南海北部坡折带溶解氧分布特征及理化环境因子影响

Characteristics of dissolved oxygen and its physical and chemistry influence factors in the slope break zone in northern South China Sea

依据2010年1月南海北部坡折带冬季航次资料,发现150～1 000m层溶解氧表现出东北高、西南低的分布特征,在垂向上溶解氧整体上呈由表至底逐渐降低趋势。在强烈的水交换作用下溶解氧浓度大于8mg/dm3等值线占据50m以浅海域。中尺度暖涡在很大程度上改变了中下层海水中溶解氧空间分布,150～1 000m层暖涡中心附近海域的溶解氧含量显著高于周边未受或受暖涡影响较小的海域,此外,溶解氧与营养盐、温度、盐度、pH之间在不同层次上存在明显的相关性,表明该海域冬季溶解氧的分布受物理过程和生化过程的影响。

On the basis of the data obtained in the field survey of the northern South China Sea in January 2010, it was discovered that DO, at the depth of 150-1 000 m, decreased from northeast to southwest. Meanwhile, the vertical distribution of IX） reduced from surface to bottom. The concentration of DO contour line more than 8 mg/ dm3 occupied the 50 m shallow water influenced by strongly water exchange. It was showed that the spatial distri- bution in the middle and the bottom layer of DO changed greatly by mesoscale vortex, which lead to the concentra- tions of IX） nearby the center of warm vortex at the depth from 150 m to 500 m being remarkably higher than in other areas. Furthermore, DO shows great correlation with nutrients, temperature, salinity and pH in different layers, which indicated that the distribution of DO was influenced by physical and biochemistry process.