Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
Department of Earth and Environmental Science, Rutgers University, Newark, NJ 07102, USA.
Sci Total Environ. 2021 Mar 25;762:143089. doi: 10.1016/j.scitotenv.2020.143089. Epub 2020 Oct 27.
Biogenic organic aerosols are important components of atmospheric organic aerosols and play vital roles in atmospheric chemistry, global climate, and biogeochemical cycles of carbon. However, studies on biogenic organic aerosols in the vast regions of the Southern Ocean and over the coastal waters of the Antarctic, especially Antarctic Peninsula, are still extremely limited. To understand the concentrations, molecular composition and seasonality of biogenic organic aerosols in Antarctica, atmospheric aerosols were collected at the Palmer Station on the west Antarctic Peninsula experiencing dramatic climate warming. Molecular marker compounds of fungal spores and secondary organic aerosols formed from the photooxidation of isoprene and monoterpene were analyzed using gas chromatography/mass spectrometry. Concentrations of sugar alcohols and biogenic SOA tracers both presented seasonal patterns with higher average concentrations in summer (90.7 and 122 pg m) than in winter (8.88 and 57.2 pg m). Sugar alcohols and biogenic SOA tracers were predominated by mannitol and isoprene oxidation products. Relative contributions of fungal-spore organic carbon (OC), isoprene-derived secondary OC (SOC) and monoterpene-derived SOC estimated with tracer-based methods were 26.2%, 55.6% and 18.2%, respectively. The observed seasonality of total biogenic SOA and some molecular species at the Antarctic Peninsula was further supported by the results from the global model CESM/IMPACT. Model results also suggest higher biogenic SOA in East Antarctica than that in West Antarctica, which is attributed to the influence of vertical atmospheric circulation. Our results of air-mass trajectory indicate the potential influence of marine emissions on the biogenic organic aerosols over the Antarctic Peninsula.
生物成因有机气溶胶是大气有机气溶胶的重要组成部分，在大气化学、全球气候和碳的生物地球化学循环中起着至关重要的作用。然而，对南大洋广阔区域和南极沿海地区，特别是南极半岛的生物成因有机气溶胶的研究仍然极其有限。为了了解南极洲的生物成因有机气溶胶的浓度、分子组成和季节性，在经历剧烈气候变暖的西南极半岛的帕尔默站采集了大气气溶胶。利用气相色谱/质谱联用仪分析了真菌孢子的分子标记化合物和异戊二烯和单萜光氧化形成的二次有机气溶胶。糖醇和生物成因 SOA 示踪剂的浓度均呈现季节性模式，夏季（90.7 和 122 pg m）的平均浓度高于冬季（8.88 和 57.2 pg m）。糖醇和生物成因 SOA 示踪剂主要由甘露醇和异戊二烯氧化产物组成。利用示踪剂法估算的真菌孢子有机碳（OC）、异戊二烯衍生的二次 OC（SOC）和单萜衍生的 SOC 的相对贡献分别为 26.2%、55.6%和 18.2%。基于全球模式 CESM/IMPACT 的结果进一步支持了南极半岛总生物成因 SOA 和一些分子物种的季节性观测。模型结果还表明，东南极的生物成因 SOA 高于西南极，这归因于垂直大气环流的影响。我们的气团轨迹结果表明，海洋排放可能对南极半岛的生物成因有机气溶胶产生影响。
