Characteristics and emissions of isoprene and other non-methane hydrocarbons in the Northwest Pacific Ocean and responses to atmospheric aerosol deposition

Ying-Cui Wu; Xu-Xu Gao; Hong-Hai Zhang; Yong-Zheng Liu; Jian Wang; Feng Xu; Gui-Ling Zhang; Zhao-Hui Chen

doi:10.1016/j.scitotenv.2023.162808

Characteristics and emissions of isoprene and other non-methane hydrocarbons in the Northwest Pacific Ocean and responses to atmospheric aerosol deposition

Sci Total Environ. 2023 Jun 10:876:162808. doi: 10.1016/j.scitotenv.2023.162808. Epub 2023 Mar 14.

Authors

Ying-Cui Wu¹, Xu-Xu Gao², Hong-Hai Zhang³, Yong-Zheng Liu⁴, Jian Wang², Feng Xu², Gui-Ling Zhang⁵, Zhao-Hui Chen⁴

Affiliations

¹ Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
² College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
³ Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. Electronic address: honghaizhang@ouc.edu.cn.
⁴ Physical Oceanography Laboratory/Institute for advanced Ocean Study, Ocean University of China, Qingdao 266100, China.
⁵ Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China. Electronic address: guilingzhang@ouc.edu.cn.

PMID: 36921853
DOI: 10.1016/j.scitotenv.2023.162808

Abstract

Field investigations in the Northwest Pacific Ocean were carried out to determine the distributions of marine and atmospheric non-methane hydrocarbons (NMHCs), sources and environmental effects. We also conducted deck incubation experiments to investigate the effects of atmospheric aerosol deposition on NMHCs production. The marine NMHCs displayed an increasing trend from the South Equatorial Current to the Oyashio Current. The enhanced phytoplankton biomass and dissolved organic materials (DOM) content in the Kuroshio-Oyashio Extension contributed significantly to isoprene and NMHCs production compared with those in tropical waters and the North Pacific subtropical gyre. The Northwest Pacific Ocean was a significant source of atmospheric NMHCs, with average sea-to-air fluxes of 28.0 ± 38.9, 65.2 ± 73.3, 21.0 ± 26.7, 48.7 ± 62.6, 12.7 ± 15.9, 14.2 ± 16.8, and 41.7 ± 80.4 nmol m^-2 d^-1 for ethane, ethylene, propane, propylene, i-butane, n-butane, and isoprene, respectively. Influenced by seawater release and OH radical consumption, the atmospheric NMHCs apart from isoprene displayed upward trends with increasing latitude. The deck incubation showed that the addition of aerosols and acidic aerosols significantly boosted phytoplankton biomass, altered community structure, and accelerated the production of isoprene. However, the other six NMHCs showed no obvious responses to atmospheric aerosol deposition in the incubation experiments. In summary, ocean current movements and atmospheric deposition could influence the production and release of isoprene in the Northwest Pacific Ocean.

Keywords: Aerosol deposition; Isoprene; Non-methane hydrocarbons; Northwest Pacific Ocean; Sea-to-air flux.