Environmental Engineering Reference
In-Depth Information
SOA [
µ
g/m
3
] [6 trees] (20. - 30. Jul. 2005)
SOA [
µ
g/m
3
] [126 trees] (20. - 30. Jul. 2005)
a)
b)
69N
66N
63N
60N
57N
54N
51N
48N
45N
42N
39N
369N
10W
69N
66N
63N
60N
57N
54N
51N
48N
45N
42N
39N
36N
4
3
3
2
2
1
1
0
5W
0
5E
10E
15E
20E
25E
30E
35E
10W
5W
0
5E
10E
15E
20E
25E
30E
35E
BSOA [tot-SOA] [%] (6 trees)
BSOA [tot-SOA] [%] (126 trees)
69N
66N
63N
60N
57N
54N
51N
48N
45N
42N
39N
36N
10W
69N
66N
63N
60N
57N
54N
51N
48N
45N
42N
39N
36N
10W
c)
d)
95
90
85
80
75
70
60
50
45
30
5W
0
5E
10E
15E
20E
25E
30E
35E
5W
0
5E
10E
15E
20E
25E
30E
35E
Fig. 1.
Secondary organic aerosols. Average values over time-period from 20 to 30 July 2005
without (a) and with (b) detailed tree information in µg/m³. Biogenic to total secondary organic
aerosol ratio expressed in percentages without (c) and with (d) detailed tree information
Sweden, Finland and North-Western-Russia, RCG with detailed tree information
simulates considerably higher values of SOA over Austria (ca. 2 µg/m³), Balkans
(ca. 1.5 µg/m³), Spain and Italy (up to 1 µg/m³) than without the detailed tree
inventory. This becomes even more evident if the only biogenic part of the total
secondary organic aerosol, with terpenes as gaseous precursors, is considered
(
Fig. 1c, d)
. Over 70% of total SOA concentrations stem from biogenic terpene
emissions over Scandinavia, Russia, Switzerland, Austria, Balkans and Southern
France, when only surrogate tree information is used. This percentage becomes
considerably higher when detailed tree information is used, especially over Spain,
the Alps and Corsica. During hot summer days RCG simulations with detailed
biogenic emissions give higher ozone and secondary organic aerosol values than
with emission estimates based only on aggregated forest information. Especially
in Southern and Central Europe Secondary organic aerosols with origin in bio-
genic emissions may be determinant in reaching dangerous levels of ozone as well
as of PM10.
Figure 2a
shows the contribution to the total Ozone concentration of the RCG
CBIV-Chemistry Module over a chosen domain in central Spain. Especially on 21
and 22 July 2005 RCG with the detailed biogenic emission estimates gives almost
double ozone-production values than RCG with biogenic emissions derived from
the aggregated forest information. Comparisons with observations show that this
3
higher contribution to the overall O concentration brings RCG with 126 tree species
