Multiple factors dominate the distribution of methane and its sea-to-air flux in the Bohai Sea in summer and autumn of 2014

Kunpeng Zang; Guiling Zhang; Huade Zhao; Xuemei Xu; Nan Zheng; Juying Wang; Gen Zhang

doi:10.1016/j.marpolbul.2020.111049

Multiple factors dominate the distribution of methane and its sea-to-air flux in the Bohai Sea in summer and autumn of 2014

Mar Pollut Bull. 2020 May:154:111049. doi: 10.1016/j.marpolbul.2020.111049. Epub 2020 Mar 7.

Authors

Kunpeng Zang¹, Guiling Zhang², Huade Zhao¹, Xuemei Xu¹, Nan Zheng¹, Juying Wang³, Gen Zhang⁴

Affiliations

¹ Key Laboratory for Ecological Environment in Coastal Areas, National Marine Environmental Monitoring Center, Linghe Street 42, Dalian 116023, China.
² Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Songling Road 238, Qingdao 266100, China.
³ Key Laboratory for Ecological Environment in Coastal Areas, National Marine Environmental Monitoring Center, Linghe Street 42, Dalian 116023, China. Electronic address: jywang@nmemc.org.cn.
⁴ State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, South Zhongguancun Street, Beijing 100081, China. Electronic address: zhanggen@cma.gov.cn.

PMID: 32174499
DOI: 10.1016/j.marpolbul.2020.111049

Abstract

The Bohai Sea is well-known as a source of atmospheric methane (CH₄). However, the main regulate factors of the spatiotemporal distribution of CH₄ and its sea-to-air flux remain largely unknown. In this study, the observed CH₄ concentration ranged from 4.8 to 32.7 nmol/L and 3.1 to 15.2 nmol/L in August and November of 2014, respectively. The main factors that influence the distribution of CH₄ and its sea-to-air flux were stratification, solubility, and current structure for the mid-west depression basins, the permanent well-mixed seawater column and CH₄ source strength for the centre shallow ridge zone, and the upwelling for the east depression basin, respectively. Meanwhile, wind also plays an important role in sea-to-air CH₄ flux in the study area except the centre shallow ridge zone. Upwelling made the east depression basin the most intensive source of CH₄, with a flux of 2 to 4 times higher than the other sub-regions.

Keywords: Methane; Oxygen depletion; Sea-to-air flux; Stratification; Upwelling.

MeSH terms

China
Methane*
Seasons
Seawater*
Wind

Substances

Methane