台风“杜鹃”对西太平洋上层温度的影响研究

A study on impact of typhoon Dujuan on Western Pacific upper temperature

本文利用海气耦合模式COAWST模拟了2015年的1521号超强台风"杜鹃",并结合再分析资料综合分析了台风过境期间西太平洋上层温度的变化规律。研究结果表明台风过境会使海区内上层温度降低,最大降温可达5-6℃,降温范围直径可达上百千米,台风路径右侧温度降低幅度大于左侧,具有明显的右偏性,路径两侧降温最大差异可达4-5℃。台风过境的引起了海水的垂直混合,"冷抽吸"作用将下层温度低的海水混合到海洋上层,影响深度可达200m。海洋上层温度对台风的响应速度与深度密切相关,深度越小,响应速度越快。台风经过后造成的降温区,约在7-15d内恢复到台风经过前的温度。

In this study,the COAWST model was used to simulate the super typhoon Dujuan in 2015.Combined with the reanalysis of data,the variation of upper temperature on the Western Pacific during the transit period of typhoon was comprehensively analyzed.The results showed that the upper layer temperature on the sea area is lowered by the transit of typhoon.The maximum cooling temperature reached 5-6℃.The cooling range reached hundreds of kilometers in diameter.The temperature on the right side of the typhoon path decreased more than that on the left side,showing an obvious right deviation.The maximum difference between the two sides of the path reached 4-5℃.Typhoon transit caused a vertical mixing of seawater,and cold suction mixed low-temperature seawater in the lower layer with the upper layer of ocean,affecting a depth up to 200 m.The response speed of ocean upper temperature to typhoon was closely related to its depth.The smaller the depth,the faster the response.The cooling zone caused by typhoons passed back to the temperature before typhoon in about 7-15 days.