渤海层化结构及潮汐锋面季节变化的数值研究

采用三维斜压海流模式(POM)模拟了渤海海温的季节变化,以海表与海底温差ΔT作为判别依据,发现3月份前整个渤海的表、底温差小于0.5℃,说明渤海处于充分混合状态;进入4月份以后,莱州湾、渤海中部以及渤海海峡的局部水域出现超过2℃的表、底温差,意味着垂向层化结构开始形成;层化区域面积随着海表热通量增大的趋势可一直持续到8月,9月后由于日照量逐渐减小,季节性温越层逐渐消失,11月以后渤海又恢复到充分混合的状态.

Numerical simulation of the seasonal variations of the stratification and tidal front in the Bohai Sea

A 3-D baroclinic ocean model is used to simulate the seasonal variation of temperature in Bohai Sea.Based on the difference(△T) of sea surface temperature(SST) and sea bottom temperature(SBT),it is found that △T is less than 0.5℃ throughout Bohai Sea before March,meaning that water column is mixed sufficiently; when April comes,the over 2℃ temperature difference occurs in Laizhou Bay,central basin and Bohai Sea strait,implying that the vertical stratification comes into being; the tendency that stratification area increases with heat flux through sea surface can extend to August.Thereafter,with the decreased irradiation and strengthened tidal mixing as well as wind stirring,the seasonal thermocline disappears gradually,and the water column resumes the fully mixed state.