title: [Distribution and air-sea fluxes of methane in the Yellow Sea and the East China Sea in the spring].
abstract: A survey was carried out in the Yellow Sea and the East China Sea from March 17 to April 06 of 2011. Dissolved CH4 in various depths were measured and sea-to-air fluxes were estimated. Methane concentrations in surface and bottom waters ranged between 2.39-29.67 nmol x L(-1) and 2.63-30.63 nmol x L(-1), respectively. Methane concentrations in bottom waters were slightly higher than those in surface waters, suggesting the existence of methane source in bottom waters or sediments. The horizontal distribution of dissolved CH4 showed a decrease from the river mouth to the open sea, and was influenced by the freshwater discharge and the Kuroshio intrusion. Surface methane saturations ranged from 93%-1 038%. Sea to air CH4 fluxes were (2.85 +/- 5.11) micromol x (m2 x d)(-1) (5.18 +/- 9.99) micromol x (m2 x d)(-1) respectively, calculated using the Liss and Merlivat (LM86), the Wanninkhof (W92) relationships and in situ wind speeds, and estimated emission rates of methane from the East China Sea and the Yellow Sea range from 7.05 x 10(-2) - 12.0 x 10(-2) Tg x a(-1) and 1.17 x 10(-2) - 2.20 x 10(-2) Tg x a(-1), respectively. The Yellow Sea and East China Sea are the net sources of atmospheric methane in the spring.
authors.affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China. xingpeng212@163.com
authors.forename: Xing-Peng
authors.initials: XP
authors.lastname: Cao
authors.forename: Gui-Ling
authors.initials: GL
authors.lastname: Zhang
authors.forename: Xiao
authors.initials: X
authors.lastname: Ma
authors.forename: Guo-Ling
authors.initials: GL
authors.lastname: Zhang
authors.forename: Su-Mei
authors.initials: SM
authors.lastname: Liu
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002681:China; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D008697:Methane / Q000032:analysis*; D009792:Oceans and Seas; D012621:Seasons; D012623:Seawater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D014874:Water Pollutants, Chemical; D008697:Methane