台湾海峡西部海域春季表观耗氧量的垂直分布及其极小值

Vertical distribution of apparent oxygen utilization and its minimum value in western Taiwan Strait in spring

根据1984年台湾海峡西部海域综合调查资料,分析了该海区春季表观耗氧量垂直分布的特征。结果表明,AOU垂直分布趋势为上低下高。表层均呈负值(-0.16×10^(-3)～-2.55×10^(-3)),底层1/2测站呈现负值(-0.04×10^(-3)～-2.42×10^(-3));而另1/2测站呈现正值(0～0.86×10^(-3))。AOU垂直分布有极小值的站位通常出现于不同水系的交汇带,其深度在密跃层下界附近。这是由于密跃层下界附近氧的涡动扩散进行得比热的涡动传导为慢的缘故。因而,逐渐增温时,氧来不及释放到大气中,即氧呈过饱和状态。浮游植物量对极小值的形成不起决定性作用,而只能影响极小值的大小。

Based on synthetic investigation date in the western Taiwan Strait in 1984, the characters of vertical distribution of AOU in spring are analysed. The results show that vertical AOU distribution is lower on the surface layer and higher at the bottom. Its values on the surface are all negative (-0. 16 ×10^(-3)～-2. 55×10^(-3)); half of the stations also have negative values (-0. 04×10^(-3)～-2.42×10^(-3)) at the bottom layer, but the other half of station have positive values(0～0. 86×10^(-3)). The minimum value of vertical AOU distribution normally form in the mixing zone of different water systems and its depth is under the density layer, because oxygen diffusion by circular movements is slower than transportation of heat. When water temperature is increasing, oxygon is in an oversaturation state, because it has not enough time to be released into the air. Planktons are not important for the formation of minimum values though it can affect its size.