双台风及其对海洋环境影响的遥感分析

摘要

The temporal-spatial characteristics and variations of double-typhoon Bolaven and Tembin happened in August 2012 were analyzed by using sea surface temperature (SST),chlorophyll concentration,wind speed and precipitation retrieved from multi-satellite data sets,and the main factors affecting the changes were also discussed.Ekman pumping was estimated from wind speed and direction data measured by Windsat.Windsat’s data can clearly show that the double-typhoon have caused the emergence of a strong upwelling.Due to the effect of Ekman pumping,cold water goes up to the sea surface hybrid layer, and makes sea surface temperature decreased.The sea surface temperature data provided by the microwave radiometer shows the maximum decrease of SST up to 5.5℃,and the reduced region is same as the region with strong Ekman pumping;Typhoon area has strong precipitation and a wide range of rainfall occurred due to the impact of double-typhoon (up to the maximum of 15.4mm/h).Chlorophyll concentration has been significantly increased,but it was delayed for some days.Compared with single typhoon,double-typhoon causes much stronger ocean-atmosphere interaction.%本文利用多源卫星观测资料，分析了2012年8月双台风“布拉万”、“天秤”过境前后的 Ekman 抽吸、海表温度、叶绿素浓度及降水的时空变化特征，并探讨了影响其变化的主要因子。利用 WindSat 风场资料可以观测到双台风引起的强烈上升流使得下层冷水进入海表上混合层，从而使海表温度 SST 有所降低，对微波辐射计观测到的海表温度数据进行分析，SST 最大降温达5．5℃，且 SST 降温区域与 Ekman 抽吸最强区域基本吻合；降雨强度空间分布与风场图所示台风路径一致，其最大降雨速率可达15．4mm/h，并且双台风产生的雨带不同于单台风的大范围降雨，海洋表层叶绿素 a 浓度在台风过后几天也有了明显的升高，这说明双台风较单台风能引起更强的海洋大气相互作用。