Oceanography and Atmospheric Sciences and Meteorology Commons^™

Chemical Data Assimilation Estimates Of Continental U.S. Ozone And Nitrogen Budgets During The Intercontinental Chemical Transport Experiment-North America, R B. Pierce, T Schaack, J Al-Saadi, T D. Fairlie, Chieko Kittaka, Gretchen Lingenfelser, M Natarajan, J R. Olson, Amber Soja, Tom Zapotocny, A Lenzen, M A. Avery, James Stobie, Donald Johnson, Melody A. Avery, G W. Sachse, A M. Thompson, Ronald C. Cohen, Jack E. Dibb, J Crawford, Didier Rault, Randall Martin, Jim Szykman, Jack Fishman

Earth Sciences

Global ozone analyses, based on assimilation of stratospheric profile and ozone column measurements, and NOy predictions from the Real-time Air Quality Modeling System (RAQMS) are used to estimate the ozone and NOy budget over the continental United States during the July-August 2004 Intercontinental Chemical Transport Experiment-North America (INTEX-A). Comparison with aircraft, satellite, surface, and ozonesonde measurements collected during INTEX-A show that RAQMS captures the main features of the global and continental U.S. distribution of tropospheric ozone, carbon monoxide, and NOy with reasonable fidelity. Assimilation of stratospheric profile and column ozone measurements is shown to have a positive impact on the …

Improving Regional Ozone Modeling Through Systematic Evaluation Of Errors Using The Aircraft Observations During The International Consortium For Atmospheric Research On Transport And Transformation, M Mena-Carrasco, Youhua Tang, Gregory R. Carmichael, Tianfeng Chai, Narisara Thongbongchoo, J Elliott Campbell, S Kulkarni, Larry Horowitz, Jeffrey Vukovich, Melody A. Avery, William H. Brune, Jack E. Dibb, L K. Emmons, F Flocke, Glen Sachse, David Tan, R E. Shetter, R. Talbot, David G. Streets, D R. Blake

Earth Sciences

During the operational phase of the ICARTT field experiment in 2004, the regional air quality model STEM showed a strong positive surface bias and a negative upper troposphere bias (compared to observed DC-8 and WP-3 observations) with respect to ozone. After updating emissions from NEI 1999 to NEI 2001 (with a 2004 large point sources inventory update), and modifying boundary conditions, low-level model bias decreases from 11.21 to 1.45 ppbv for the NASA DC-8 observations and from 8.26 to −0.34 for the NOAA WP-3. Improvements in boundary conditions provided by global models decrease the upper troposphere negative ozone bias, while …

Reactive Nitrogen Distribution And Partitioning In The North American Troposphere And Lowermost Stratosphere, H B. Singh, L Salas, D Herlth, R Koyler, M A. Avery, J H. Crawford, R B. Pierce, Glen Sachse, D R. Blake, Ronald C. Cohen, T H. Bertram, A E. Perring, Paul J. Wooldridge, Jack E. Dibb, L Gregory Huey, R C. Hudman, S Turquety, L K. Emmons, F Flocke, Youhua Tang, Gregory R. Carmichael, Larry Horowitz

Earth Sciences

A comprehensive group of reactive nitrogen species (NO, NO₂, HNO₃, HO₂NO₂, PANs, alkyl nitrates, and aerosol-NO₃⁻) were measured over North America during July/August 2004 from the NASA DC-8 platform (0.1–12 km). Nitrogen containing tracers of biomass combustion (HCN and CH₃CN) were also measured along with a host of other gaseous (CO, VOC, OVOC, halocarbon) and aerosol tracers. Clean background air as well as air with influences from biogenic emissions, anthropogenic pollution, biomass combustion, convection, lightning, and the stratosphere was sampled over the continental United States, the Atlantic, …

Summertime Influence Of Asian Pollution In The Free Troposphere Over North America, Q Liang, L Jaegle, R C. Hudman, S Turquety, D J. Jacob, Melody A. Avery, E V. Browell, G W. Sachse, D R. Blake, William H. Brune, Xinrong Ren, Ronald C. Cohen, Jack E. Dibb, A Fried, H Fuelberg, M Porter, B J. Heikes, Greg Huey, H B. Singh, Paul Wennberg

Earth Sciences

We analyze aircraft observations obtained during INTEX-A (1 July to 14 August 2004) to examine the summertime influence of Asian pollution in the free troposphere over North America. By applying correlation analysis and principal component analysis (PCA) to the observations between 6 and 12 km, we find dominant influences from recent convection and lightning (13% of observations), Asia (7%), the lower stratosphere (7%), and boreal forest fires (2%), with the remaining 71% assigned to background. Asian air masses are marked by high levels of CO, O3, HCN, PAN, C2H2, C6H6, methanol, and SO4 2 –. The partitioning of NOy species …

Biomass Burning And Pollution Aerosol Over North America: Organic Components And Their Influence On Spectral Optical Properties And Humidification Response, A D. Clarke, Cameron Mcnaughton, V Kapustin, Yohei Shinozuka, S G. Howell, Jack E. Dibb, J Zhou, B Anderson, V Brekhovskikh, H Turner, M Pinkerton

Earth Sciences

Thermal analysis of aerosol size distributions provided size resolved volatility up to temperatures of 400°C during extensive flights over North America (NA) for the INTEX/ICARTT experiment in summer 2004. Biomass burning and pollution plumes identified from trace gas measurements were evaluated for their aerosol physiochemical and optical signatures. Measurements of soluble ionic mass and refractory black carbon (BC) mass, inferred from light absorption, were combined with volatility to identify organic carbon at 400°C (VolatileOC) and the residual or refractory organic carbon, RefractoryOC. This approach characterized distinct constituent mass fractions present in biomass burning and pollution plumes every 5–10 min. Biomass …

Surface And Lightning Sources Of Nitrogen Oxides Over The United States: Magnitudes, Chemical Evolution, And Outflow, R C. Hudman, D J. Jacob, S Turquety, Eric M. Leibensperger, L T. Murray, S Wu, A B. Gilliland, M A. Avery, T H. Bertram, William H. Brune, Ronald C. Cohen, Jack E. Dibb, F Flocke, A Fried, J S. Holloway, J A. Neuman, R Orville, A E. Perring, Xinrong Ren, G W. Sachse, H B. Singh, Aaron L. Swanson, Paul J. Wooldridge

Earth Sciences

We use observations from two aircraft during the ICARTT campaign over the eastern United States and North Atlantic during summer 2004, interpreted with a global 3-D model of tropospheric chemistry (GEOS-Chem) to test current understanding of regional sources, chemical evolution, and export of NOx. The boundary layer NOx data provide top-down verification of a 50% decrease in power plant and industry NOx emissions over the eastern United States between 1999 and 2004. Observed NOx concentrations at 8–12 km altitude were 0.55 ± 0.36 ppbv, much larger than in previous U.S. aircraft campaigns (ELCHEM, SUCCESS, SONEX) though consistent with data from …

Numerical Modeling Of A Gravity Wave Packet Ducted By The Thermal Structure Of The Atmosphere, Yonghui Yu, Michael P. Hickey Ph.D.

Publications

A time-dependent and fully nonlinear numerical model is employed to solve the Navier-Stokes equations in two spatial dimensions and to describe the propagation of a Gaussian gravity wave packet generated in the troposphere. A Fourier spectral analysis is used to analyze the frequency power spectra of the wave packet, which propagates through and dwells within several thermal ducting regions. The frequency power spectra of the wave packet are derived at several discrete altitudes, which allow us to determine the evolution of the packet. This spectral analysis also clearly reveals the existence of a stratospheric duct, a mesospheric and lower thermospheric …

Simulated Ducting Of High-Frequency Atmospheric Gravity Waves In The Presence Of Background Winds, Yonghui Yu, Michael P. Hickey Ph.D.

Publications

A new nonlinear and time-dependent model is used to derive the total perturbation energy flux of two gravity wave packets propagating from the troposphere to the lower thermosphere. They are excited by a heat source and respectively propagate in an eastward and westward direction in the presence of a zonal wind. Analysis of the refractive index, the power spectra and the total perturbation energy flux allows us to correctly interpret the ducting characteristics of these two wave packets. In our study the wind acts as a directional filter to the wave propagations and causes noticeable spectral variations at higher altitudes. …

Influence Of Lateral And Top Boundary Conditions On Regional Air Quality Prediction: A Multiscale Study Coupling Regional And Global Chemical Transport Models, Youhua Tang, Gregory R. Carmichael, Narisara Thongbongchoo, Tianfeng Chai, Larry Horowitz, R B. Pierce, J Al-Saadi, G G. Pfister, Jeffrey Vukovich, Melody A. Avery, Glen Sachse, Thomas B. Ryerson, J S. Holloway, E L. Atlas, F Flocke, Rodney J. Weber, L Gregory Huey, Jack E. Dibb, David G. Streets, William H. Brune

Earth Sciences

The sensitivity of regional air quality model to various lateral and top boundary conditions is studied at 2 scales: a 60 km domain covering the whole USA and a 12 km domain over northeastern USA. Three global models (MOZART-NCAR, MOZART-GFDL and RAQMS) are used to drive the STEM-2K3 regional model with time-varied lateral and top boundary conditions (BCs). The regional simulations with different global BCs are examined using ICARTT aircraft measurements performed in the summer of 2004, and the simulations are shown to be sensitive to the boundary conditions from the global models, especially for relatively long-lived species, like CO …

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Doppler Ducting Of Short-Period Gravity Waves By Midaltitude Tidal Wind Structure, Jonathan B. Snively, Victor P. Pasko, Michael J. Taylor, Wayne K. Hocking

Publications

Multiwavelength airglow image data depicting a short-period (∼4.9 min) atmospheric gravity wave characterized by a sharp leading front have been analyzed together with synoptic meteor radar wind data recorded simultaneously from Bear Lake Observatory, Utah (41.6°N, 111.6°W). The wind data suggest the presence of a semidiurnal tide with horizontal winds peaking at around 60 m/s along the SSE direction of motion (170° from north) of this short-period wave. It was found that the gravity wave was most probably ducted because of the Doppler shift imposed by this wind structure. A marked 180° phase shift was observed between the near-infrared OH …

Holes: Ionospheric Scintillation, Gps And Imputation, Robert A. Steenburgh

Theses and Dissertations

Ionospheric scintillation of Global Positioning System (GPS) signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active, although not limited to, a belt encircling the earth within ± 20 degrees of the geomagnetic equator. This belt also hosted roughly half of the completed U.S. military operations in the last decade. The authors examined scintillation data from Ascension Island, United Kingdom, and Ancon, Peru, in the Atlantic longitudinal sector as well as data from Parepare, Indonesia, and Marak Parak, Malaysia, in the Pacific longitudinal sector. From these data, they calculate percent probability of occurrence …

Assessment Of The Impact Of Various Ionospheric Models On High Frequency Signal Raytracing, Joshua T. Werner

Theses and Dissertations

An assessment of the impact of various ionospheric models on high-frequency (HF) signal raytracing is presented. Ionospheric refraction can strongly affect the propagation of HF signals. Consequently, Department of Defense missions such as over-the-horizon RADAR, HF communications, and geo-location all depend on an accurate specification of the ionosphere. Five case studies explore ionospheric conditions ranging from quiet conditions to solar flares and geomagnetic storms. It is shown that an E layer by itself can increase an HF signal’s ground range by over 100 km, stressing the importance of accurately specifying the lower ionosphere. It is also shown that the GPSII …

Anisotropy In The South Atlantic Anomaly, Shaun M. Easley

Theses and Dissertations

From June 2000 through July 2006, the TSX-5 satellite measured proton fluxes in the Earth’s magnetosphere using its CEASE instrument. A review of the satellite data by scientists at AFRL/VSBX revealed an unanticipated, recurring bi-modal structure in histograms of the proton counts. This research identified the bi-modal behavior as anisotropic in nature, and the result of two separate processes. At low altitudes the anisotropy was well described by the classic “East-West Effect.” Comparisons of the satellite data to simple analytical models are presented. At high altitudes, the anisotropy was the result of the detector measuring protons at different pitch angles …

Assessment Of Optical Turbulence Profiles Derived From Probabilistic Climatology, Brett W. Wisdom

Theses and Dissertations

This research effort assesses the performance of the High Energy Laser End-to-End Operational Simulation (HELEEOS) Climatological C²_n optical turbulence model. Path-integrated C²_n values of two HELEEOS optical turbulence pro les at 3 distinct operational altitudes are compared to values determined from measured thermosonde data. HELEEOS desert and mid-latitude sites are selected from the Extreme and Percentile Environmental Reference Tables (ExPERT) database for comparison to the thermosonde data. Statistical equivalence of the two datasets is determined through a Design of Experiments (DOE) factorial test to within 80% confidence. The HELEEOS profiles are shown to be equivalent to …

The Green Beam—Lidar Investigations Of The Mesosphere, Vincent B. Wickwar

Presentations

No abstract provided.

Modeling, Simulation, And Estimation Of Optical Turbulence, Byron P. Formwalt

Theses and Dissertations

This dissertation documents three new contributions to simulation and modeling of optical turbulence. The first contribution is the formalization, optimization, and validation of a modeling technique called successively conditioned rendering (SCR). The SCR technique is empirically validated by comparing the statistical error of random phase screens generated with the technique. The second contribution is the derivation of the covariance delineation theorem, which provides theoretical bounds on the error associated with SCR. It is shown empirically that the theoretical bound may be used to predict relative algorithm performance. Therefore, the covariance delineation theorem is a powerful tool for optimizing SCR algorithms. …

Estimation Of Dry Deposition Of Atmospheric Mercury In Nevada By Direct And Indirect Methods, Seth N. Lyman, Mae Sexauer Gustin, Eric M. Prestbo, Frank J. Marsik

USU Uintah Basin Faculty Publications

Atmospheric models and limited measurements indicate that dry deposition of atmospheric mercury is an important process by which mercury is input to ecosystems. To begin to fill the measurement data gap, multiple methods were used simultaneously during seasonal campaigns conducted in 2005 and 2006 to estimate dry deposition of atmospheric mercury at two Mercury Deposition Network (MDN) sites in rural Nevada and in Reno, Nevada. Gaseous elemental mercury (Hg0), reactive gaseous mercury (RGM), and particulate-bound mercury (Hgp) concentrations were measured using Tekran 2537A/1130/1135 systems. These speciated measurements were combined with on-site meteorological measurements to estimate depositional fluxes of RGM and …

Time-Resolved Ducting Of Atmospheric Acoustic-Gravity Waves By Analysis Of The Vertical Energy Flux, Yonghui Yu, Michael P. Hickey Ph.D.

Publications

A new 2-D time-dependent model is used to simulate the propagation of an acoustic-gravity wave packet in the atmosphere. A Gaussian tropospheric heat source is assumed with a forcing period of 6.276 minutes. The atmospheric thermal structure creates three discrete wave ducts in the stratosphere, mesosphere, and lower thermosphere, respectively. The horizontally averaged vertical energy flux is derived over altitude and time in order to examine the time-resolved ducting. This ducting is characterized by alternating upward and downward energy fluxes within a particular duct, which clearly show the reflections occurring from the duct boundaries. These ducting simulations are the first …

Aerosol Major Ion Record At Mount Washington, E V. Fischer, L D. Ziemba, R. Talbot, Jack E. Dibb, Robert J. Griffin, L Husain, A N. Grant

Earth Sciences

This study examined the seasonal cycles and regional-scale meteorological controls on the chemical properties of bulk aerosols collected from 1999 to 2004 at Mount Washington, the highest peak in the northeastern United States. The concentrations of NH₄⁺ and SO₄²⁻ peaked during summer months. The pattern for aerosol NO₃⁻ was more complicated with relatively high median concentrations characterizing spring and summer months, but with major elevated events occurring during fall, winter, and spring. The seasonal relationship between NH₄⁺ and SO₄²⁻ indicated that during warmer months a mixture of (NH₄) …

Chemical And Dynamical Processes In The Mesospheric Emissive Layer. First Results Of Stereoscopic Observations, M. Faivre, G. Moreels, Pierre-Dominique Pautet, J. Clairemidi, F. Dumont, O. Lorin, F. Colas

Publications

[1] The mesospheric emissive layer is an efficient tracer of the dynamical processes propagating in the atmosphere at that level. CCD images in the near infrared taken from the ground at slant angles often reveal the existence of wavy fields. A series of such images has been transformed, using matrix operations, producing a downward satellite-type view that covers a circular area of radius ∼1000 km at the altitude of the layer. The Fourier characteristics of the wave system are measured using a Morlet-type wavelet generator function with horizontal wavelengths of mostly ∼20–40 km and 100–150 km and temporal periods of …

An Ozone-Modified Refractive Index For Vertically Propagating Planetary Waves, Terrence R. Nathan, Eugene C. Cordero

Faculty Publications, Meteorology and Climate Science

[1] An ozone-modified refractive index (OMRI) is derived for vertically propagating planetary waves using a mechanistic model that couples quasigeostrophic potential vorticity and ozone volume mixing ratio. The OMRI clarifies how wave-induced heating due to ozone photochemistry, ozone transport, and Newtonian cooling (NC) combine to affect wave propagation, attenuation, and drag on the zonal mean flow. In the photochemically controlled upper stratosphere, the wave-induced ozone heating (OH) always augments the NC, whereas in the dynamically controlled lower stratosphere, the wave-induced OH may augment or reduce the NC depending on the detailed nature of the wave vertical structure and zonal mean …

Eddy Correlation Measurements Of The Air/Sea Flux Of Dimethylsulfide Over The North Pacific Ocean, Christa A. Marandino, Warren J. De Bruyn, Scott D. Miller, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Shipboard measurements of air/sea fluxes and sea surface concentrations of dimethylsulfide (DMS) were made over the tropical and midlatitude North Pacific Ocean. Atmospheric pressure chemical ionization mass spectrometry was used to measure DMS levels in ambient air and in air equilibrated with surface seawater drawn from a depth of 5 m. Air/sea fluxes were obtained using eddy covariance. Corrections and uncertainties involved in the calculation of fluxes from shipboard data are discussed. The surface ocean DMS concentrations measured during this study ranged from 1 to 10 nM, and atmospheric mixing ratios ranged from 20 to 1000 ppt. Air/sea fluxes ranged …

Light Induced Conversion Of Nitrogen Dioxide Into Nitrous Acid On Submicron Humic Acid Aerosol, K. Stemmler, M. Ndour, Yasin F. Elshorbany, J. Kleffmann, M. Ammann, B. D'Anna, C. George, B. Bohn

USF St. Petersburg Campus Faculty Publications

The interactions of aerosols consisting of humic acids with gaseous nitrogen dioxide (NO2) were investigated under different light conditions in aerosol flow tube experiments at ambient pressure and temperature. The results show that NO2 is converted on the humic acid aerosol into nitrous acid (HONO), which is released from the aerosol and can be detected in the gas phase at the reactor exit. The formation of HONO on the humic acid aerosol is strongly activated by light: In the dark, the HONO-formation was below the detection limit, but it was increasing with the intensity of the irradiation with visible light. …

Observations Of A Noctilucent Cloud Above Logan, Utah (41.7°N, 111.8°W) In 1995, Joshua P. Herron, Vincent B. Wickwar, P J. Espy, J W. Merriwether

All Physics Faculty Publications

A Rayleigh-scatter lidar has been operated at the Atmospheric Lidar Observatory (ALO) on the Utah State University (USU) campus (41.7°N, 111.8°W) since August 1993. During the morning of 22 June 1995, lidar returns from a noctilucent cloud (NLC) were observed for approximately 1 hr, well away from the twilight periods when NLCs are visible. This detection of an NLC at this latitude shows that the first reported sighting, in 1999 (Wickwar et al., 2002), was not a unique occurrence. This 1995 observation differs from the 1999 one in that temperatures could be deduced. Near the 83-km NLC altitude the temperatures …

Particulate Matter Matters!, Storm Project

Open Educational Resources

National Science Education Standards:

• CONTENT STANDARD D: Science as Inquiry
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• CONTENT STANDARD F: Personal and community health; Environmental quality

Agricultural Climatology, Kenneth G. Hubbard

High Plains Regional Climate Center: Staff Publications

With the diversification of the U.S. economy over the past century, agriculture has changed. We can say the farm sizes have increased over time, the number of farmers and those employed in farming have decreased over time, and as the economy has grown the relative contribution of agriculture to the total economy has decreased due to growth in other sectors. The farm prices have not changed significantly over many years while costs for energy, machinery, and land have generally increased. The combination of these factors has generally narrowed the profit margin and the highest productivity will no longer ensure the …

Droughtscape, Winter 2007, Kelly Smith

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

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Simulations Of Phytoplankton Species And Carbon Production In The Equatorial Pacific Ocean 1. Model Configuration And Ecosystem Dynamics, Baris Salihoglu, Eileen E. Hofmann

OES Faculty Publications

The primary objective of this research is to investigate phytoplankton community response to variations in physical forcing and biological processes in the Cold Tongue region of the equatorial Pacific Ocean at 0N, 140W. This research objective was addressed using a one-dimensional multicomponent lower trophic level ecosystem model that includes detailed algal physiology, such as spectrally-dependent photosynthetic processes and iron limitation on algal growth. The ecosystem model is forced by a one-year (1992) time series of spectrally-dependent light, temperature, and water column mixing obtained from a Tropical Atmosphere-Ocean (TAO) Array mooring. Autotrophic growth is represented by five algal groups, which have …

Improved Associated Conditions In Rapid Intensifications Of Tropical Cyclones, Ruixin Yang, J. Tang, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Rapid intensification (RI) of tropical cyclones (TC) is a major error source in TC intensity forecasting. In order to improve the estimates of RI probability, association rules are used to facilitate the process of mining for candidate sets of conditions. Compared to the relation analysis method, the technique of association rules can simply explore associations among multiple conditions. Our mining results identified a reduced predictor set with fewer factors identified in previous studies but improved RI probabilities. That is, the RI probability with three conditions satisfied: low vertical shear, high humidity, and the TC being in an intensification phase is …