冬季黄东海一氧化碳的分布和海-气通量研究

Distribution and sea-to-air flux of carbon monoxide in the Yellow Sea and East China Sea in winter

为探究海洋中一氧化碳(CO)的排放对全球碳循环的意义,于2019年冬季采用顶空法对黄海和东海CO的分布和海-气通量进行了研究.结果表明,调查海域大气中CO的体积分数为239×10^(-9)~941×10^(-9),平均值为(588±155)×10^(-9).大气中CO体积分数最高值出现在北黄海近岸站位,最低值出现在东海南部,整体呈现黄海高、东海低的特点,且表现出明显的由近岸向外海降低趋势.表层海水CO浓度为0.39~2.80 nmol·L^(-1),平均值为(1.23±0.45) nmol·L^(-1).表层海水CO浓度高值区出现在东海东部,低值区出现在东海南部,受太阳光辐射和水团影响较大.CO的垂直分布上,浓度最大值一般出现在表层,随深度增加呈现逐渐降低的趋势.表层海水中过饱和系数α为0.99~8.67,平均值为2.61±1.42. CO海-气通量的变化范围为-0.05~41.38 nmol·m^(-2)·h^(-1),平均值为(9.80±9.70) nmol·m^(-2)·h^(-1).表层海水中CO浓度大多是过饱和的,表明冬季黄海和东海是其上方大气的源.这些数据对于估算全球碳排放具有重要作用.

In order to explore the significance of carbon monoxide(CO)emission from the ocean on the global carbon cycle,the distribution and sea-to-air flux of carbon monoxide were studied the Yellow Sea and East China Sea during winter in 2019.Atmospheric CO mixing ratios ranged from 239×10^(-9) to 941×10^(-9),with an average of(588±155)×10^(-9).The highest value of atmospheric concentration appeared in the coastal waters of the North Yellow Sea,and the lowest value appeared in the southern part of the East China Sea,showing the characteristics of high values in the Yellow Sea and low values in the East China Sea.The concentrations of CO decreased generally from coast to open sea in the atmosphere.In the surface seawater,CO concentrations were measured from 0.39 to 2.80 nmol·L^(-1),with an average of(1.23±0.45)nmol·L^(-1).The high value area appeared in the east of the East China Sea,and the low value appeared in the south of the East China Sea,which were greatly affected by solar radiation and water mass.The results of vertical distributions showed that the maximum concentration appeared in the surface layer,and the concentration decreased gradually with the increase of depth.The saturation factorαof CO ranged from 0.99 to 8.67 with an average of 2.61±1.42.As an important removal method,the sea-to-air fluxes of CO ranged from-0.05 to 41.38 nmol·m^(-2)·h^(-1) with an average of(9.80±9.70)nmol·m^(-2)·h^(-1).Compared with the atmosphere,CO in surface seawater was mostly supersaturated,indicating that the Yellow Sea and East China Sea were the sources of CO atmospheric.These data were important for estimating global carbon emissions.