Plume Dispersion in Four Pine Thinning Scenarios: Development of a Simple Pheromone Dispersion Model

A unique field campaign was conducted in 2004 to examine how changes in stand density may affect dispersion of insect pheromones in forest canopies. Over a 14-day period, 126 tracer tests were performed, and conditions ranged from an unthinned loblolly pine (Pinus taeda) canopy through a series of thinning scenarios with basal areas of 32.1, 23.0, and 16.1 m2ha-1. In this paper, one case study was used to visualize the nature of winds and plume diffusion. Also, a simple empirical model was developed to estimate maximum average concentration as a function of downwind distance, travel time, wind speed, and turbulence statistics at the source location. Predicted concentrations from the model were within a factor of 3 for 82.1 percent and 88.1 percent of the observed concentrations at downwind distances of 5 and 10 m, respectively. In addition, the model was used to generate a field chart to predict optimum spacing in arrays of anti-aggregation pheromone dispensers

A Tracer Investigation of Pheromone Dispersion in Lodgepole and Ponderosa Pine Forest Canopies

Tracer experiments were conducted in 2000 and 2001 to study spread of insect pheromone plumes in forest canopies. The field sites consisted of lodgepole pine (Pinus contorta) and ponderosa pine (P. ponderosa) canopies in 2000 and 2001, respectively. Ranges of temperature, wind speed, and turbulence conditions were similar in the two campaigns, and field data showed comparable variability on near-instantaneous time scales of wind speed, wind direction, and plume behavior. We developed simple empirical equations to estimate average horizontal and vertical plume spread as functions of standard turbulence statistics, downwind distance from the source, and wind speed. For horizontal plume spread, predicted dispersion coefficients were within a factor of 3, or better, for 97 percent of the observed values in the combined dataset from 2000 and 2001. Likewise, 99 percent of the predicted vertical dispersion coefficients were within a factor of 3 of the observed data

Using DUSTRAN to Simulate Fog-Oil Dispersion and Its Impacts on Local Insect Populations at Ft. Hood: Final Report

Smokes and obscurants (S&O) are important screening agents used during military training exercises on many military installations. Although the use of S&O is subject to environmental laws, the fate and effects of S&O on natural habitats are not well documented. One particular concern is the impact S&O may have on local insect populations, which can be important components of terrestrial food chains of endangered species. Fog-oil (FO) is an S&O that is of particular concern. An important part of assessing potential ecosystem impacts is the ability to predict downwind FO concentrations. This report documents the use of the comprehensive atmospheric dispersion modeling system DUST TRANsport (DUSTRAN) to simulate the downwind transport and diffusion of a hypothetical FO release on the U.S. Army installation at Ft. Hood, TX

Comparison of aromatic hydrocarbon measurements made by PTR-MS, DOAS and GC-FID during the MCMA 2003 Field Experiment

A comparison of aromatic hydrocarbon measurements is reported for the CENICA supersite in the district of Iztapalapa during the Mexico City Metropolitan Area field experiment in April 2003 (MCMA 2003). Data from three different measurement methods were compared: a Proton Transfer Reaction Mass Spectrometer (PTR-MS), long path measurements using a UV Differential Optical Absorption Spectrometer (DOAS), and Gas Chromatography-Flame Ionization analysis (GC-FID) of canister samples. The principle focus was on the comparison between PTR-MS and DOAS data. Lab tests established that the PTR-MS and DOAS calibrations were consistent for a suite of aromatic compounds including benzene, toluene, p-xylene, ethylbenzene, 1,2,4-trimethylbenzene, phenol and styrene. The point sampling measurements by the PTR-MS and GC-FID showed good correlations (r=0.6), and were in reasonable agreement for toluene, C2-alkylbenzenes and C3-alkylbenzenes. The PTR-MS benzene data were consistently high, indicating interference from ethylbenzene fragmentation for the 145 Td drift field intensity used in the experiment. Correlations between the open-path data measured at 16-m height over a 860-m path length (retroreflector in 430 m distance), and the point measurements collected at 37-m sampling height were best for benzene (r=0.61), and reasonably good for toluene, C2-alkylbenzenes, naphthalene, styrene, cresols and phenol (r>0.5). There was good agreement between DOAS and PTR-MS measurements of benzene after correction for the PTR-MS ethylbenzene interference. Mixing ratios measured by DOAS were on average a factor of 1.7 times greater than the PTR-MS data for toluene, C2-alkylbenzenes, naphthalene and styrene. The level of agreement for the toluene data displayed a modest dependence on wind direction, establishing that spatial gradients – horizontal, vertical, or both – in toluene mixing ratios were significant, and up to a factor of 2 despite the fact that all measurements were conducted above roof level. Our analysis highlights a potential problem in defining a VOC sampling strategy that is meaningful for the comparison with photochemical transport models: meaningful measurements require a spatial fetch that is comparable to the grid cell size of models, which is typically a few 10 km2. Long-path DOAS measurements inherently average over a larger spatial scale than point measurements. The spatial representativeness can be further increased if observations are conducted outside the surface roughness sublayer, which might require measurements at altitudes as high as 10 s of metres above roof level.Alexander von Humboldt-Stiftung (Feodor Lynen fellowship)Henry & Camille Dreyfus Foundation (Postdoctral Fellowship in Environmental Chemistry

Dust Plume Modeling at Fort Bliss: Full Training Scenario

The potential for air quality impacts from heavy mechanized vehicles operating in the training ranges and on the unpaved main supply routes at Fort Bliss is being investigated. The investigation uses the atmospheric modeling system DUSTRAN to simulate fugitive dust emission and dispersion from typical activities occurring on the installation. This report conveys the results of DUSTRAN simulations conducted using a “Full Training” scenario developed by Fort Bliss personnel. he Full Training scenario includes simultaneous off-road activities of two full Heavy Brigade Combat Teams (HCBTs) and one HCBT battalion on three training ranges. Simulations were conducted for the six-day period, April 25-30, 2005, using previously archived meteorological records. Simulation results are presented in the form of 24-hour average PM10 plots and peak 1-hour PM10 concentration plots, where the concentrations represent contributions resulting from the specified military vehicular activities, not total ambient PM10 concentrations. Results indicate that the highest PM10 contribution concentrations occurred on April 30 when winds were light and variable. Under such conditions, lofted particulates generated by vehicular movement stay in the area of generation and are not readily dispersed. The effect of training duration was investigated by comparing simulations with vehicular activity extending over a ten hour period (0700 to 1700 MST) with simulations where vehicular activity was compressed into a one hour period (0700 to 0800 MST). Compressing all vehicular activity into one hour led to higher peak one-hour and 24-hour average concentration contributions, often substantially higher

SPRAYTRAN 1.0 User’s Guide: A GIS-Based Atmospheric Spray Droplet Dispersion Modeling System

SPRAY TRANsport (SPRAYTRAN) is a comprehensive dispersion modeling system that is used to simulate the offsite drift of pesticides from spray applications. SPRAYTRAN functions as a console application within Environmental System Research Institute’s ArcMap Geographic Information System (Version 9.x) and integrates the widely-used, U.S. Environmental Protection Agency (EPA)-approved CALifornia PUFF (CALPUFF) dispersion model and model components to simulate longer-range transport and diffusion in variable terrain and spatially/temporally varying meteorological (e.g., wind) fields. Area sources, which are used to define spray blocks in SPRAYTRAN, are initialized using output files generated from a separate aerial-spray-application model called AGDISP (AGricultural DISPersal). The AGDISP model is used for estimating the amount of pesticide deposited to the spray block based on spraying characteristics (e.g., pesticide type, spray nozzles, and aircraft type) and then simulating the near-field (less than 300-m) drift from a single pesticide application. The fraction of pesticide remaining airborne from the AGDISP near-field simulation is then used by SPRAYTRAN for simulating longer-range (greater than 300 m) drift and deposition of the pesticide

Dust Plume Modeling at Fort Bliss: Move-Out Operations, Combat Training and Wind Erosion

The potential for air-quality impacts from heavy mechanized vehicles operating in the training ranges and on the unpaved main supply routes at Fort Bliss was investigated. This report details efforts by the staff of Pacific Northwest National Laboratory for the Fort Bliss Directorate of Environment in this investigation. Dust emission and dispersion from typical activities, including move outs and combat training, occurring on the installation were simulated using the atmospheric modeling system DUSTRAN. Major assumptions associated with designing specific modeling scenarios are summarized, and results from the simulations are presented

Final Technical Report: Development of the DUSTRAN GIS-Based Complex Terrain Model for Atmospheric Dust Dispersion

Activities at U.S. Department of Defense (DoD) training and testing ranges can be sources of dust in local and regional airsheds governed by air-quality regulations. The U.S. Department of Energy’s Pacific Northwest National Laboratory just completed a multi-year project to develop a fully tested and documented atmospheric dispersion modeling system (DUST TRANsport or DUSTRAN) to assist the DoD in addressing particulate air-quality issues at military training and testing ranges

Meteorological Integration for the Biological Warning and Incident Characterization (BWIC) System: General Guidance for BWIC Cities

The U.S. Department of Homeland Security (DHS) is responsible for developing systems to detect the release of aerosolized bioagents in urban environments. The system that accomplishes this, known as BioWatch, is a robust first-generation monitoring system. In conjunction with the BioWatch detection network, DHS has also developed a software tool for cities to use to assist in their response when a bioagent is detected. This tool, the Biological Warning and Incident Characterization (BWIC) System, will eventually be deployed to all BioWatch cities to aid in the interpretation of the public health significance of indicators from the BioWatch networks. BWIC consists of a set of integrated modules, including meteorological models, that estimate the effect of a biological agent on a city’s population once it has been detected. For the meteorological models in BWIC to successfully calculate the distribution of biological material, they must have as input accurate meteorological data, and wind fields in particular. The purpose of this document is to provide guidance for cities to use in identifying sources of good-quality local meteorological data that BWIC needs to function properly. This process of finding sources of local meteorological data, evaluating the data quality and gaps in coverage, and getting the data into BWIC, referred to as meteorological integration, is described. The good news for many cities is that meteorological measurement networks are becoming increasingly common. Most of these networks allow their data to be distributed in real time via the internet. Thus, cities will often only need to evaluate the quality of available measurements and perhaps add a modest number of stations where coverage is poor

DUSTRAN 1.0 User’s Guide: A GIS-Based Atmospheric Dust Dispersion Modeling System

The U.S. Department of Energy’s Pacific Northwest National Laboratory just completed a multi-year project to develop a fully tested and documented atmospheric dispersion modeling system (DUST TRANsport or DUSTRAN) to assist the U.S. Department of Defense in addressing particulate air quality issues at military training and testing ranges. This manual documents the DUSTRAN modeling system and includes installation instructions, a user’s guide, and detailed example tutorials