黄、东海水母质点追踪影响因素分析

PROCESSES INFLUENCING JELLYFISH PARTICLE TRACKING IN THE YELLOW SEA AND EAST CHINA SEA

基于数值模型采用质点追踪的方法对大型水母的运移规律及其聚集的影响因素进行了研究。本文共设置6个质点释放区,分别从3、4、5月1日释放后追踪至9月30日。主要结论有:(1)采用不含潮汐过程与包含潮汐过程的水动力模式分别对表层质点进行追踪,结果表明含潮汐混合和潮汐非线性效应的POM模式对质点时空分布的模拟较为可靠;(2)基于含潮汐过程的POM模式气候态模拟结果,考虑质点垂直运动进行追踪,质点运移速度较表层追踪大大减慢,进入朝鲜/对马海峡的质点减少;其中济州岛沿岸质点几乎全部穿过朝鲜/对马海峡进入日本海,其它释放区质点最终广泛分布在南黄海以及东海中陆架,主要在黄海潮汐锋区和长江口以南沿岸锋聚集;(3)通过分析不同释放时间对质点在9月末分布的影响发现,质点释放时间偏早,即水母幼体形成较早,将使相对较多的质点向朝鲜/对马海峡聚集。

Particle-tracking based on numerical model can provide estimates to drifting pathways and help us under- stand processes that influence jellyfish gathering and blooming. We released particles in six areas on March 1, April 1 and May 1, respectively, and tracked them until September 30. The following results were obtained. （1） By comparing the tracking of surface particles based on the hydrodynamic model excluding tides and including tides, we found that the tem- poral and spatial distribution of particles simulated by POM was more reliable. （2） On the basis of POM driven by tides and climatologic forcing and the diel vertical movement, particles drifted more slowly, and less of them entered the Ko- rea/Tsushima Strait compared with the simulation without diel vertical movement. Nearly all of the particles released near the Jeju Island flowed through the Korea/Tsushima Strait and entered the Japan Sea while particles released in the other areas spread widely in the southern Yellow Sea and inner-middle shelf of the East China Sea. The simulated particles mainly aggregated near tidal fronts in the Yellow Sea and along the coastal front in the south of the Yangtze Estuary. （3） We analyzed the final positions of particles released in different months. The particles （i.e. larva medusa） released at an earlier time tended to reach the Korea/Tsushima Strait.