Isopleth concentration lines

Isopleth A line of constant vapor concentration downwind from a release. 

A typical reqmrement is to determine the cloud boundaiy at a fixed concentration. These boundaries, or lines, are called isopleths. The... 

Pollutant concentration maps may be constructed as shown in Fig. 15-5 (14). In this example, elevated levels of ambient particulate matter are associated with population centers. For a given geographic area, isopleths, lines showing equal concentrations of a pollutant, are drawn on a map. Regions of high concentration are quickly identified. Further action may be taken to determine the cause, such as review of emission inventories of additional sampling. 

Figure 4 shows an isomap of the lead pollution in the first smelter area of the Dallas Lead Study. The round symbol in the center represents the smelter. The lines are isopleths of lead in soil in pg/g. Note the cluster of closed isopleths encircling the smelter. The large number of concentric isopleths encircling the smelter shows a steep gradient or rapid change in a short distance between a low (200 ig/g) outside and a high (3,000 pg/g) inside. 

In each figure, the regional UTM coordinates are given and excluded areas are shown. Heavy lines are county boundaries. The plotted sources are ED/BG centroids their size is roughly proportional to the district s population. Coded isopleths of concentration or hazard are presented, and the code values are listed to the right. 

Frequently the cloud boundary defined by a fixed concentration is required. The line connecting points of equal concentration around the cloud boundary is called an isopleth. For a specified concentration (C) the isopleths at ground level are determined by dividing the equation for the centerline concentration (Equation 5-40) by the equation for the general ground-level concentration (Equation 5-39). This equation is solved directly for y ... 

Output displays will be required to bring the abstract aspects of voluminous output data into some form that appeals to the experience of the user. Isopleth maps are useful, as are three-dimensional isometric plots like SYMVu, produced by Harvard University. Printer plots of concentration maps will undoubtedly enjoy an even greater application, because of the common availability of line printers or teletypewriters as output devices. Examples of these techniques are symap and grid, both produced by Harvard University. 

Finally, on a still larger scale, about the scale of a small town, there will be isopleths (lines of constant concentration) of our tracer that look something like those given in the last illustration of Figure 6.15. If enough particle and lense effects have occurred with an apparent randomness to our tracer cloud, then the cloud disperses in a manner similar to that illustrated. 

Figure 5 Isopleths showing the concentration of HO2 + RO2 (ppt) as a function of VOC (ppbC) and NO c (ppb) for mean summer daytime meteorology and clear skies, based on zero-dimensional calculations shown in Milford et al. (1994) (reproduced by permission of American Geophysical Union from J. Geophys. Res. 1994, 99, 3533-3542) and in Figure 3. The isopleths represent 2 ppt (dashed line) and 20, 40, 60, 80, and 100 ppt (solid lines).

The ozone ridge line identifies the maximum 03 concentration that can be achieved at a given VOC level, allowing the NO level to vary. If the NO level is either increased or decreased relative to that at the ridge line, the maximum amount of 03 produced at that VOC level will decrease. The region of the ozone isopleth plot below the ridge line is what... 

Multiple results, such as weekly data in an annual report, can be tabulated as the mean value with its standard deviation or values of the mean, highest, and lowest value by location and sample medium. Additional information should be provided if elevated radionuclide levels occur at specific times or locations. Patterns of changing radionuclide concentrations can be presented as time-line graphs. Spatial patterns of radionuclide concentrations can be presented as maps with concentration isopleths, which indicate the points at which each radionuclide has a specified constant concentration. 

Isopleth Lines of constant concentration in a diagram or plot of a mathematical model of concentration versus distance. 

Perform the calculations and generate downstream concentrations, including lines of constant concentration (isopleths) resulting from... 

With the pre-selected polymer concentrations, isobaric critical lines can be constructed from the isopleths in Figure 1. The thus obtained critical lines from 100 bar to 800 bar, respectively, show in Figure 2 on a T- plane. In Figure 2 the coexistence boundaries are described on a T- plane at the indicated pressures (bar)(the boundary under 1 bar was extrapolated from Figure 1). The shape of the coexistence curve depends only slightly on pressure, which can be recognized by comparing the curve at lOObar with the curve at 800 bar, and this system shows that it is an upper critical solution temperature (UCST) behavior system... 

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