Long-range transport of Asian dust to the Arctic: identification of transport pathways, evolution of aerosol optical properties, and impact assessment on surface albedo changes

[摘要] Airborne dust is one of the most important natural aerosols; it has variousenvironmental impacts on air quality, ocean fertilization, and the globalclimate change. Asian dust, representing one of the major dust sources inthe world, has been widely studied due to its long-range transportcapability. However, its transport to the Arctic has been less investigated.In this study, two typical transport routes were identified based on therecorded dust events in China during 2011–2015. Accordingly, two specificAsian dust long-range transport events were selected and compared, i.e., oneobserved at Barrow, Alaska (traveled mostly over lands within 6–7 d), andthe other one observed at Alert, Canada (traveled mostly over oceans within7–8 d). The transport routes of the two dust events had beencross-validated by using air mass trajectory modeling, meteorologyreanalysis data, ground-based aerosol columnar and profiling observations,and spaceborne remote sensing. It was found that different transport routesto the Arctic had divergent effects on the evolution of aerosol properties,revealing different mixing extents between dust, anthropogenic particles,smoke, and sea salts. Based on the Snow, Ice, and Aerosol Radiative (SNICAR) model, thealbedo simulation indicated that dust and elemental carbon together reducedthe surface albedo by 0.35 % to 2.63 % compared to the pure snowcondition. This study implied that the dust long-range transport from China to theArctic was ubiquitous and may be a potential contributor to the Arcticregional climate.

[学科分类] 医学（综合）