The Influence of Typhoon “MITAG” on Waves and Currents in Zhoushan Sea Area, China

Abstract

Typhoon “MITAG” was generated at the end of September 2019 and landed briefly in Zhoushan on October 1. Based on reanalysis data provided by ERA5 and NCEP, this paper analyzes the characteristics of wave and current during “MITAG”. The variation rule of waves and currents in different periods during the influence of “MITAG” was found. The results are as follows: The variation of significant wave height and mean wave period is related to its waveform. The single waveform has a long wave period and the correlation between wave height and wave period reaches 0.87 during the wind wave period. The wave period of the mixed waveform is shorter. The Ekman pumping of the ocean by “MITAG” is concentrated on the right side of the typhoon path when it is away from land; however, Ekman pumping is on the land side when the typhoon is close to the land. The sea surface height of the coastal sea area changes regularly with the distance of “MITAG”. The area which has a strong current is consistent with higher wave height.

Keywords

• typhoon
• “MITAG”
• wave
• currents
• Ekman
• Zhoushan