Characterization and traceability of black carbon aerosol mass concentration on the Pamir Plateau
As a key region in the construction of"China-Pakistan Economic Corridor",the Pamir Plateau is adja-cent to the arid and semi-arid desert zone,which is seriously desertified and prone to sand.In order to investigate the concentration variation characteristics and potential source areas of black carbon(BC)on the Pamir Plateau at different time scales,continuous observations of BC concentrations on the Pamir Plateau from March 2019 to December 2022 were conducted using the AE-33 black carbon monitor,and cluster analysis,potential source contribution factor analysis(PSCF)and concentration weight trajectory analysis(CWT)were performed on BC during the observation period using the HYPSLIT model.The results show that:(1)The BC concentration from March 2019 to December 2022 shows a fluctuating decreasing trend with low BC emissions and high air cleanli-ness.The daily changes show a bimodal distribution with peaks occurring at 09:00 am and 20:00 pm,respectively.(2)BC concentrations show a seasonal pattern in winter(713.33±126.16 ng·m-3)＞autumn(648.00±70.23 ng·m-3)＞spring(403.33±30.64 ng·m-3)＞summer(390.67±32.89 ng·m-3),with offshore pollution emissions and seasonal changes in the natural environment being the main reason for the variation of BC concentration.(3)BC concen-tration is correlated with meteorological element temperature(r=-0.522),wind speed(r=-0.427)and humidity(r=0.345)at a high level of significance.(4)There is significant seasonal variation in BC concentrations on the Pamir Plateau,which is affected by long distance transport.Potential sources are concentrated in northern Paki-stan and Kashmir in spring(WPSCF＞0.6,WCWT＞600 ng·m-3);Potential sources are concentrated in Surkhandarya of Uzbekistan,Dushanbe and Gorno-Badakhshan Autonomous Oblasts of Tajikistan in autumn(WPSCF＞0.7,WCWT＞800 ng·m-3).There are obvious spatial and temporal concentration variations of BC on the Pamir Plateau,and its potential source are mainly from outside the country due to meteorological factors and long-distance transport.
black carbonPamir Plateaubackward trajectory modelpotential source
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NSTL
万方数据
