Dugway Proving Ground Research Articles

Detection of bioaerosols using hyperspectral LIF-LIDAR during S/K challenge II campaign at Dugway

This study showcases the importance of the remote sensing of biological aerosols for both homeland security and environmental protection. We demonstrate the application of a hyperspectral Laser Induced Fluorescence Light Detection and Ranging (LIF-LIDAR) system for the remote sensing of bioaerosols during the international S/K CHALLENGE II field campaign at the U.S. Army Dugway Proving Ground (DPG). The system employs UV photoexcitation at 266 nm and fluorescence spectral analysis in the range of 250–650 nm at a resolution of approximately 2 nm. A two-stage Microchannel Plate (MCP)-ICCD-based receiver capable of single photon-counting detection limit was used. During the campaign, four different bioaerosol simulants were studied in enclosed chambers and open space experiments at night and at distances of 0.5–2 km. A real-time Spectral Angle Mapping (SAM) algorithm was implemented to identify unknown bioaerosol clouds, dust, and combustion plumes as they spread in the open atmosphere. Additionally, we conducted preliminary tests in our institute, which demonstrated the system's ability to identify Ovalbumin (OV) aerosol despite being covered by a thick dust cloud. During the field measurements in DPG, we continuously tracked the fluorescence signature of OV aerosol as it spread in the atmosphere from a distance of 1.5 km for over 20 min. The overall detection performance during the S/K CHALLENGE II was 49 out of 52 trials, indicating a success rate of about 94%. The discussion centers on spectral identification statistics of the unknown dispersed bioaerosol as well as the implications of false-positive and false-negative events.

Simulations of Mesoscale Flow Systems around Dugway Proving Ground Using the WRF Modeling System

It is widely recognized that regions with complex heterogeneous topography and land-use properties produce a variety of diurnal mesoscale and microscale flows, which can be modified or even masked by significant large-scale synoptic forcing. These flows can be produced through both dynamic and thermal-forcing processes. Recent field programs such as the Terrain-induced Rotor Experiment (T-REX), Mountain Terrain Atmospheric Modeling and Observations Program (MATERHORN), and Perdigao have been used to observe and model flow behaviors under different topographical and large-scale meteorological conditions. Using the Advanced research version of the Weather Research and Forecast (WRF-ARW) model, we applied multi-nesting using an interactive one-way nesting approach to resolve to a sub-kilometer inner-grid spacing (0.452 km). Our interest was in the intensive observation period 6 (IOP6) of the Fall 2012 MATERHORN campaign conducted over Dugway Proving Ground (DPG) in Utah. An initial review of the IOP6 suggested that a range of diurnal flows were present, and that a relatively small subset of model setup configurations would be able to capture the general flows of this period. The review also led us to believe that this same subset would be able to capture differences due to variations in choice of model boundary-layer physics, land surface physics, land use/soil type specifications, and larger-scale meteorological conditions. A high model vertical resolution was used, with 90 vertical sigma levels applied. The IOP6 spanned the period of 2012 0800 UTC 14 October–0800 UTC 15 October. Based upon a lack of deep convection and moist microphysics throughout IOP6, we included comparison of planetary boundary layer (PBL) turbulence parameterization schemes even at the sub-kilometer grid spacing. We focused upon the gross model performance over our inner nest; therefore, a detailed comparison of the effects of model horizontal resolution are excluded. For surface parameters of wind and temperature, we compare mean absolute error and bias scores throughout the period at a number of surface meteorological observing sites. We found that despite attention given to the boundary layer turbulence physics, radiation physics and model vertical resolution, the results seemed to indicate more impact from the choices of thermal soil conductivity parameterization, land surface/soil texture category classification (and associated static property-parameter values), and large-scale forcing model. This finding lends support to what other researchers have found related to how these same forcings can exert a strong influence upon mesoscale flows around DPG. Our findings suggest that the two nights of IOP6 offer a pair of excellent consecutive nights to explore many of the forcing features important to local complex terrain flow. The flows of interest in this case included valley, anabatic/katabatic, and playa breeze systems. Subjective evidence was also found to support an influence provided by the modest synoptic northwesterly flow present within the lower troposphere (mainly on the night of 14 October). Follow-on research using the WRF-ARW capability to nest directly from mesoscale-to-LES can leverage IOP6 further. For example, to uncover more detailed and focused aspects of the dynamic and thermodynamic forcings contributing to the DPG diurnal flows.

Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering (IDEAL): high-resolution in situ observations and modeling in and above the nocturnal boundary layer

Abstract. The Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering (IDEAL) program was conceived to improve understanding of the dynamics of thin strongly stratified “sheet” and deeper weakly stratified “layer” (S&L) structures in the lower troposphere under strongly stable conditions. The field portion of the IDEAL program was conducted from 24 October to 15 November 2017 at Dugway Proving Ground, Utah, to target nighttime lower troposphere S&L conditions. It employed a synergistic combination of observations by multiple simultaneous DataHawk-2 (DH2) small unmanned aircraft systems (sUASs) and concurrent ground-based profiling by the NCAR Earth Observing Laboratory Integrated Sounding System (ISS) comprising a wind profiler radar and hourly high-resolution radiosonde soundings. DH2 measurement intervals as well as vertical (∼ 2–4 km) and horizontal (∼ 5–10 km) flight trajectories were chosen based on local high-resolution weather forecasting and guided by near-real-time ISS measurements. These flights combined simultaneous vertical and slant-path profiling, and/or horizontal racetrack sampling, spanning several hours before sunrise. High-spatial- and temporal-resolution data were downlinked in real time to enable near-real-time changes in DH2 flight paths based on observed flow features. The IDEAL field program performed 70 DH2 flights on 16 d, coordinated with 93 high-resolution radiosonde soundings. In this paper, raw and derived measurements from this campaign are outlined, and preliminary analyses are briefly described. This data set, along with “quick look” figures, is available for access by other researchers, as described herein.

Distinguishing Time Scales of Katabatic Flow in Complex Terrain

To examine spatial and temporal scales of katabatic flow, a distributed temperature sensing (DTS) optical fiber was deployed 2 km down a mild slope irregularly interrupted by small-scale drainage features as part of the Mountain Terrain Atmospheric Modeling and Observation (MATERHORN) experiment conducted at the U.S. Army Dugway Proving Ground, Utah. The fiber was suspended at two heights near the surface, enabling measurement of variations in lapse rate near the surface at meter-scale spatial resolution with 1-min temporal resolution. Experimental results derived from the DTS and tower-mounted instrumentation indicate that airflow through small-scale drainage features regulated the local cooling rate whereas topographic slope and distance along the drainage strongly influenced the larger-scale cooling rate. Empirical results indicate that local cooling rate decays exponentially after local sunset and basin-wide cooling rate decreases linearly with time. The difference in the functional form for cooling rate between local and basin-wide scales suggests that small-scale features have faster timescales that manifests most strongly shortly after local sunset. More generally, partitioning drainage flow by scale provides insight and a methodology for improved understanding of drainage flow in complex terrain.

Overview of the Jack Rabbit II (JR II) field experiments and summary of the methods used in the dispersion model comparisons

This paper serves as an introduction to the special Atmospheric Environment issue on comparisons of 17 widely-used dense-gas dispersion models using observations from the Jack Rabbit II (JR II) chlorine release experiments, which were led by the U.S. Department of Homeland Security Science & Technology (DHS S&T) Chemical Security Analysis Center (CSAC) and a collaborative team of interagency partners, and conducted at the U.S. Army Dugway Proving Ground in 2015 and 2016. Nine of the 17 models that were compared were from outside the U.S. Other papers in the Special Issue describe specific aspects (e.g., observations of emissions, meteorology, and concentrations) of the JR II field experiments, results of individual dispersion model simulations for the models and comparisons of model predictions with JR II observations and other models. This paper provides a general overview of the field experiments and a brief summary of the model comparison goals and methods.

Portable membrane inlet mass spectrometric detection and analysis of chemical warfare agent simulants at the U.S. Army Dugway Proving Ground S/K challenge event

There has been a significant demand for the development and improvement of technology used for the detection and identification of Chemical Warfare Agents (CWAs). Some of the current detection technology being used by the U.S. government includes multipass gas cell coupled Fourier Transform Infrared (FTIR) spectroscopy and Lightweight Chemical Detectors (LCD) systems. While these systems possess adequate sensitivity to detect CWAs in general, their analysis times are not considered 'rapid' nor are they able to identify the specific CWA. The U.S. Army Dugway Proving Ground's annual S/K Challenge event provides the opportunity to assess the performance and reliability of prospective detection instrumentation being developed by researchers worldwide to optimize their performance. To do so, trial testing of CWA simulants in both indoor and outdoor environments was performed, mimicking past attack scenarios. Membrane Inlet Mass Spectrometric (MIMS) technology on a portable system was successful in performing a rapid analysis along with identification of each CWA simulant utilized during the trials. The MIMS system can detect and quantify low-mass permeable compounds with parts-per-trillion limits of detection. This allows for analysis to be achieved within seconds after the initial exposure time, which is significantly faster than the FTIR and LCD systems currently used.

The Impact of Surface Temperature Heterogeneity on Near-Surface Heat Transport

Experimental closure of the surface energy balance during convective periods is a long-standing problem. With experimental data from the Idealized horizontal Planar Array experiment for Quantifying Surface heterogeneity, the terms of the temperature-tendency equation are computed, with an emphasis on the total derivative. The experiment occurred at the Surface Layer Turbulence and Environmental Science Test facility at the U.S. Army Dugway Proving Ground during the summer of 2019. The experimental layout contained an array of 21 flux stations over a 1 km $$^2$$ grid. Sensible heat fluxes show high spatial variability, with maximum variability occurring during convective periods. Maximum variability in the vertical heat flux is 50–80 W m $$^{-2}$$ (median variability of 40%), while in the horizontal flux, it is 200–500 W m $$^{-2}$$ (median variability of 48% for the streamwise and 40% for the spanwise fluxes). Ensemble averages computed during convective afternoon periods show large magnitudes of horizontal advection (48 W m $$^{-3}$$ or 172 K h $$^{-1}$$ ) and vertical flux divergence (13 W m $$^{-3}$$ or 47 K h $$^{-1}$$ ). Probability density functions of the total derivative from convective cases show mean volumetric heating rates of 43 W m $$^{-3}$$ (154 K h $$^{-1}$$ ) compared to 13 W m $$^{-3}$$ (47 K h $$^{-1}$$ ) on non-convective days. A conceptual model based on persistent mean flow structures from local-surface-temperature heterogeneities may explain the observed advection. The model describes the difference between locally-driven advection and advection driven by larger-scale forcings. Of the cases examined, 83% with streamwise and 81% with spanwise advection during unstable periods are classified as locally driven by nearby surface thermal heterogeneities.

Concentration Fluctuations of Single Particle Stochastic Lagrangian Model Assessment with Experimental Field Data

A single particle Lagrangian Stochastic model has been developed and applied with the purpose of simulating the concentration fluctuations dispersion. This model treats concentration variance as a quantity whose motion is driven by an advection-diffusion process so that it can be studied by a single particle model. A parameterization for both velocity standard deviations and Lagrangian time-scales is required as input to the model. The paper is focused on the estimation of the best parameterization needed to simulate both mean and standard deviation concentrations in a case study. We consider the FFT-07 field experiment. The trials took place at Dugway Proving Ground, UTAH (USA) and consist of a dispersion analysis of a gas emitted from a point-like source in different atmospheric conditions with a continuous emission technique. The very small spatial scales (a few hundred meters) and short duration (about 10 minutes) that characterize the trials make the comparison with model results very challenging, since traditional boundary layer parameterizations fail in correctly reproducing the turbulent field and, as a consequence, the dispersion simulation yields unsatisfactorily results. We vary the coefficients of the turbulence parameterization to match the small-scale turbulence. Furthermore, we show that the parameterization for the variance dissipation time-scale, already tested in neutral conditions, can be used also in stable and unstable conditions and in low-wind speed conditions. The model gives good results as far as mean concentration is concerned and rather satisfactory results for the concentration standard deviations. Comparison between model results and observation is shown through both statistical and graphical analyses.

JRII special sonic anemometer study: A first comparison of building wakes measurements with different levels of numerical modelling approaches

After the summer 2015 chlorine releases during the Jack Rabbit II field experiment at Dugway Proving Ground, a special sonic anemometer study was carried out in October 2015 and March 2016. The goal was to provide documented wind fields in similar conditions to the actual releases and to study building wakes without risk for the instruments. This study included 30 sonic anemometers that were placed around these “buildings” to best capture the recirculating regions. Building wakes are important for the dispersion of pollutants in cities and around industrial plants and therefore we have selected two time periods during March 2016, in order to present model to model and model to data comparisons. There are four models involved in the comparison ranging from a diagnostic wind model with wake parameterization and Lagrangian particle dispersion and a CFD model with a k-ε turbulence closure and solving the Eulerian dispersion equation. Detailed comparisons are carried out for the wind speed and for the turbulence level. Six virtual releases are added in the simulations to investigate how the wake resolving method can affect the dispersion. For the wind speed comparison, the models give fair to good comparison with the sonic measurements. However, for the turbulence comparison the results clearly show a need for improvement, even for the k-ε closure, which still provides the best results. For the concentrations, for which there is no corresponding measurements, we find that the simulations are much closer than for the turbulence comparison.

Simulation of a dense gas chlorine release with a Lagrangian particle dispersion model (LPDM)

In 2015, 2016, nine chlorine releases experiments took place at Dugway Proving Ground (Utah, USA). Five trials conducted in 2015 featured a grid of CONEX shipping containers around the release tank to simulate an idealized urban area. The trials were a great occasion to collect data describing the dynamics of “high molecular weight” species in an idealized urban environment.This paper proposes a comparison of the PMSS (Parallel Micro-Swift Micro-Spray) suite against the experimental data from four of the trials, following the choice made by an international model inter-comparison team. PMSS combines two MPI parallelized urban modelling subsystems: (1) PSWIFT phenomenologically accounts for 3D wind flow and turbulence around buildings, and (2) PSPRAY simulates air-based contaminant dispersion in urban areas using a stochastic Lagrangian Particle Dispersion Model.For this comparison, PMSS is deployed first on a hypothetic configuration and compared to the Code_Saturne CFD model, and then using the data of the trials 1, 5, 6 and 7 performed during JRII (Jack Rabbit II) 2015 and 2016. The initial momentum due to the tank discharge and the dense gas and droplet effects of the pressurized chlorine release are modelled using a dedicated radial source term jet and the Glendening equations. In trials 1 and 5, the influence of the CONEX shipping containers on the wind flow and the dispersion is explicitly considered. While spread through a large interval, the chlorine concentrations are computed both in the near field and in the far field (up to 11 km) using PMSS nesting capabilities. The results of the model are compared with the experimental data and sensitivity tests are also presented.

DRIFT dispersion model predictions for the Jack Rabbit II model inter-comparison exercise

In 2015 and 2016, the US Army conducted nine large-scale chlorine releases at the Dugway Proving Ground in Utah, known as the Jack Rabbit II trials. The purpose of these experiments was to improve our understanding of pressure-liquefied chlorine releases and atmospheric dispersion, and to provide useful practical knowledge for emergency responders. Data from three of the Jack Rabbit II trials (Trials 1, 6 and 7) were subsequently selected for an international model inter-comparison exercise, which included modelling contributions from the US, UK, Canada, France, Germany, Sweden, Finland and the European Commission. This paper provides details of one of the UK contributions to that exercise, using the DRIFT integral dispersion model. Participants in the exercise were given a set of prescribed model input conditions. The methodology used in DRIFT to model these conditions is described here, which consisted of three runs: a baseline case and two sensitivity tests that examined the effect of variations in the modelled wind-speed profile and the dry deposition rate. A brief review is also provided of the experimental data used for the model inter-comparison exercise. Gas concentrations were measured in the Jack Rabbit II trials using an extensive array of gas sensors arranged on arcs downwind from the release point. Four types of sensors were used, which each had calibration and/or saturation limits. In some of the trials, sensors that recorded the highest concentrations on an arc were saturated with gas and under-recorded the actual concentrations. In other cases, especially near the source, there were only a few sensors on an arc and therefore it is uncertain whether the plume maximum concentrations were recorded. Results from DRIFT are compared to the Jack Rabbit II data in two ways. Firstly, against the full dataset of maximum arc-wise concentrations, and secondly against the subset of measurements that were unaffected by saturation issues or there being a sparse sensor array. In the first case, DRIFT gives higher concentrations than were measured on average, noting that some measurements probably under-recorded the concentration owing to the previously mentioned sensor saturation issues. In the second case, using the more reliable dataset, the statistical performance of DRIFT falls within commonly-used dense-gas model acceptance criteria. Sensitivity tests on the wind speed profile and dry deposition rate had an effect on the DRIFT predictions in Trial 1, but little impact in Trials 6 and 7. This behaviour is likely to be due to the changing meteorology during Trial 1, and the lower wind speed and smaller chlorine mass released in that trial. Remaining knowledge gaps and possible future directions for research are discussed. These include further work on dry deposition, modelling of the other Jack Rabbit II trials (potentially using source models as well as prescribed common source conditions), and comparisons of predicted and measured toxic load, calculated from the time-varying concentrations.

Meteorological data recommendations for input to dispersion models applied to Jack Rabbit II trials

Abstract The Jack Rabbit II (JR II) chlorine field experiment observations are being used in a multi-dispersion model comparison exercise. So that all models are using consistent meteorological inputs, we analyzed the many early-morning meteorological observations that were taken at Dugway Proving Ground (DPG), Utah, during the nine chlorine release trials during JR II to produce recommendations for surface and vertical profile meteorological variables. The JR II field experiment included a mesonetwork of about 35 surface wind sites, a surface energy balance site, three 32 m towers located 1 km apart, and several vertical sounding instruments. The challenge is to determine a single set of meteorological inputs for the dispersion models. It is assumed that the recommended meteorological conditions represent the flat desert about 100 m upwind of the chlorine release location. Recommendations of surface winds, and momentum and sensible heat fluxes for each early-morning field trial are based on averages of sonic anemometer observations at 2 m on the upwind 32 m tower and at 2.5 m on a nearby “Energy Balance” station, for the half hour period during which the chlorine release took place. These observations were also used to estimate the surface roughness length, zo = 0.5 mm, for the flat desert. Single vertical profiles of wind speed, wind direction, and temperature are specified for each trial for a time close to the chlorine release time, based on medians of observations at five levels on the three 32 m towers, a radiosonde, a minisodar, and two wind profilers (449 MHz and 921 MHz). During the early morning releases, as the sun rose and heated the surface, the boundary layer was transient. The surface boundary layer was stable for releases from about 7:30 to about 8:30 (local time) and was marked by a shallow mixed layer (about 8–16 m) for releases during the next hour. Above the 32 m tower tops, the atmosphere was stable during all release trials up to elevations of a few hundred meters. Large wind direction shears were usually found in this layer, since the near-surface flow was a drainage (katabatic) down-valley flow (from about 165°), while the synoptic flow above 100 m was from the west.

Characterizing Variations in Concentration Data Measured From Unknown Releases

The statistics of concentration data, measured during unknown atmospheric dispersion events, are not fully understood although they are required in modeling, assessment, uncertainty analysis, and information fusion. The concentrations measured over a field of monitoring network is regarded as a vector which contains both magnitude and direction. Traditional statistics (mean, standard deviations, etc.) based on magnitude of concentration data summarize data properties but are limited in characterizing variations in data and their modeling quality. Comparatively, directions are efficient in providing valuable information to address these issues. Here we propose a statistical framework which transforms concentration measurements into directions projected on a hypersphere and analyzes their orientation and distribution. The directional data measured in identical conditions are expected to be rotationally symmetric around its principal axis and follow Watson distribution. The clustering parameter of Watson distribution measures tightness of directional data and, thus, can measure indirectly variations in observed data. It is shown that the clustering parameter is able to summarize an overall variation in data and modeling quality of data in a dispersion trial. The study analyzes real data taken from continuous release experiments, called “Fusion Field Trials,” conducted at Dugway Proving Ground, Utah, United States.

Analysis of a series of urban-scale chlorine dispersion experiments and implications on indoor health consequences

In the United States, industrial compounds are routinely transported by rail in pressurized vessels, often near urban areas. A rupture of a vessel, for example due to a derailment, can result in the rapid release of a liquid-aerosol-gas mixture. The health consequences of such a release, especially close to population centers, are not well understood. To address this question, a series of controlled experimental releases of pressurized chlorine (Cl2) was conducted at the Dugway Proving Ground (Dugway, Utah). Each trial consisted of the sudden breach of a tank containing at least 4,500 kg (kg) of pressurized liquid Cl2. In this paper, we report on measured Cl2 concentrations in three test structures downwind of the release. Based on these data, we estimate the indoor-outdoor exchange, transport through a multi-room structure, and the first-order loss rate due to reaction or sorption. This loss rate is particularly important for consequence assessment. For example, in a mobile office with a ventilation rate of about three air changes per hour, the reaction loss rate was approximately 2.5 h−1. This accounts for a nearly 20 percent reduction in toxic load to indoor occupants. Finally, the paper discusses the modeling and analysis of a typical urban hazard assessment.

Timeline for Ronald Lorenz Ives

Timeline for Ronald Lorenz Ives Bill Broyles (bio) 1909. Born October 12 in Cleveland, Ohio. 1911. His family moved to Philadelphia, Pennsylvania. 1918. His family moved to Upper Montclair, New Jersey. 1921 or 1922. He ran away from home to Colorado. 1922. Ronald enrolled in Montclair High School for fall semester. 1926. Part-time job doing radio work at Adams-Morgan in Montclair, New Jersey. 1927. Part-time job doing non-sync sound work at Flextone Talking Co., Montclair, New Jersey. [End Page 397] 1928. Graduated from Montclair High School in June, taking 6 years and standing in the bottom quarter of his class. 1928. Made first visit to Mexico and the Pinacate region, during summer. 1929–1931. Enrolled at Stevens Institute of Technology as a part-time student. 1928–1929. Instrument manufacturing at Weston Electric Company, Newark, New Jersey. 1930. Obtained his radio-telephone license. 1930–1938. Self-employed as freelance writer and photographer in Hoboken, New Jersey, and Boulder, Colorado. 1931. Made an extended trip to the Southwest, including Grand Canyon, Zion, and Sierra Pinacate. 1932. Published his first article. At least 600 technical articles and 230 non-technical articles followed. 1932–1937. Student at University of Colorado, Boulder. Enrolled June 20, 1932. Transferred some credits from Stevens Institute of Technology. BA degree, June 10, 1935. Provisionally entered graduate school January 2, 1935. MS in geology, June 14, 1937, "Glaciology of the Monarch Valley, Grand County, Colorado." 1937, June–January 1938. While living in Colorado, Ronald worked for Science Services Company, Washington, D.C., as an editorial staff writer, and did occasional freelance writing even after 1938. 1937–April 1940. Field surveys. Self-employed independent researcher, Boulder, Colorado. Also, part-time radio operator for the Municipal Police Department, Boulder, Colorado. 1940, April–November 1941. Radio operator with American Airlines, Fort Worth, Texas. 1941, November–April 1942. Electrical research with Douglas Aircraft Company, Santa Monica, California. 1942, April–July 1943. U.S. Army Signal Corps General Development Labs, Army Chemical Corps in Red Bank, New Jersey, and Dugway Proving Ground in Tooele, Utah. Another report says he was employed as a meteorologist at the Fort Monmouth Signal Corps Engineering Laboratories from May 13, 1942, to November 15, 1942, by the Civilian Personnel Branch, U.S. Army Signal Corps, when he transferred to Dugway Proving Grounds. [End Page 398] 1943, July 17–July 14, 1946. A soldier in U.S. Army, mostly at Dugway Proving Grounds. 1946, July–August 1950. Student, research associate, and instructor in Department of Geography, Indiana University, Bloomington, Indiana. Entered graduate school in geography on October 11, 1946. MA degree in geography, October 15, 1947, "Climate of the Southern Salt Lake Desert, Utah." PhD degree in geomorphology, June 12, 1950, "Chinook Winds in the Colorado High Plains Region." 1950, August 24–April 1, 1951. Instructor at Armament School, Lowry Air Force Base, Denver, Colorado (GS-7). Honorably discharged U.S. Army Reserve April 1, 1953. 1951–1955. Cornell Aeronautical Laboratory, Buffalo. A principal physicist and later a principal engineer. His work consisted of evaluating various military ideas for practicality and conducting research on some of them. He also designed and built equipment, and inspected and evaluated military equipment and operational methods, suggesting improvements or modifications where possible. 1953. His father, Herbert E. Ives, died. 1955–1968. Research in Palo Alto. 1955–1958. Tronicon, Inc., a research and development subcontractor for military devices and instrumentation. The company later was known as John C. Beckman Co. and then Beckman and Whitley, Inc. 1958–1962. Stanford Aerosol Laboratory at Palo Alto, a university research lab, where he worked as an electronic engineer on a series of special meteorological instruments being developed for the Army Chemical Corps. 1962–1968. Metronics, Inc., Palo Alto, California. Same sort of work. 1968–1975. Employed as assistant professor of geography at Northern Arizona University in Flagstaff. Taught a variety of geography classes. 1972. Suffered serious injuries in Jeep wreck. 1974. His mother, Mabel Lorenz Ives, died. [End Page 399] 1975. Retired from Northern Arizona University, mandatorily. 1982. Died February 26 in Tucson, Arizona. 1984. Book published: José Velásquez: Saga of a Borderland Soldier. Tucson: Southwestern Mission Research Center. Finished with assistance from Father...

3. Soldier with a Notebook

3. Soldier with a Notebook Bill Broyles (bio) In April 1942 Ives left Douglas Aircraft and as a civilian went to work for the U.S. Army Signal Corps and the Army Chemical Corps, in succession, at the Presidio of San Francisco, then Fort Monmouth, New [End Page 280] Jersey, and then Dugway Proving Ground, Utah. He seems to have found a niche working with weather instruments, probably based on his limited experience monitoring weather in the Rockies. At the Presidio and Fort Monmouth he took a series of military training courses, though he makes no mention of anything like a boot camp. And he was assigned to Dugway as chief of the Meteorology Section. There, in his words, he "made standard and special weather observations, trained personnel in special chemical techniques, designed, built, tested, and operated a wide variety of special instruments for chemical meteorological work, including telemetering instruments for use in hazardous locations. Prepared reports on same, with recommendations for mass production, and instruction manuals for their use. Made, operated, and evaluated radiological instruments for tracer researches in connection with same."151 It is unclear whether Ives volunteered for the army or was drafted for World War II, but on July 17, 1943, he was inducted. His draft board was in Boulder, Colorado, but he gave his address as Upper Montclair, New Jersey, when he entered on duty as a second lieutenant "commissioned directly from civil life," undoubtedly because he was college educated with a master's degree. His discharge papers show work experience as a meteorologist with the U.S. Army Signal Corps; Chemical Warfare Service, U.S. Army; and the American Philosophical Society, Boulder, Colorado, 1938–1943, which at first appears perplexing but the society was the funding connection to his geological study for the Big Thompson project. Along the way he earned low-level security clearances, while his father, as head of Bell Laboratories, undoubtedly had high-level security clearances, because the lab had a role in perfecting top-secret projects like radar and infrared sniperscopes. His army physical qualified him for Limited Service based on some existing physical conditions. His health was "normal," with vitals as height, 69½ inches; 131 pounds; pulse of 88; and blood pressure of 125/80. His vision was 20/80 in his right eye and 20/70 in the left, both correctable to 20/20. Of interest, the report notes an appendectomy in 1931, fractured ribs on both sides in 1932, and both feet being "frozen severely" in 1928 with his right small toe being amputated, though he continued to work at altitudes and in cold doing search and rescue and geological research without further ill effects. The medical board notes his being 6 pounds underweight for his height and age and having deficient circulation in his feet, but gave him a waiver and recommended him for limited duty.152 [End Page 281] Ives's version of what happened reads like comedy, one that many veterans can relate to, but it was nothing to sneer at. He declared, I worked for Douglas Aircraft on the development of the C-54. That became the DC-4. One day I was told, "Hey, you're working for the Signal Corps." And I said, "Hell I am. I'm working for Douglas." "You're under orders." So suddenly I found myself in Ft. Monmouth, New Jersey. I was there about four weeks and I heard "Hey, you're to go out and start a meteorological station at Dugway, Utah." I said, "Where in the hell is this Dugway." And he showed me on the map. And so I went to Dugway and with some Signal Corps helpers set up a meteorological station there on the Chemical Corps proving ground. One day more papers came through and instead of being an employee of the Signal Corps, I was suddenly an employee of the Army Chemical Corps. And then a few months later, the commander called me in and said, "You're no longer a civilian." I said, "Now what happened?" "A presidential order. You're a first lieutenant." I said, "What difference does that make?" He said, "$200 a month less in pay...

Group effects of a non‐native plant invasion on rodent abundance

AbstractCheatgrass (Bromus tectorum) is the most prolific invading plant in western North America. Investigations determining the impact of this invasion on population state variables and community dynamics of rodents have largely occurred at the community or species level, creating a knowledge gap as to whether rodents affiliated by a shared taxonomy or other grouping are differentially affected by cheatgrass invasion. We examined rodent abundance along a gradient of cheatgrass cover using various groupings of two nocturnal rodent taxa comprising the majority of the rodent community in the Great Basin Desert. In the summers of 2010–2013, rodents were sampled and vegetation was measured on the U.S. Army Dugway Proving Ground in the Great Basin Desert of Utah, USA. We separately examined estimates of rodent abundance for all combined species within the Cricetidae and Heteromyidae families, the most numerically dominant species, and uncommon species pooled in relation to cheatgrass invasion severity. We detected an expected negative linear relationship between invasion severity and abundance for all cricetid groupings, including the most numerically dominant species, the deer mouse (Peromyscus maniculatus). Unexpectedly, heteromyid abundance exhibited an initial positive relationship, reached a threshold, and then exhibited a negative relationship, a phenomenon driven by Ord's kangaroo rats (Dipodomys ordii), the most numerically dominant species. We speculate this non‐linear finding was caused by a combination of trophic and non‐trophic pathways. Our findings provide new insight as to the potential for differential effects of cheatgrass on rodents in arid portions of the western United States. We suggest that future investigations on cheatgrass, and plant invader effects in general, consider parsing animal communities of interest by various taxonomic and/or ecological groupings rather than focusing exclusively on individual species or entire communities.

Simulation of stably stratified flow in complex terrain: flow structures and dividing streamline

The advanced research version of the weather research and forecasting model was employed to simulate Intense Operational Periods of the field campaigns of the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program with a 0.5 km horizontal resolution. The focus was on synoptically dominated stably stratified periods, with the mean flow approaching a strongly non-symmetrical rugged topography—the Granite Mountain of the US Army Dugway Proving Ground, Utah. The model was validated against a comprehensive set of MATERHORN data. The special in-house developed software enabled calculations of energetics and pressure anomalies along individual streamlines and tracing of spatial trajectories of streamlines. Owing to complexities of natural flows, for example, the directional shear (skewed vertical velocity profiles) and irregular topographic shape, the flow patterns depend on multiple parameters, although in idealized cases the flow is described by a single parameter (Froude number or a variant). Streamlines at different altitudes of a given location diverged rapidly, making it difficult to study the dividing streamline concept. The new software allowed identification of the dividing streamline passing over the highest crest (summit) of the mountains and its trajectory. The upstream height of the dividing streamline did not follow the well-known Sheppard’s formula. Three cases of flow patterns are presented, identified based on the presence of lee waves, flow separation, horizontal vortex shedding and hydraulics jumps.

Dense gas dispersion model development and testing for the Jack Rabbit II phase 1 chlorine release experiments

In 2015 and 2016, the US Army conducted a series of large-scale chlorine releases at the Dugway Proving Ground in Utah, known as the Jack Rabbit II trials. The purpose of these experiments was to improve our understanding of pressure-liquefied chlorine releases and atmospheric dispersion, and provide useful practical knowledge for emergency responders. The tests conducted in 2015 featured a grid of Conex shipping containers around the release point to simulate a mock urban array of buildings, while the tests in 2016 studied different release orientations and culminated in the full discharge of a 20-ton chlorine road tanker.Before, during and after these experiments, a group of dispersion modelling experts from around the world collaborated in simulating the tests to help configure the experiments and evaluate the performance of models. This paper presents the progress made in that modelling activity by two of the groups involved: the UK Health and Safety Executive (HSE) and the US National Center for Atmospheric Research (NCAR). The models tested by HSE and NCAR range in complexity from integral models that can be run quickly for emergency response to Computational Fluid Dynamics (CFD) models that require days of computing time. This paper summarizes these groups' analysis of the 2015 experimental data and initial model findings, and outlines future research directions.The discharge model predictions by HSE show that meta-stable models tended to over-predict the measured release rate from the chlorine tank, whilst flashing models under-predicted the release rate. CFD simulations of the near-field flow behavior show that the chlorine cloud was initially directed laterally, out of the sides of the mock urban array, due to the alignment of Conex containers. The two integral models tested by HSE (DRIFT and PHAST) provide best agreement with the downwind concentration data when they take into account the rainout of liquid from the impinging two-phase jet. The two models tend to over-predict concentrations slightly, but many of the measurements may have under-recorded the peak concentrations, due to sensors saturating and the clouds bypassing sensors. The newly-developed NCAR integral model accounts for the transition from momentum to buoyancy-dominated behavior and shows promising agreement with the CFD results and measured concentrations. In addition, it reproduces the observed −5/3 power law decay in concentration at large distances.Efforts are continuing on analysis of the Jack Rabbit II experiments and a collaborative international model inter-comparison exercise is currently underway. Additional papers by the coordinators of that exercise and other experts should be forthcoming. The Jack Rabbit II dataset will no doubt be used for decades to come as a seminal test case for validating flashing jet and dense gas dispersion models.

Fine Structure, Instabilities, and Turbulence in the Lower Atmosphere: High-Resolution In Situ Slant-Path Measurements with the DataHawk UAV and Comparisons with Numerical Modeling

AbstractA new platform for high-resolution in situ measurements in the lower troposphere is described and its capabilities are demonstrated. The platform is the small GPS-controlled DataHawk unmanned aerial system (UAS), and measurements were performed under stratified atmospheric conditions at Dugway Proving Ground, Utah, on 11 October 2012. The measurements included spiraling vertical profiles of temperature and horizontal wind vectors, from which the potential temperature θ, mechanical energy dissipation rate ε, Brunt–Väsälä frequency N, temperature structure parameter CT2, Thorpe and Ozmidov scales LT and LO, and Richardson number Ri were inferred. Profiles of these quantities from ~50 to 400 m reveal apparent gravity wave modulation at larger scales, persistent sheet-and-layer structures at scales of ~30–100 m, and several layers exhibiting significant correlations of large ε, CT2, LT, and small Ri. Smaller-scale flow features suggest local gravity waves and Kelvin–Helmholtz instabilities exhibiting strong correlations, yielding significant vertical displacements and inducing turbulence and mixing at smaller scales. Comparisons of these results with a direct numerical simulation (DNS) of similar multiscale dynamics indicate close agreement between measured and modeled layer character and evolution, small-scale dynamics, and turbulence intensities. In particular, a detailed examination of the potential biases in inferred quantities and/or misinterpretation of the underlying dynamics as a result of the specific DataHawk sampling trajectory is carried out using virtual sampling paths through the DNS and comparing these with the DataHawk measurements.