2021年西北太平洋热带气旋生成数量的春季海温预报因子的特征分析

Characteristic Analysis of Spring Sea Surface Temperature Predictors for the Number of Western North Pacific Tropical Cyclones in 2021

在西北太平洋(WNP)海域生成的热带气旋(TC)可能会对沿海地区的农业生产造成严重的自然灾害,对WNP海域TC生成数量的气候预测可以为台风灾害的防灾减灾提供有益的信息。以往的研究指出春季(3—5月)的热带大洋海表面温度(SST)异常(西南太平洋与西北太平洋暖池之间的SST梯度和热带北大西洋SST)可以作为预报因子,预测台风盛期(6—10月)WNP海域生成的TC总数量。本文分析了2021年这两种春季海温预报因子的异常特征,结果表明:2021年春季西南太平洋与西北太平洋暖池之间的SST梯度呈现负异常(-0.33℃),同时热带北大西洋SST也呈现负异常(-0.12℃),这两种春季海温预报因子的负异常可能会引起WNP海域出现TC生成数量偏多的情况。

Tropical cyclones(TCs)formed over the western North Pacific(WNP)may cause serious natural disasters to agricultural production in coastal areas.The climate prediction of the TC number formed over the WNP could provide useful information for the prevention and mitigation of typhoon disasters.Previous studies have revealed that the tropical sea surface temperature(SST)anomalies(the SST gradient between the southwest Pacific and northwest Pacific warm pool and the tropical North Atlantic SST)in spring(March-May)can be used as predictors,to predict the total TC number over the WNP during the following typhoon peak season(June-October).This paper analyzes the anomalous characteristics of the two SST predictors in the spring of 2021.The results show that the SST gradient between the southwest Pacific and northwest Pacific warm pool in the spring of 2021 had a negative anomaly(-0.33℃),and the tropical North Atlantic SST also showed a negative anomaly(-0.12℃).The negative anomalies of these two spring SST predictors may possibly be beneficial to the increase in the TC number over the WNP in 2021.