Environmental Engineering Reference
In-Depth Information
Figure 5.8
Emissions of particulate matter from selected nations: 1980-89
Source:
Based on data in World Resources Institute (1992)
of continuing anthropogenic aerosol loading of
the atmosphere. The haze is not of local origin.
It is created in mid-latitudes as atmospheric
pollution, which is subsequently carried
polewards to settle over the Arctic. It is most
pronounced between December and March, for
several reasons, including the increased emission
of pollutants at that season, the more rapid and
efficient poleward transport in winter and the
longer residence time of haze particles in the
highly stable Arctic air at that time of year (Shaw
1980). Vertical profiles through the air mass show
that the bulk of the aerosols are concentrated in
the lowest 2 km of the atmosphere (see Figure
5.9). Arctic air pollution has increased since the
mid-1950s in parallel with increased aerosol
emissions in Europe, and the net result has been
a measurable reduction in visibility and
perturbation of the regional radiation budget
(Barrie 1986).
atmosphere in the Sinai, measurements indicate a
10 per cent reduction in direct beam solar energy
up to the mid-1970s, in an area far removed from
major industrial sources (Lockwood 1979). The
fine particle content of the air above the North
Atlantic doubled between 1907 and 1969, and at
Mauna Loa in Hawaii, one estimate suggests an
increase in turbidity of 30 per cent in the ten years
between 1957 and 1967 (Bryson 1968). That
period included the Mount Agung eruption, but
the increase was still apparent after the effects of
the volcanic emissions had been removed from
the calculations (Bryson and Peterson 1968). On
the assumption that natural background levels of
atmospheric turbidity should remain constant, or
fluctuate within a very narrow range, these rising
aerosol levels were ascribed to human activities.
The development of the Arctic Haze in recent
years is generally considered to be an indication
