Pollution transport trajectories

Figure 5 illustrates the documented pollution transport trajectories. The majority of these pathways occur in the mid-latitude and Polar regions of both hemisphere s where stronger winds prevail. By contrast, little long-range pollution has been reported within the tropics. The most well documented long-range... 

Metal pollution transported out of eastern Asia has gained increased attention due to the high concentrations of metals being emitted from this region. Airmass trajectories from Asia result in pollutants being transported across Korea and Japan and into the Arctic Circle above North America (Okuda et al. 2006 Osterberg et al. 2008). They may also be transported to the south-east over Taiwan (Lin et al. 2005) and into the remote central Pacific (Settle and Patterson 1982). Pollution from Asia has also been found to influence the western United States (Jaffe et al. 2003, 2005) and monsoon rainfall over northern Australia (Rotstayn et al. 2007). 

Pollution plume trajectories in the Southern Hemisphere have received less attention in comparison with the Northern Hemisphere. There are few studies of long-range metal transport from Africa or South America despite the fact that these continents are known to be significant emitters of metals to the atmosphere (Fig. 4). A number of studies have been undertaken examining metal pollution accumulation in Antarctica, which being the most remote landmass from urban... 

Source apportionment studies are frequently complemented by air mass origin analyses to identify where high pollution levels or certain compounds of interest come from. For small to meso scales this can be done by, e.g. wind rose analysis, whereas long-range transport is better assessed by using back trajectories calculated by a suitable dispersion model [20],... 

Stohl A (1996) Trajectory statistics - a new method to establish source-receptor relationships of air pollutants and its application to the transport of particulate sulfate in Europe. Atmos Environ 30 579-587... 

The transport pathways of the polluted air masses can be reconstructed by trajectory analysis and elemental tracer techniques (Husain 1986 Rahn and Lowenthal 1985 Chen and Duce 1983 Lowenthal and Rahn 1985). 

According to the forward trajectories [21, 82], the pollutant puff was picked up over the area of the oil-refinery fires and moved eastward over Romania, Bulgaria, Moldavia, Ukraine, and the Black Sea. The regional transport of PAHs and PCDDs/Fs, as combustion products of PVC and VCM from Pancevo (A = 20°40, (p = 44°53 )... 

By combining trajectories at different levels, we can study the transport of air masses in the whole of the atmospheric surface layer. The variation of transport conditions in time and space is also allowed for in these computations. Because the pollutants considered here were released near ground level, we have made most of the computations for the 1,000 hPa pressure level, corresponding approximately to the lowest 200 to 300 m layer of the atmosphere. Some computations were also made for the 950 hPa pressure level, corresponding approximately to a height of 500 m. Two-dimensional (instead of three-dimensional) trajectories were considered to be sufficient due to the relatively low transport altitudes. 

Trajectories computed for later times were directed northeast, east, and southeast, into the area of the former Soviet Union. These trajectories were computed for the lowest atmospheric layer, with a height less than about 200 to 300 m. Because some pollutants may have risen to higher altitudes, we also computed the trajectories of air masses in other atmospheric layers. The transport directions at higher altitudes turn in a clockwise direction. The contribution of these pollutants to observational data in Finland is therefore small. 

To a more local and regional scale, measurements of wind profiles strongly impact on the regional forecast of the trajectories of the pollution, the calculations of transport of atmospheric trace gases, bacteria, and volcanically generated particles that, injected in... 

Three techniques have been used to determine how much sulfur pollution is transported from one region to another computer simulation, back-trajectory analysis, and trace-element analysis. Each technique has confirmed the importance of longdistance transport. 

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