Earth Sciences

During the Tropical Composition, Clouds and Climate Coupling (TC4) experiment that occurred in July and August of 2007, extensive sampling of active convection in the ITCZ region near Central America was performed from multiple aircraft and satellite sensors. As part of a sampling strategy designed to study cloud processes, the NASA ER‐2, WB‐57 and DC‐8 flew in stacked “racetrack patterns” in convective cells. On July 24, 2007, the ER‐2 and DC‐8 probed an actively developing storm and the DC‐8 was hit by lightning. Case studies of this flight, and of convective outflow on August 5, 2007 reveal a significant anti‐correlation …

Evidence Of Nitric Acid Uptake In Warm Cirrus Anvil Clouds During The Nasa Tc4 Campaign, Eric Scheuer, Jack E. Dibb, Cynthia Twohy, David Rogers, Andrew J. Heymsfield, Aaron Bansemer

Earth Sciences

Uptake of HNO3 onto cirrus ice may play an important role in tropospheric NOx cycling. Discrepancies between modeled and in situ measurements of gas-phase HNO3 in the troposphere suggest that redistribution and removal mechanisms by cirrus ice have been poorly constrained. Limited in situ measurements have provided somewhat differing results and are not fully compatible with theory developed from laboratory studies. We present new airborne measurements of HNO3 in cirrus clouds from anvil outflow made during the Tropical Composition, Cloud, and Climate Coupling Experiment (TC4). Upper tropospheric (>9 km) measurements made during three flights while repeatedly traversing the same …