【摘要】 根据2010年4—5月国家基金委南海多学科综合航次在南海中部和北部的调查资料,利用抽真空气相色谱法测定海水中溶存甲烷浓度,分析了该海区上层海水中溶存甲烷的浓度、饱和度及海气交换通量。南海中部和北部表层海水中溶存甲烷浓度范围为1.15—5.6nmol.L 1,平均值为2.2nmol.L 1,饱和度范围为59.7%—298.8%,59%站位的溶存甲烷处于过饱和状态。甲烷海气交换通量范围分别为17.7—61.3μmol.m 2.d 1(根据LM-86方程计算)和27.9—119.6μmol.m 2.d 1(根据W-92方程计算)。南海是大气中甲烷的来源之一,年甲烷辐射量估算值为2.7×10 2—4.0×10 2Tg.a 1。更多还原

【Abstract】 Dissolved methane concentration,saturation and the sea-to-air transfer flux of dissolved methane in the upper seawater of the central and northern South China Sea(SCS) were analyzed using data from a comprehensive multidisciplinary voyage to this sea from April to May 2010.Dissolved methane from seawater was determined by gas chromatography(GC) through vacuum pumping.The methane concentrations of the surface seawater in the central and northern SCS varied from 1.15 to 5.6 nmol.L 1,with an average value of 2.2 nmol.L 1.The methane saturation varied from 59.7% to 298.8%,with oversaturated methane found at 59% of the sites.The sea-to-air transfer flux of methane varied from 17.7 to 61.3 μmol.m 2.d 1(calculated by the LM-86 equation) and from 27.9 to 119.6 μmol.m 2.d 1(calculated by the W-92 equation).The SCS is one of the sources of atmospheric methane with an estimated value of annual methane radiant quantity from 2.7×10 2 to 4.0×10 2Tg.a 1.更多还原