大连湾表层海水CO_2、CH_4和N_2O的分布及海-气交换通量

Distribution and atmospheric fluxes of CO_2,CH_4 and N_2O in surface water of Dalian Bay

根据2009和2010年两个航次对大连湾进行的大面调查,测定了不同季节表层海水中CO2分压、CH4和N2O的水平分布。结果表明,大连湾表层海水pCO2的季节变化不大,秋冬两季表层海水pCO2范围分别为44.00-51.55 Pa和35.45-56.21 Pa,统计平均值分别为47.77 Pa和40.05 Pa;大连湾表层海水中溶解CH4浓度的季节变化不大,但其饱和度差异明显,秋季远高于冬季;海水中溶解N2O饱和度的季节变化不大,浓度变化较显著,冬季远高于秋季。利用Liss和Merlivat公式和Wanninkhof公式分别估算了大连湾秋冬2个季节三者的海-气交换通量,结果表明秋季大连湾为大气CO2、CH4和N2O的源区,而冬季大连湾主要为大气CO2的汇区,是大气CH4和N2O的源区。

The partial pressure of CO2（pCO2）,methane（CH4） and Nitrous oxide（N2O） were measured in the surface water of Dalian Bay during 2 surveys from 2009 to 2010.The results showed that pCO2 ranged from 44.00 to 51.55 Pa in autumn,with an average of 47.77 Pa.While in the winter it ranged from 35.45 to 56.21 Pa,with an average of 40.05 Pa.There were not the obvious seasonal variations for the concentrations of dissolved CH4 in the surface waters of Dalian Bay.While there were the seasonal variations for CH4 saturations.Its saturations were higher in autumn than winter.The seasonal variations of N2O saturation in the water were not obvious,but the variations of concentrations were serious,and were higher in winter than autumn.The sea-air exchange fluxes of CO2,CH4 and N2O was estimated using the Liss and Merlivat and Wanninkhof formula.The result showed that it was net sources from the atmospheric CH4 and N2O in autumn and winter.While it was net sources of the atmospheric CO2 in autumn,but the sink in winter.