Chemistry Reference
In-Depth Information
Fig. 7 (a) Trajectories representing the clusters for an eastern German region (b) relative
contributions to PM10 levels (
bars
) and mean PM10 concentrations (
markers
) for rural (
green
,
stars
), urban (
blue
,
triangles
) and traffic (
red
,
diamonds
) sites per trajectory cluster (from [
28
] with
permission from authors and publisher)
This result is in line with CTM model calculations of the contribution of inland
and foreign emissions to PM levels in Germany [
29
]. According to that study,
regional PM10 levels would decrease to less than 10
m
g/m if only the German
emission sources are considered, and below of ca. 20
g/m in agglomeration areas
(Fig.
8a
). This corresponds (Fig.
8c
) to ca. 40% and ca. 60%, respectively, of the
PM10 levels modelled in a base run including all emissions. The complementary
impact of non-German emissions on the PM level and their relative share to the base
run levels are shown in Fig.
8b
, d, respectively.
m
3.2.2
“Lenschow” Studies
The source apportionment approach according to the full approach proposed by
Lenschow et al. in 2001 has not very often been carried out in Germany despite
being a rather straightforward method. Following the first original analysis a more
extended study based on comparisons of several traffic influenced, urban background
and rural background sites in and around Berlin was carried out for the years 2001/
2002 [
32
]. For a traffic site in Dresden a 1 year study on the chemical composition of
various PM size fractions was made which included short comparative measurements
with urban and rural sites. A Lenschow analysis was carried out based on the results
of these campaigns [
45
]. A third study used chemical composition data obtained
during the cold season in the region of Frankfurt [
40
]. The source apportionment
results obtained for the hot-spot (traffic) sites are summarised in Table
2
. A similar
overall contribution of 40-50% by traffic emissions is apparent. For the other source
categories more variable shares were obtained. This, on the one hand, reflects the
different measurement periods (higher shares for domestic heating in the cold season
campaign in Frankfurt a. M.), and, on the other hand, the different scope of regional
and local emission registers.
