Spatial distribution of marine atmospheric isoprene in the Southern Hemisphere: Role of atmospheric removal capacity

• Published in: Atmospheric Environment
• Main Authors: Yu, Xiawei, Zhang, Yanli, Jin, Ruilin, Chai, Zhangyan, Hu, Qihou, Yu, Juan, Xing, Jie, Zhang, Lulu, Kang, Hui, Zhang, Yanxu, Wang, Xinming, Xie, Zhouqing
• Format: Report
• Language: English
• Published: PERGAMON-ELSEVIER SCIENCE LTD 2023
• Subjects: Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Isoprene; Spatial distribution; Influencing factors; Marine emission capacity; Atmospheric removal capacity; Environmental Sciences; NONMETHANE HYDROCARBONS; BOUNDARY-LAYER; ARCTIC-OCEAN; DIMETHYL SULFIDE; SURFACE OCEAN; INDIAN-OCEAN; NEW-MODEL; EMISSIONS; OXIDATION; SEA; Arctic Ocean; Phytoplankton; Southern Ocean
• Online Access: http://ir.gig.ac.cn/handle/344008/70796; https://doi.org/10.1016/j.atmosenv.2022.119414

Isoprene is important to the formation of secondary organic aerosols and can change the atmospheric oxidation capacity in the remote marine environment. However, the influencing factors of marine atmospheric isoprene are still unclear. Here, we report observed atmospheric isoprene in ambient air along three cruises path from the Arctic Ocean to the Southern Ocean. The levels of isoprene ranged from not detected (ND) to 452 pptv, with an average value of 48 +/- 81 pptv, with large variability. A negative correlation was found between isoprene and latitude (r =-0.40, p < 0.01). The spatial distributions of isoprene flux from oceanic phytoplankton by the modelled results were different from those of observed atmospheric isoprene. The observed isoprene concen-tration was 2-3 orders of magnitude higher than the model estimation. Environmental variables such as tem-perature, wind speed (WS), sea surface temperature (SST), salinity and atmospheric removal capacity can influence the distribution of isoprene. At latitudes north of 60<degrees>S, the marine emission capacity was relatively important and contributed 45.06%. Atmospheric removal capacity was the most important factor for atmo-spheric isoprene, contributing 55.05% to the concentration of atmospheric isoprene in latitudes south of 60 degrees S. Low atmospheric oxidation capacity and wind speed cause high atmospheric isoprene in the Southern Ocean in summer and will eventually affect secondary organic aerosol concentrations.