胶州湾表层海水NO的分布特征及其影响因素

为了解近海海水中NO的时空分布特征及其影响因素,采用化学发光法对2010—2011年胶州湾内表层海水中的c(NO)进行了观测,并结合水文、生物等要素的同步观测资料,探讨了该海域NO分布特征及影响因素.结果表明:胶州湾内表层海水c(NO)春季最低,为(11.8±4.6) pmol/L；秋季最高,为(471.3±106.3) pmol/L；夏季和冬季差别不大.该海域c(NO)的水平分JP+1]布呈湾中心及湾口部分较低、河口较高的特点.湾口部分c(NO)春季最低,为2.0 pmol/L；湾中心部分c(NO)秋季最高,达356.0 pmol/L.c(NO)与温度、盐度及c(NO₂-)表现出相关性,陆地径流输入对海水中NO的分布也有影响,大沽河下游丰水季c(NO)达到348.1 pmol/L,枯水季c(NO)仅为119.8 pmol/L.研究显示,胶州湾表层海水为大气NO的源,2010—2011年胶州湾表层海水NO的海-气通量为3.8×10-15 mol/(cm2·s),胶州湾年NO释放量(以N计)约为5.8×106 g. 

Distribution and Influencing Factors of Nitric Oxide in the Surface Water of Jiaozhou Bay

Abstract:To understand the characteristics of spatiotemporal distribution of nitric oxide(NO) and its control factors along coastal areas, the concentration of NO(c(NO)) in the surface water of Jiaozhou Bay was analyzed by using the chemiluminescence method. Combining hydrological and biological parameters obtained at the same time, c(NO), distribution characteristics and control factors were investigated in the area. The results showed that c(NO) reached the maximum in autumn and the minimum in spring, with the average values of(471.3±106.3) pmol/L and(11.8±4.6) pmol/L, respectively. The difference of c(NO) between summer and winter was insignificant. Low c(NO) was detected at the mouth and the center of Jiaozhou Bay. In spring, the c(NO) was 2.0 pmol/L at the mouth, lowest among the four seasons. In autumn, the c(NO) was highest among the four seasons, up to 356.0 pmol/L in the central region of the bay. c(NO) had relationships with temperature, salinity and the concentration of NO₂-. The terrestrial runoff also affected c(NO). In the Dagu River, c(NO) was 348.1 pmol/L and 119.8 pmol/L in the wet and dry season, respectively. The present study showed that Jiaozhou Bay was a source of atmospheric NO during 2010-2011. The air-sea flux of NO in the surface seawater of the bay was about 3.76×10-15 mol/(cm2·s), and its annual emission was about 5.8×106 g.