Geoscience Reference
In-Depth Information
CH
4
,NH
3
, HCN, methanol, acidic acid, acetol, and others. The knowledge of the
volumes of emitted aerosols is important to study the consequences of their impact
on the radiation budget and dynamics of ecosystems of land and the World Ocean.
Christian et al. (2003) found out several new components appearing in burning the
African fuels; they are chemically active substances which can take an active part in
oxidation reactions. These substances include acetaldehyde, phenol, acetol,
glycolaldehyde, methylvinilether, furan, acetone, acetonitrile, propylene-nitrile and
propanenitrile. Emissions of chemically active oxidizing volatile organic com-
pounds in the
fires in African savannas and in Indonesia constitute 70 and 77 % of
all emitted aerosols, respectively.
Many uncertainties appear in studies of the impact of biomass burning on the
ozone layer, though there is evidence of this impact. In the period 21 January
14
February 1999, when huge amounts of biomass were burned on the western coast of
Africa, sonde measurements of the tropospheric ozone content were carried out on
the scienti
-
c ship along the route from Norfolk (37
o
N, 76
o
W) to Cape Town (34
°
S,
22
rmed: the tropospheric ozone and its pre-
cursors connected with biomass burning were concentrated in the lower troposphere
mainly because of the absence of an intensive convection on land. In the layer
1,000
°
E). The earlier conclusion was con
799 hPa there was a wind-driven transport of ozone and its precursors
towards the equator or west. On the other hand, the effect of the upward adiabatic
motions connected with the diurnal change of the processes in the west-African
planetary atmospheric boundary layer (ABL), could determine the vertical transport
of ozone and its precursors to the free atmosphere over the marine ABL. Besides,
lightning strokes in the regions of South Africa, Central Africa, and meso-scale
convective systems of the Gulf of Guinea could cause an increase of tropospheric
ozone concentration in the middle and upper troposphere of the tropical Atlantic
Ocean in the Southern Hemisphere. At the same time, a decrease of the ozone
content called the
-
“
ozone paradox
”
was recorded in the tropical Atlantic Ocean in
the Southern Hemisphere.
8.4.4 Wild
res and Carbon Cycle
Wood remains (WR) are an important component of all forest ecosystems, since
they affect the nutrients
'
cycle, humus formation, carbon storage, frequency of
occurrence of forest
fires, water cycle, and are a natural habitat for heterotrophic and
autotrophic organisms. Usually the presence of dead trees and WR is left out of
account in the estimation of carbon budgets, though the importance of these carbon
reservoirs as boreal supplies of carbon has recently attracted attention.
Bond-Lamberty et al. (2003) studied the distribution and respiration dynamics of
wood remains under conditions of chronological succession in the
fires of boreal
forests consisting mainly of black spruce, in the northern part of the Manitoba
Province (Canada). The considered chronological succession included seven forest
stands that suffered
fires in the period 1870
1998. Each of the forest stands was a
-
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