Atmospheric Sciences Commons^™

An Earlier Lidar Observation Of A Noctilucent Cloud Above Logan, Utah (41.7°N), Joshua P. Herron, Vincent B. Wickwar

Posters

The Atmospheric Lidar Observatory (ALO) Rayleigh-scatter lidar has been operated for 11 years on the Utah State University (USU) campus (41.7o N 111.8o W). During the morning of 22 June 1995 a noctilucent cloud (NLC) was observed with the lidar well away from the twilight periods when NLCs are visible. It lasted for approximately one hour. This observation and a second in 1999 [Wickwar et al., 2002] are very significant because they show the penetration of NLCs equatorward of 50°, which may have important implications for global change. Temperature profiles calculated at hourly intervals were at least 20 …

Extratropical Transition Of Southwest Pacific Tropical Cyclones. Part Ii: Midlatitude Circulation Characteristics, Mark R. Sinclair

Applied Aviation Sciences - Prescott

This second of two papers on extratropical transition (ET) over the southwest Pacific Ocean focuses on the variability of ET. A climatology of ET onset based on a previously described objective technique shows that ET commences 158 of latitude nearer the equator on average than similar cases from the Northern Hemisphere. Characteristic midlatitude circulation patterns accompanying ET near 308S are identified by means of empirical orthogonal function (EOF) analysis of 50 storms. The first eigenvector pattern, explaining nearly half the circulation variability, expresses relaxed and enhanced pressure gradients south of the storm that define composites similar to ‘‘cradled’’ and ‘‘captured’’ …

Evaluating Spatial Variability Of Precipitation In Kentucky With Exploratory Data Analysis, Daniel Taylor

Masters Theses & Specialist Projects

Spatial variability of precipitation is examined over the state of Kentucky and surrounding areas. The study focuses on the analysis of monthly precipitation totals from the period of 1961-2000. The purpose of the study is to develop a set of indices to represent the spatial variability of the study area for a given month. Various exploratory data analysis methods such as variography, kriging, and cluster analysis were used. The study attempts to quantify the second order (local) effects of the spatial variation of precipitation as a means to provide insight into the prediction of precipitation randomness. This task can be …

A Nonparametric Method For Separating Photosynthesis And Respiration Components In Co2 Flux Measurements, Chuixiang Yi, Runze Li, Peter S. Backwin, Ankur Desai, Daniel M. Ricciuto, Sean P. Burns, Andrew A. Turnipseed, Steven C. Wofsy, J. William Munger, Kell Wilson, Russell K. Monson

Publications and Research

Future climate change is expected to affect ecosystem-atmosphere CO₂ exchange, particularly through the influence of temperature. To date, however, few studies have shown that differences in the response of net ecosystem CO₂ exchange (NEE) to temperature among ecosystems can be explained by differences in the photosynthetic and respiratory processes that compose NEE. Using a new nonparametric statistical model, we analyzed data from four forest ecosystems. We observed that differences among forests in their ability to assimilate CO₂ as a function of temperature were attributable to consistent differences in the temperature dependence of photosynthesis and respiration. This observation …

Intercomparisons Of Airborne Measurements Of Aerosol Ionic Chemical Composition During Trace-P And Ace-Asia, Y Ma, R J. Weber, K Maxwell-Meier, D A. Orsini, Y-N Lee, B J. Huebert, S G. Howell, T H. Bertram, R. Talbot, Jack E. Dibb, Eric Scheuer

Earth Sciences

As part of the two field studies, Transport and Chemical Evolution over the Pacific (TRACE-P) and the Asian Aerosol Characterization Experiment (ACE-Asia), the inorganic chemical composition of tropospheric aerosols was measured over the western Pacific from three separate aircraft using various methods. Comparisons are made between the rapid online techniques of the particle into liquid sampler (PILS) for measurement of a suite of fine particle a mist chamber/ion chromatograph (MC/IC) measurement of fine sulfate, and the longer time-integrated filter and micro-orifice impactor (MOI) measurements. Comparisons between identical PILS on two separate aircraft flying in formation showed that they were highly …

A Comparison Of Similar Aerosol Measurements Made On The Nasa P3-B, Dc-8, And Nsf C-130 Aircraft During Trace-P And Ace-Asia, K G. Moore, A D. Clarke, V Kapustin, Cameron Mcnaughton, B E. Anderson, E L. Winstead, R J. Weber, Y Ma, Y N. Lee, R. Talbot, Jack E. Dibb, T Anderson, S Dougherty, D Covert, D Rogers

Earth Sciences

Two major aircraft experiments occurred off the Pacific coast of Asia during spring 2001: the NASA sponsored Transport and Chemical Evolution over the Pacific (TRACE-P) and the National Science Foundation (NSF) sponsored Aerosol Characterization Experiment-Asia (ACE-Asia). Both experiments studied emissions from the Asian continent (biomass burning, urban/industrial pollution, and dust). TRACE-P focused on trace gases and aerosol during March/April and was based primarily in Hong Kong and Yokota Air Force Base, Japan, and involved two aircraft: the NASA DC-8 and the NASA P3-B. ACE-Asia focused on aerosol and radiation during April/May and was based in Iwakuni Marine Corps Air Station, …

Carbonyl Sulfide And Carbon Disulfide: Large-Scale Distributions Over The Western Pacific And Emissions From Asia During Trace-P, Nicola J. Blake, David G. Streets, Jung -Hun Woo, Isobel J. Simpson, Jonathan Green, Simone Meinardi, Kazuyuki Kita, E L. Atlas, H Fuelberg, Glen Sachse, Melody A. Avery, S Vay, R. Talbot, Jack E. Dibb, A R. Bandy, D C. Thornton, F Sherwood Rowland, D R. Blake

Earth Sciences

An extensive set of carbonyl sulfide (OCS) and carbon disulfide (CS₂) observations were made as part of the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) project, which took place in the early spring 2001. TRACE-P sampling focused on the western Pacific region but in total included the geographic region 110°E to 290°E longitude, 5°N to 50°N latitude, and 0–12 km altitude. Substantial OCS and CS₂ enhancements were observed for a great many air masses of Chinese and Japanese origin during TRACE-P. Over the western Pacific, mean mixing ratios of long-lived OCS and shorter-lived CS_{2 …}

Atmospheric Lidar Observatory (Alo) Ten-Year Mesospheric Temperature Climatology, Joshua P. Herron, Vincent B. Wickwar

Posters

The Rayleigh-scatter lidar at the Atmospheric Lidar Observatory (ALO) on the Utah State University (USU) (41.7°N, 111.8°W) campus has been in operation since 1993. The temperature database now contains over ten years of Rayleigh-scatter temperatures. A multi-year temperature climatology has been calculated from these observations along with the RMS and interannual variability. These temperatures and the climatology are currently being used in a number of mesospheric studies, including mesospheric inversion layers, tides, planetary waves, cyclical variations, trends, longitudinal comparisons, and validation studies.

Examples Of Alo Results, Vincent B. Wickwar, Joshua P. Herron, Karen M. Nelson, Troy A. Wynn, Kristina Thomas, Eric M. Lundell

Presentations

No abstract provided.

A 700 Year Record Of Southern Hemisphere Extratropical Climate Variability, Paul A. Mayewski, Kirk A. Maasch, James W.C. White, Eric J. Steig, E A. Meyerson, Ian D. Goodwin, Vin Morgan, Tas D. Van Ommen, Mark Aj Curran, Joseph M. Souney Jr, K Kreutz

Earth Systems Research Center

Annually dated ice cores from West and East Antarctica provide proxies for past changes in atmospheric circulation over Antarctica and portions of the Southern Ocean, temperature in coastal West and East Antarctica, and the frequency of South Polar penetration of El Niño events. During the period AD 1700–1850, atmospheric circulation over the Antarctic and at least portions of the Southern Hemisphere underwent a mode switch departing from the out-of-phase alternation of multi-decadal long phases of EOF1 and EOF2 modes of the 850 hPa field over the Southern Hemisphere (as defined in the recent record by Thompson and Wallace, 2000; Thompson …

A Recommendation For An Enhanced Fujita Scale (Ef-Scale)

United States Department of Commerce: Staff Publications

Background

National Weather Service (NWS) personnel who are responsible for rating tornadoes have expressed frustrations in applying the Fujita Scale in a consistent and accurate manner. Weak links in a structural system or a slow-moving storm sometimes lead to an overrating of a tornado event. Several technical articles suggest that wind speeds associated with some descriptions of damage are too high. For example, a 260 mph wind speed is not required to completely destroy a well constructed house and blow away the debris. The damage occurs at significantly lower wind speeds. Minor et al. (1977) and Phan and Simiu (2003) …

Derivation Of A Self-Consistent Auroral Oval Model Using The Auroral Boundary Index, Keith A. Anderson

Theses and Dissertations

The position and intensity of the auroral oval has many implications for the Air Force from determining the effects of incoming electron flux on DoD systems to modeling the ionosphere to exploit current HF communications capabilities. The auroral morphology is a good indicator of the level at which space weather and its near-Earth consequences are occurring, and thus it is important to develop an auroral prediction model. However, since no purely physics-based models exist to describe the temporal and spatial evolution of the auroral zone, space weather practitioners and researchers are forced to produce statistical representations, “organized” by some relevant …

Comparative Study On The Use Of Coherent Radar-Derived Electric Fields Vs. Statistical Electric Fields For The Initialization Of A High-Latitude Ionospheric Model, Christopher M. Hogue

Theses and Dissertations

The structure and time development of the magnetosphere-ionosphere system have significant impacts on the Air Force and its mission. Specifically, an accurate knowledge of ionospheric plasma densities is important for the operation of many Air Force systems. This research analyzes plasma density structure development through comparing two distinct electric field models. The two models compared here are a commonly used statistical model created by Heppner and Maynard 1987, and a more recently developed model using real-time coherent radar measurements from the SuperDARN radar network. Ionospheric simulations were run using Utah State University s Time-Dependent Ionospheric Model (TDIM) with the two …

Estimating Equatorial F-Region Daytime Vertical E X B Drift Velocities From Ground-Based Magnetometer Measurements In The Philippine Longitude Sector, Shauna M. Kinkela

Theses and Dissertations

Ionospheric disturbances can severely impact Department of Defense (DoD) systems, such as radar. satellite. and navigation technologies. Forecasting disturbances and describing the Earth's ionosphere, in turn, relies upon innovative computer-based models that gather input parameters from ground and space-borne observations and empirical models for ionospheric drivers. Equatorial E x B drift velocities are significant input parameters that go into many ionospheric models, because they help describe vertical plasma motions near the magnetic equator. Previous work by Anderson, et al 2002 has demonstrated the ability to derive Peruvian longitude sector, daytime vertical E x B drifts from ground-based magnetometer data. The …

Constraints On The Sources Of Tropospheric Ozone From 210pb-7be-O3 Correlations, Hongyu Liu, Daniel Jacob, Jack E. Dibb, Arlene M. Fiore, Robert Yantosca

Earth Sciences

The 210Pb-7 Be-O3 relationships observed in three aircraft missions over the western Pacific (PEM-West A and B, TRACE-P) are simulated with a global three-dimensional chemical tracer model (GEOS-CHEM) driven by assimilated meteorological observations. Results are interpreted in terms of the constraints that they offer on sources of tropospheric ozone (O3). Aircraft observations of fresh Asian outflow show strong 210Pb-O3 correlations in September–October, but such correlations are only seen at low latitudes in February–March. Observations further downwind over the Pacific show stronger 210PbO3 correlations in February–March than in September–October. The model reproduces these results and attributes the seasonal contrast to strong …

Nighttime Removal Of Nox In The Summer Marine Boundary Layer, S S. Brown, Jack E. Dibb, H Stark, M Aldener, Marcy Vozzella, Sallie I. Whitlow, E J. Williams, Brian M. Lerner, R Jakoubek, A M. Middlebrook, J A. Degouw, C Warneke, P D. Goldan, W C. Kuster, W M. Angevine, D Sueper, Patricia K. Quinn, Timothy S. Bates, James Meagher, Fred C. Fehsenfeld, A R. Ravishankara

Earth Sciences

The nitrate radical, NO3, and dinitrogen pentoxide, N2O5, are two important components of nitrogen oxides that occur predominantly at night in the lower troposphere. Because a large fraction of NO2 reacts to form NO3 and N2O5 during the course of a night, their fate is an important determining factor to the overall fate of NOx (=NO and NO2). As a comprehensive test of nocturnal nitrogen oxide chemistry, concentrations of O3, NO, NO2, NO3, N2O5, HNO3 and a host of other relevant compounds, aerosol abundance and composition, and meteorological conditions were measured in the marine boundary layer from the NOAA research …

The Observed Covariance Between Ecosystem Carbon Exchange And Atmospheric Boundary Layer Dynamics At A Site In Northern Wisconsin, Chuixiang Yi, Kenneth J. Davis, Peter S. Bakwin, A. Scott Denning, Nina Zhang, Ankur Desai, John C. Lin, Christoph Gerbig

Publications and Research

Ecosystem CO₂ exchange and atmosphere boundary layer (ABL) mixing are correlated diurnally and seasonally as they are both driven by solar insulation. Tracer transport models predict that these covariance signals produce a meridional gradient of annual mean CO₂ concentration in the marine boundary layer that is half as strong as the signal produced by fossil fuel emissions. This rectifier effect is simulated by most global tracer transport models. However, observations to constrain the strength of these covariance signals in nature are lacking. We investigate the covariance between ecosystem carbon dioxide exchange and ABL dynamics by comparing one widely …

Developing A Forecast Tool For Cloud-To-Ground Lightning In The North Central And Northeastern United States, Manuel I. Folsom Jr.

Theses and Dissertations

Cloud-to-ground (CG) lightning is a hazard to the Air Force for both air and ground operations Forecasting CG lightning is a necessary and extremely important requirement for Air Force meteorologists and forecasters. The 15th Operational Weather Squadron requested a forecast tool capable of predicting CG lightning within a 25 and 10 nautical mile radius of the 13 military locations in their area of responsibility. To fulfill their request, forecast decision tools were created using a Classification and Regression Tree (CART) data analysis program. Four decision trees were produced for each location using the period of record from March through September, …

Verification Of The Mountain Wave Forecast Model's Stratospheric Turbulence Forecasts Using Sounding Data And Pilot Reports, Scott M. Miller

Theses and Dissertations

Since stratospheric turbulence (Stratoturb) is becoming an increased concern to the Air Force, the threat of damage to aircraft must be addressed. Therefore, the Air Force Weather Agency (AFWA) requests an accurate Stratoturb forecast model. In 2002, The Mountain Wave Forecast Model (MWFM) was modified in order to develop a Stratoturb forecast tool. Turbulence forecasts generated twice daily by the MWFM for locations over East Asia over a period of thirty days were compared to output from the Rawindsonde Observation (RAOB) program to determine if the model agreed with the program output. Although the results were promising, verification by aircraft …

Chemical Characterization Of Ambient Aerosol Collected During The Northeast Monsoon Season Over The Arabian Sea: Anions And Cations, Anne M. Johansen, Michael R. Hoffmann

All Faculty Scholarship for the College of the Sciences

Ambient aerosol samples were collected over the Arabian Sea during the month of March 1997, aboard the German R/V Sonne, as part of the German JGOFS project (Joint Global Ocean Flux Study). This is the third study in a series of analogous measurements taken over the Arabian Sea during different seasons of the monsoon. Dichotomous high volume collector samples were analyzed for anions and cations upon return to the laboratory. Anthropogenic pollutant concentrations were larger during the first part of the cruise, when air masses originated over the Indian subcontinent. Total NSS‐SO₄²⁻ concentrations amounted to 2.94 ± …

An Automated Method Of Predicting Clear-Air Turbulence, Brian L. Belson

Theses and Dissertations

Clear-air turbulence (CAT) prediction is vitally important to military aviation and the successful completion of Department of Defense (DoD) operations such as air to air refueling and new national defensive weapon systems such as directed energy platforms. The unique mission requirements of military aircraft often require strict avoidance of turbulent regions. Traditionally, weather forecasters have found it difficult to accurately predict CAT. In order to forecast regions where CAT might occur, forecasters must first determine the location of breaking waves caused by either Kelvin-Helmholtz instabilities or topographically forced internal gravity waves (mountain waves) in the atmosphere. The United States Air …

Atmospheric Simulation Using A Liquid Crystal Wavefront Controlling Device, Matthew R. Brooks

Theses and Dissertations

Test and evaluation of laser warning devices is important due to the increased use of laser devices in aerial applications. In this thesis, an atmospheric aberrating system is deve1oped to enable in-1ab testing of laser warning devices. This system employs laser 1ight at 632.8nm from a He1ium-Neon source and a spatial light modulator (SLM) to cause phase changes using a birefringent liquid crystaJ material. Before the system can be used, the SLM phase response must be quantified to ensure proper manipulation of index of refrnction. Additionally, diffraction from the SLM and rea1-world system scaling are addressed. Once completed, the atmospheric …

Relationships Between Surface And Column Aerosol Radiative Properties And Air Mass Transport At A Rural New England Site, J F. Slater, Jack E. Dibb

Earth Sciences

Chemical, physical, and radiative properties of surface and vertical column aerosols were measured at a rural site in southern New Hampshire from July 2000 to September 2001. The primary objective was to determine how intensive and extensive aerosol properties vary in air masses originating in different upwind regions. The data set also allows for an investigation of some of the relationships between surface and column aerosol properties at the site, and provides an estimate of direct radiative forcing by aerosols during the study period. Extensive properties (e.g., optical depth and chemical concentration) were at maximum values during times of south-southwest …

Asian Dust Storm Events Of Spring 2001 And Associated Pollutants Observed In New England By The Atmospheric Investigation, Regional Modeling, Analysis And Prediction (Airmap) Monitoring Network, Linsey J. Debell, Marcy Vozzella, R. Talbot, Jack E. Dibb

Earth Sciences

Between 18 April and 13 May 2001, three statistically extreme dust aerosol events were observed across the entire northeastern United States. High levels of bulk aerosol water-soluble Ca²⁺ (range = 42–482 pptv) and PM_2.5 elemental Ca (range = 19–156 pptv) were observed simultaneously at Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) and Interagency Monitoring of Protected Visual Environments (IMPROVE) stations. On the basis of Ca²⁺ concentrations, the average bulk dust concentration for all events across all four AIRMAP stations was estimated to be 7.4 μg/m³. There was no evidence of dust outbreaks in North …

El Niño Suppresses Antarctic Warming, Nancy A. N. Bertler, Peter J. Barrett, Paul Andrew Mayewski, Ryan L. Fogt, Karl J. Kreutz, James Shulmeister

Earth Science Faculty Scholarship

Here we present new isotope records derived from snow samples from the McMurdo Dry Valleys, Antarctica and re-analysis data of the European Centre for Medium-Range Weather Forecasts (ERA-40) to explain the connection between the warming of the Pacific sector of the Southern Ocean [Jacka and Budd, 1998; Jacobs et al., 2002] and the current cooling of the terrestrial Ross Sea region [Doran et al., 2002a]. Our analysis confirms previous findings that the warming is linked to the El Niño Southern Oscillation (ENSO) [Kwok and Comiso, 2002a, 2002b; Carleton, 2003; Ribera and Mann …

Variability In Accumulation Rates From Gpr Profiling On The West Antarctic Plateau, Vandy B. Spikes, Gordon S. Hamilton, Steven A. Arcone, Susan Kaspari, Paul Andrew Mayewski

Earth Science Faculty Scholarship

Isochronal layers in firn detected with ground-penetrating radar (GPR) and dated using results from ice-core analyses are used to calculate accumulation rates along a 100 km across-flow profile in West Antarctica. Accumulation rates are shown to be highly variable over short distances. Elevation measurements from global positioning system surveys show that accumulation rates derived from shallow horizons correlate well with surface undulations, which implies that wind redistribution of snow is the leading cause of this variability. Temporal changes in accumulation rate over 25-185 year intervals are smoothed to along-track length scales comparable to surface undulations in order to identify trends …

Satellite Evidence Of Hurricane-Induced Phytoplankton Blooms In An Oceanic Desert, S. M. Babin, J. A. Carton, T. D. Dickey, J. D. Wiggert

CCPO Publications

The physical effects of hurricanes include deepening of the mixed layer and decreasing of the sea surface temperature in response to entrainment, curl-induced upwelling, and increased upper ocean cooling. However, the biological effects of hurricanes remain relatively unexplored. In this paper, we examine the passages of 13 hurricanes through the Sargasso Sea region of the North Atlantic during the years 1998 through 2001. Remotely sensed ocean color shows increased concentrations of surface chlorophyll within the cool wakes of the hurricanes, apparently in response to the injection of nutrients and/or biogenic pigments into the oligotrophic surface waters. This increase in post-storm …

Correction To "Breaking Of Thunderstorm-Generated Gravity Waves As A Source Of Short-Period Ducted Waves At Mesopause Altitudes", Jonathan B. Snively, Victor P. Pasko

Publications

No abstract provided.

An Analysis Of Simulated Long-Term Soil Moisture Data For Three Land Uses Under Contrasting Hydroclimatic Conditions In The Northern Great Plains, Rezaul Mamood, Kenneth G. Hubbard

HPRCC Personnel Publications

Soil moisture (SM) plays an important role in land surface and atmosphere interactions. It modifies energy balance near the surface and the rate of water cycling between land and atmosphere. The lack of observed SM data prohibits understanding of SM variations at climate scales under varying land uses. However, with simulation models it is possible to develop a long-term SM dataset and study these issues. In this paper a water balance model is used to provide a quantitative assessment of SM climatologies for three land uses, namely, irrigated corn, rain-fed corn, and grass, grown under three hydroclimatic regimes in Nebraska. …

Sources And Cycling Of Carbonyl Sulfide In The Sargasso Sea, Gregory A. Cutter, Lynda S. Cutter, Katherine C. Filippino

OES Faculty Publications

The cycling of the radiatively important gas carbonyl sulfide (OCS) was studied in surface waters of the Sargasso Sea. In August 1999, surface OCS concentrations averaged 8.6 pmol L^-1, showed minor diel variations, and varied little with depth. An OCS precursor, total dissolved organic sulfur (DOS), was lowest at the surface (40 nmol L^-1) and increased with depth. The photoproduction rate of OCS from in situ incubations averaged 9.6 pmol L^-1 h^-1, whereas dark production was 7.0 pmol L^-1 h^-1. Apparent quantum yields were 10^-5-10^-7 from 313-436 …