Fertilization of the Northwest Pacific Ocean by East Asia air pollutants

Research output: Contribution to journalArticle

Authors

  • Chao Zhang
  • Akinori Ito
  • Maki Noguchi Aita
  • Xiaohong Yao
  • Qiang Chu
  • Jinhui Shi
  • Xiang Gong
  • Huiwang Gao

Colleges, School and Institutes

External organisations

  • Key Laboratory of Marine Environment and Ecology, Ministry of Education of China, Ocean University of China, Qingdao, China.
  • Yokohama Institute for Earth Sciences, JAMSTEC, Yokohama, Japan.
  • Institute of Surface Earth System Science, Tianjin University, Tianjin, China.
  • Laboratory of Environmental Protection in Water Transport Engineering, Tianjin Research Institute for Water Transport Engineering, Ministry of Transport, Tianjin, China.
  • School of Mathematics and Physics, Qingdao University of Science and Technology, Qingdao, China.
  • Laboratory for Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.

Abstract

Haze particles as a key air pollutant contain high level of toxins, which were hypothesized to inhibit phytoplankton growth when deposited to the ocean, and thus indirectly affect the climate. However, field observations have yet to provide conclusive evidence to confirm this hypothesis. Onboard microcosm experiments in the Northwest Pacific Ocean (NWPO) show that haze particles collected at the East Asia continent had an inhibition impact on phytoplankton growth only when at very high particle loading (2 mg/L). In contrast, haze particles at low and medium loadings (0.03–0.6 mg/L) stimulated phytoplankton growth and shifted phytoplankton size structure toward larger cells, primarily due to the supply of inorganic nitrogen nutrients from the particles. Model simulations showed that haze particle loading in NWPO surface seawater was usually more than an order of magnitude lower than 2 mg/L. This indicates that haze particles are unlikely to cause harm but to stimulate phytoplankton growth in the nitrogen-limited NWPO. Ocean biogeochemical modeling further shows that deposited nitrogen significantly enhanced surface ocean chlorophyll a concentration in the winter and spring of 2014. Overall, these results demonstrate that haze particles stimulate rather than inhibit primary production in the NWPO.

Details

Original languageEnglish
Pages (from-to)690-702
Number of pages13
JournalGlobal Biogeochemical Cycles
Volume33
Issue number6
Early online date6 May 2019
Publication statusPublished - 10 Jul 2019

Keywords

  • aerosol, global warming, phyotoplankton, productivity, toxicity, trace metals