基于HYCOM再分析数据的浙江近海对台风“灿鸿”(2015)的响应研究

THE RESPONSE TO TYPHOON CHAN-HOM(2015)OFF ZHEJIANG BASED ON HYCOM RESULT

基于混合坐标海洋模型(HYbrid coordinate ocean model,HYCOM)再分析数据研究浙江近海对2015年第9号台风“灿鸿”的动力学和热力学响应,并利用卫星遥感的海表面温度(sea surface temperature,SST)数据验证了HYCOM再分析数据的合理性。结果显示,“灿鸿”在浙江近海引起了较强的近惯性运动,最大流速约为0.4 m/s。台风“灿鸿”引起的近惯性能量在300 m以深海域较强,其衰减的e折时间尺度约为4-12 d。“灿鸿”所引起的SST变化约-3--1℃,降温过程持续约7 d;同时在近岸海底引起了增温,最大温度变化幅度为10℃左右,持续时间也约为7 d(浙江近岸)。经过分析,本文认为近岸海底的增温是由台风引起的次级环流和台风引起的强混合共同导致的。

Based on the HYCOM reanalysis data,dynamical and thermodynamical responses to typhoon Chan-hom(2015)off Zhejiang,China was studied.The sea surface temperature(SST)data from remote sensing systems were used to validate the HYCOM reanalysis data.Results show that Chan-hom caused strong near-inertial waves in Zhejiang offshore with the maximum velocity of 0.4 m/s.The near-inertial energy caused by Chan-hom was stronger in the regions of depth>300 m.The e-folding time of the near-inertial energy was 4-12 days.Chan-Hom also caused significant surface temperature cooling(-3--1℃)and bottom temperature heating(maximum 10℃),which lasted for approximate 7 days.Through analysis,we speculated that the bottom temperature heating was caused by the secondary circulation and mixing induced by typhoon Chan-Hom.