Environmental Engineering Reference
In-Depth Information
Figure 5.9
An estimate of the mean vertical profile of the concentration of anthropogenic aerosol mass in the
high Arctic during March and April
Source:
After Barrie (1986)
Note:
C(H)/C(0) is the concentration at a specific altitude divided by the concentration at the surface.
Arctic Haze includes a variety of
components—from dust and soot particles to
pesticides—but the most common constituent is
sulphate particles. Their presence at increasingly
high concentrations not only in the Arctic, but
in other remote areas, such as the republic of
Georgia in the former Soviet Union, far removed
from major pollution sources, is also causing
concern (Shaw 1987), because of their ability to
disrupt the flow of energy in the atmosphere and
because of the contribution they make to acid
precipitation (see Chapter 4).
Providing a direct contrast to these
developments are studies which claim that it is
not possible to detect any human imprint in
changing atmospheric turbidity. Observations in
the Antarctic in the mid-1960s revealed no
significant change in aerosol levels in that area
between 1950 and 1966 (Fischer 1967). Data
from Mauna Loa, where Bryson and Peterson
(1968) claimed to find evidence of rising levels
of turbidity induced by human activities, were
re-interpreted to show that there was no evidence
that human activity affected atmospheric
turbidity on a global scale (Ellis and Pueschel
1971). The short term fluctuations revealed in
the data were associated with naturally produced
aerosols. The contradictory results from Mauna
Loa reflect differences in the scientific
interpretation of the data from one observatory.
Differences between stations are the result of a
combination of physical and human factors, and,
in reality, are only to be expected. Emission sites
are unevenly distributed. Most are located in mid-
latitudes in the northern hemisphere, and there
are great gaps—over the oceans, for example—
where little human activity takes place. The
atmospheric circulation helps to spread the
pollutants, but, since the bulk of the emissions
from anthropogenic sources are confined to the
