Meteorological conditions

Like frequency estimates, consequence estimates can have very large uncertainties. Estimates that vary by orders of magnitude can result from (1) basic uncertainties in chemical/physical properties, (2) differences in average vs. time-dependent meteorological conditions, and/or (3) uncertainties in the release, dispersion, and effects models. Some... 

A logic model that graphically portrays the range of outcomes from the combinations of events and circumstances in an accident sequence. For example, a flammable vapor release may result in a fire, an explosion, or in no consequence depending on meteorological conditions, the degree of confinement, the presence of ignition sources, etc. These trees are often shown with the probability of each outcome at each branch of the pathway... 

Despite these limitations, mobile monitoring systems have been used to obtain useful information, such as the verification and tracking of the St. Louis, Missouri, urban plume. The measurement of a well-defined urban plume spreading northeastward from St. Louis is shown in Fig. 15-2 (7). These data were collected by a combination of instrumented aircraft and mobile vans. Cross-sectional paths were flown by the aircraft at increasing distances downwind. Meteorological conditions of low wind speed in the same direction helped to maintain this urban plume in a well-defined... 

The short-term model can then be used to estimate resulting concentrations during specific periods or to estimate concentrations for suspected adverse meteorological conditions, so that changes can be incorporated in... 

At what time of day and under what meteorological conditions is maximum ground-level pollution likely to occur at locations several kilometers inland from a shoreline industrial complex whose pollutants are released primarily from stacks of moderate height (about 40-130 m) ... 

III. METEOROLOGICAL CONDITIONS DURING HISTORIC POLLUTION EPISODES... 

II. Meteorological Conditions during Historic Pollution Episodes... 

First order parameters affecting dispersion stem from meteorological conditions. These, as much as any other consideration, determine how a stack is to be designed for air pollution control purposes. Since the operant transport mechanisms are determined by the micro-meteorological conditions, any attempt to predict ground-level pollutant concentrations is dependent on a reasonable estimate of the convective and dispersive potential of the local air. The following are meteorological conditions which need to be determined ... 

Generally, the full meteorology option should be selected. The other two options were originally included for testing purposes only, but may be useful when particular meteorological conditions are of concern. 

When using the automated distance array, SCREEN prompts the user for a minimum and maximum distance to use, which should be input in free format, i.e., separated by a comma or a space. SCREEN then calculates the maximum concentration across a range of meteorological conditions for the... 

Stagnant referring to meteorological conditions that are not conducive to atmospheric mixing. 

MESOREM Jr. Impell Corporation Becky Cropper 300 Tristate Internat l Suite 400 Lincolnshire, IL 60069 (312) 940-2090 Atmospheric release analysis system that includes back calculations of source release rates from field readings, terrain modeling, meteorological conditions modeling of multipoint dose and deposition exposures. Also provides ingestion exposure reports for atmospheric effluent pathways. 

U. = Normal average wind speed, m/s, based on local meteorological conditions... 

This chapter explores the design of stacks from the point of view of the downwind observer whose task is to determine the connection between stack design, process emissions, meteorology, and, most important, environmental effects. Stacks must be designed to specifications based on meteorological conditions and environmental air quality standards, which may be quite umelated to process requirements... 

The principal factors which must be accounted for when designing a stack for air pollution control purposes are the dispersion and transport of the pollutants and the performance criteria against which the stack will be compared. These factors include (1) air quality standards, (2) meteorological conditions, and (3) topographical peculiarities. 

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