夏季西北太平洋热带气旋生成频次与热带海温关系的年代际变化  

INTERDECADAL CHANGE IN THE RELATIONSHIP BETWEEN SUMMER TROPICAL CYCLONE GENESIS FREQUENCY OVER THE WESTERN NORTH PACIFIC AND TROPICAL SEA SURFACE TEMPERATURE

作　　者：陈慕妍 陈锐丹 CHEN Muyan;CHEN Ruidan(School of Atmospheric Sciences,Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,China;Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies,Sun Yat-sen University,Zhuhai 519082,China)

机构地区：[1]中山大学大气科学学院/南方海洋科学与工程广东省实验室(珠海),广东珠海519082 [2]广东省气候变化与自然灾害研究重点实验室,广东珠海519082

出　　处：《热带气象学报》2022年第1期58-67,共10页Journal of Tropical Meteorology

基　　金：国家重点研发计划(2016YFA0600601);广东省基础与应用基础研究基金(2020A1515011572);广东省气候变化与自然灾害研究重点实验室(2020B1212060025)共同资助。

摘　　要：探讨了夏季(6-8月)西北太平洋(Western North Pacific,WNP)热带气旋生成频次(Tropical Cyclone Genesis Frequency,TCGF)与热带海温关系的年代际变化,发现影响WNP TCGF的热带海温型在1991/1992年发生了年代际变化。在1990年代初之前,TCGF正异常对应的热带海温异常(Sea Surface Temperature Anomaly,SSTA)呈现东部型La Niña衰减位相,前冬至春季WNP局地暖SSTA在其西北侧激发气旋异常,夏季时由热带印度洋冷SSTA继续维持。在1990年代初之后,TCGF正异常对应的热带SSTA呈现东部型La Niña向中部型El Niño快速转换的位相,夏季中太平洋暖SSTA在其西北侧激发气旋异常,同时热带东印度洋至海洋性大陆以及热带大西洋的冷SSTA通过垂直环流圈加强中太平洋的辐合上升运动,进一步维持其西北侧气旋异常。由于激发气旋异常的暖SSTA在第二个年代相较第一个年代明显偏南偏东,气旋异常和TCGF正异常在第二个年代也整体偏南且向东扩展至更远的区域。WNP TCGF与热带海温关系的年代际变化与1990年代初之后厄尔尼诺-南方涛动演变速率加快有关。The interdecadal change in the relationship between summer(June—August)tropical cyclone genesis frequency(TCGF)over the western North Pacific(WNP)and tropical sea surface temperature anomaly(SSTA)is investigated in this paper.Results show that the tropical SSTA pattern affecting the WNP TCGF has experienced an interdecadal change in 1991/92.Before the early 1990s,the positive TCGF anomaly corresponds to the eastern Pacific La Ni?a decaying phase.From the preceding winter to spring,the WNP local warming triggers an anomalous cyclone to its northwest,which is maintained by the cold SSTA over the tropical Indian Ocean in summer.After the early 1990s,the positive TCGF anomaly is related to the transition phase from eastern Pacific La Ni?a to central Pacific El Ni?o.In summer,an anomalous cyclone is induced by the warm SSTA over the central Pacific to its northwest and further intensified by the cold SSTA over the tropical eastern Indian Ocean,Maritime Continent and the tropical Atlantic,which could strengthen the convergent and upward motions over the central Pacific through vertical circulations.Since the warm SSTA is located further southward and eastward in the later period,the cyclonic anomaly and positive TCGF anomaly are both located more southward and extend further eastward in the later period.The interdecadal change in the relationship between the WNP TCGF and tropical SSTA is related to the accelerated evolution of El Ni?o-Southern Oscillation after the early 1990s.

关 键 词：热带气旋 生成频次 热带海温 年际 年代际变化 

分 类 号：P732[天文地球—海洋科学]