Abstract. The Asian summer monsoon has a strong convectional component with which aerosols are able to be lifted up into the lower stratosphere. Due to usually long lifetimes and long-range transport aerosols remain there much longer than in the troposphere and are also able to be advected around the globe. Our aim of this study is a synergy between simulations by Chemical Lagrangian Model of the Stratosphere (CLaMS) and KARL (Koldewey Aerosol Raman Lidar) at AWIPEV, Ny-Ålesund in the Arctic, by comparing CLaMS results with exemplary days of lidar measurements as well as analyzing the stratospheric aerosol background. We use global three-dimensional Lagrangian transport simulations including surface origin tracers as well as back trajectories to identify source regions of the aerosol particles measured over Ny-Ålesund. We analyzed lidar data for the year 2021 and found the stratosphere generally clear, without obvious aerosol layers from volcanic eruptions or biomass burnings. Still an obvious annual cycle of the backscatter coefficient with higher values in late summer to autumn and lower values in late winter has been found. Results from CLaMS model simulations indicate that from late summer to early autumn filaments with high fractions of air which originate in South Asia – one of the most polluted regions in the world – reach the Arctic at altitudes between 360 and 380 K potential temperature. We found a coinciding measurement between the overpass of such a filament and lidar observations, and we estimated that backscatter and depolarization increased by roughly 15 % during this event compared to the background aerosol concentration. Hence we demonstrate that the Asian summer monsoon is a weak but measurable source for Arctic stratospheric aerosol in late summer to early autumn.

中文翻译：

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亚洲夏季季风在北极平流层气溶胶预算中发挥作用吗？


摘要。亚洲夏季季风具有强烈的对流成分，气溶胶能够被提升到平流层下部。由于气溶胶通常寿命长且远距离输送，因此气溶胶在那里停留的时间比在对流层中的时间长得多，并且还能够在全球范围内平流传播。我们这项研究的目的是通过将 CLaMS 结果与激光雷达测量的示例天数进行比较，实现北极纽约奥勒松 AWIPEV 的平流层化学拉格朗日模型 (CLaMS) 和 KARL（科德威气溶胶拉曼激光雷达）模拟之间的协同作用分析平流层气溶胶背景。我们使用全球三维拉格朗日输运模拟（包括表面起源示踪剂和反向轨迹）来识别在尼奥勒松上空测量的气溶胶颗粒的源区域。我们分析了 2021 年的激光雷达数据，发现平流层总体晴朗，没有明显的火山喷发或生物质燃烧造成的气溶胶层。后向散射系数仍存在明显的年周期变化，夏末至秋季值较高，冬末值较低。 CLaMS 模型模拟的结果表明，从夏末到初秋，源自南亚（世界上污染最严重的地区之一）的空气含量高的细丝在潜在温度为 360 至 380°K 的海拔高度处到达北极。我们发现这种灯丝的立交桥和激光雷达观测之间存在重合的测量结果，并且我们估计，与背景气溶胶浓度相比，在该事件期间反向散射和去极化增加了大约 15%。 因此，我们证明亚洲夏季季风是夏末至初秋北极平流层气溶胶的一个微弱但可测量的来源。