胶州湾及邻近海域表层海水中一氧化氮浓度分布及其影响因素探讨

Distribution and Controlling Factors of Nitric Oxide Concentrations in Surface Seawater of Jiaozhou Bay and Adjacent Waters

2011年2～3月利用化学发光法对胶州湾及邻近海域表层海水中一氧化氮(NO)浓度进行了监测.结合水文、化学和生物等要素的同步观测资料,对该海域NO浓度分布及其影响因素进行了探讨.结果表明,胶州湾内表层海水中NO浓度为0.080～0.493 nmol.L-1,平均值为(0.292±0.146)nmol.L-1,胶州湾外NO浓度为未检出～0.435 nmol.L-1,平均值为(0.160±0.130)nmol.L-1.总体来说,胶州湾表层海水中NO浓度呈现出自湾内向湾外递降的分布趋势,陆地径流和人为活动可能对NO浓度的分布造成一定程度的影响.胶州湾及邻近海域表层海水中NO浓度比开阔大洋高1个数量级.周日变化研究表明,NO浓度具有一定的变化特征,最大值出现在15:00,这可能主要受光照的影响.影响NO浓度分布的因素比较复杂,可能主要受亚硝酸盐、光强和pH等因素的影响.结果表明,2011年春季胶州湾及邻近海域表层海水是大气NO的源,通量约为1.09×10-15 mol.(cm2.s)-1.

Distribution of nitric oxide（NO） concentrations in surface seawater of Jiaozhou Bay and adjacent waters was studied adopting the chemiluminescence method during February and March 2011.Based on the data of NO concentrations and related environmental parameters in hydrology,chemistry and biology,the distribution and controlling factors were discussed.The results showed that the range and the mean of NO concentrations in surface seawater of Jiaozhou Bay were 0.080-0.493 nmol·L-1 and（0.292±0.146） nmol·L-1,respectively.The concentrations of NO ranged from below detection limit to 0.435 nmol·L-1 in adjacent waters of Jiaozhou Bay,with the mean of（0.160±0.130） nmol·L-1.The concentrations of NO showed a gradually decreasing trend from inside to outside of Jiaozhou Bay,which was possibly due to the effect of terrestrial runoff and human activities.The NO concentration of surface seawater in Jiaozhou Bay and adjacent waters was one order of magnitude higher than that in the open sea.The concentrations of NO in the surface seawater exhibited an obvious diurnal variation.The highest concentration of NO appeared at 15：00,which was presumably due to the effect of illumination intensity.The influencing factors of NO concentration and distribution were complex,including nitrite,pH,light intensity and so on.The present study showed that Jiaozhou Bay and adjacent waters was a source of atmosphere NO in spring,and FNO was about 1.09×10-15 mol·（cm2·s）-1.