利用FY-4A卫星资料研究海洋热含量对台风强度的影响

Investigation of effects of ocean heat content on typhoon intensity using FY-4A satellite data

随着全球气候不断变化,平均海面温度持续升高,我国东南沿海至西北太平洋周边台风频繁发生,海温与台风发生及发展的关系问题成为现阶段气候变化区域响应研究的热点。本文利用FY-4A融合海温数据、NOAA气候态数据WOA18和CMEMS海面高度异常数据,采用海洋热含量(TCHP)算法计算获得2019年西北太平洋海洋热含量空间分布数据,并根据两层约化重力模式和海水状态方程计算出的H_(26)(从海面到26°C等温线深度)与Argo数据进行验证分析,用来检验研究方法的可行性。最后结合我国东南沿海及西北太平洋2019年台风数据,将TCHP和H_(26)与台风强度进行拟合。结果表明:TCHP和H_(26)与台风强度四次多项式的拟合效果较好,拟合RMSE分别为19.1和28.2。根据海-气交换原理,研究结果表明台风所经过海面的海洋热量影响着台风的变化趋势,海洋热含量越高,台风后期发展的强度越大,台风等级也就越高。

With the global climate change,the average sea surface temperature(SST) continues to rise,typhoons occur frequently from the southeast coast of China to the northwest Pacific.Therefore,the relationship between SST and the occurrence and development of typhoons has become a hot topic in regional response to climate change.In order to further study the relationship between OHC and typhoon intensity variation,this study used FY-4A to integrate SST data,NOAA climate state data WOA18 and CMEMS sea surface height anomaly data,as well as the tropical Cyclone Heat Potential(TCHP) algorithm to calculate the spatial distribution data of tropical cyclone heat potential in the northwest Pacific in 2019.The H_(26)(isotherm depth from sea surface to 26 °C) calculated by the two-layer of reduced gravity pattern and the equation of state of seawater were compared with Argo data to verify the feasibility of the research method.Finally,TCHP and H_(26)were fitted with typhoon intensity based on the typhoon data of the southeast coast of China and the northwest Pacific in 2019.The results show that TCHP and H_(26)have a good fitting effect with the quardic polynomial of typhoon intensity,and the fitting Root Mean Square Error(RMSE) is 19.126 and 28.264,respectively.According to the air-sea exchange principle,the research results show that the ocean heat over the sea surface of typhoon affects the change trend of typhoon.The higher the ocean heat content is,the greater the intensity of typhoon,and the higher the typhoon grade would be.