Abstract
In recent decades much attention has been given to the Arctic environment,
where climate change is happening rapidly. Black carbon (BC) has been shown
to be a major component of Arctic pollution that also affects the radiative
balance. In the present study, we focused on how vegetation fires that
occurred in northern Eurasia during the period of 2002–2013 influenced the
budget of BC in the Arctic. For simulating the transport of fire emissions
from northern Eurasia to the Arctic, we adopted BC fire emission estimates
developed independently by GFED3 (Global Fire Emissions Database) and FEI-NE
(Fire Emission Inventory – northern Eurasia). Both datasets were based on
fire locations and burned areas detected by MODIS (Moderate resolution
Imaging Spectroradiometer) instruments on NASA's (National Aeronautics and
Space Administration) Terra and Aqua satellites. Anthropogenic sources of BC
were adopted from the MACCity (Monitoring Atmospheric Composition and Climate
and megacity Zoom for the Environment) emission inventory.
During the 12-year period, an average area of 250 000 km2 yr−1 was
burned in northern Eurasia (FEI-NE) and the global emissions of BC ranged
between 8.0 and 9.5 Tg yr−1 (FEI-NE+MACCity). For the BC emitted in
the Northern Hemisphere (based on FEI-NE+MACCity), about 70 % originated
from anthropogenic sources and the rest from biomass burning (BB). Using the
FEI-NE+MACCity inventory, we found that 102 ± 29 kt yr−1 BC was
deposited in the Arctic (defined here as the area north of
67° N) during the 12 years simulated, which was twice as
much as when using the MACCity inventory (56 ± 8 kt yr−1). The annual
mass of BC deposited in the Arctic from all sources (FEI-NE in northern
Eurasia, MACCity elsewhere) is significantly higher by about 37 % in 2009
(78 vs. 57 kt yr−1) to 181 % in 2012 (153 vs. 54 kt yr−1),
compared to the BC deposited using just the MACCity emission inventory.
Deposition of BC in the Arctic from BB sources in the Northern Hemisphere
thus represents 68 % of the BC deposited from all BC sources (the
remaining being due to anthropogenic sources). Northern Eurasian vegetation
fires (FEI-NE) contributed 85 % (79–91 %) to the BC deposited over the
Arctic from all BB sources in the Northern Hemisphere.
We estimate that about 46 % of the BC deposited over the Arctic from
vegetation fires in northern Eurasia originated from Siberia, 6 % from
Kazakhstan, 5 % from Europe, and about 1 % from Mongolia. The remaining
42 % originated from other areas in northern Eurasia. About 42 % of the
BC released from northern Eurasian vegetation fires was deposited over the
Arctic (annual average: 17 %) during spring and summer.
Citation
ID:
136308
Ref Key:
evangeliou2016atmosphericwildfires