In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 18 ( 2018-09-27), p. 13673-13685
Abstract:
Abstract. The black carbon (BC) deposition on the ice
core at Muztagh Ata Mountain, northern Tibetan Plateau, was analyzed. Two
sets of measurements were used in this study, which included the air
samplings of BC particles during 2004–2006 and the ice core drillings of BC
deposition during 1986–1994. Two numerical models were used to analyze the
measured data. A global chemical transportation model (MOZART-4) was used to
analyze the BC transport from the source regions, and a radiative transfer
model (SNICAR) was used to study the effect of BC on snow albedo. The results
show that during 1991–1992, there was a strong spike in the BC deposition at
Muztagh Ata, suggesting that there was an unusual emission in the upward
region during this period. This high peak of BC deposition was investigated
by using the global chemical transportation model (MOZART-4). The analysis
indicated that the emissions from large Kuwait fires at the end of the first
Gulf War in 1991 caused this high peak of the BC concentrations and
deposition (about 3–4 times higher than other years) at Muztagh Ata
Mountain, suggesting that the upward BC emissions had important impacts on
this remote site located on the northern Tibetan Plateau. Thus, there is a
need to quantitatively estimate the effect of surrounding emissions on the BC
concentrations on the northern Tibetan Plateau. In this study, a
sensitivity study with
four individual BC emission regions (Central Asia, Europe, the Persian Gulf,
and South Asia) was conducted by using the MOZART-4 model. The result
suggests that during the “normal period” (non-Kuwait fires), the largest
effect was due to the Central Asia source (44 %) during the Indian
monsoon period, while during the non-monsoon period, the largest effect was
due to the South Asia source (34 %). The increase in radiative forcing
increase (RFI) due to the deposition of BC on snow was estimated by using the
radiative transfer model (SNICAR). The results show that under the fresh snow
assumption, the estimated increase in RFI ranged from 0.2 to
2.5 W m−2, while under the aged snow assumption, the estimated
increase in RFI ranged from 0.9 to 5.7 W m−2. During the Kuwait fires
period, the RFI values increased about 2–5 times higher than in the “normal
period”, suggesting a significant increase for the snow melting on the
northern Tibetan Plateau due to this fire event. This result suggests that
the variability of BC deposition at Muztagh Ata Mountain provides useful
information to study the effect of the upward BC emissions on environmental
and climate issues in the northern Tibetan Plateau. The radiative effect of
BC deposition on the snow melting provides important information regarding
the water resources in the region.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-18-13673-2018
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
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