Abstract：
South and Southeast Asia (SSA) emitted black carbon (BC) exerts potential effects on glacier and snow melting and regional climate change in the Tibetan Plateau. In this study, online BC measurements were conducted for 1 year at a remote village located at the terminus of the Mingyong Glacier below the Meili Snow Mountains. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) was used to investigate the contribution and potential effect of SSA-emitted BC. In addition, variations in the light absorption characteristics of BC and brown carbon (BrC) were examined. The results indicated that the annual mean concentration of BC was 415 ± 372 ngm-3, with the highest concentration observed in April (monthly mean: 930 ± 484 ngm-3). BC exhibited a similar diurnal variation throughout the year, with two peaks observed in the morning (from 8:00 to 9:00 AM) and in the afternoon (from 4:00 to 5:00 PM), with even lower values at nighttime. At a short wavelength of 370 nm, the absorption coefficient (babs) reached its maximum value, and the majority of babs values were < 20 Mm-1, indicating that the atmosphere was not overloaded with BC. At the same wavelength, BrC substantially contributed to babs, with an annual mean of 25.2 % ± 12.8 %. SSA was the largest contributor of BC (annual mean: 51.1 %) in the study area, particularly in spring (65.6 %). However, its contributions reached 20.2 % in summer, indicating non-negligible emissions from activities in other regions. In the atmosphere, the SSA BC-induced radiative forcing (RF) over the study region was positive. While at the near surface, the RF exhibited a significant seasonal variation, with the larger RF values occurring in winter and spring. Overall, our findings highlight the importance of controlling BC emissions from SSA to protect the Tibetan Plateau against pollution-related glacier and snow cover melting.
摘要：
南亚和东南亚（SSA）排放的黑碳（BC）对青藏高原的冰川和积雪融化以及区域气候变化具有潜在影响。在这项研究中,在线BC测量是在梅里雪山下方明永冰川终点的一个偏远村庄进行的，为期一年。天气研究和预报模型与化学（WRF-Chem）相结合用于研究SSA排放的BC的贡献和潜在影响。此外,研究了BC和棕碳（BrC）的光吸收特性的变化。结果表明，BC的年平均浓度为415±372ngm-3，在4月观察到最高浓度（月平均：930±484ngm-3）。BC全年表现出类似的昼夜变化，在上午（从8:00到9:00）和下午（从16:00到17:00）观察到两个高峰，在夜间甚至更低的价值。在370纳米的短波长下，吸收系数（babs）达到最大值，大多数babs值<20Mm-1，表明大气中没有BC超载。在相同的波长下，BRC对婴儿有很大贡献，年平均值为25.2%±12.8%。SSA是研究区域中BC的最大贡献者（年平均值：51.1％），特别是在春季（65.6%）。然而,它的贡献在夏季达到20.2%，表明其他地区活动产生的不可忽视的排放。在大气中,研究区域的SSABC诱导的辐射强迫（RF）为阳性。在近地表，RF表现出显著的季节性变化，较大的RF值出现在冬季和春季。总的来说,我们的发现强调了控制SSA的BC排放以保护青藏高原免受与污染有关的冰川和积雪融化的重要性。
