摘要
基于1949—2021年中国气象局热带气旋最佳路径数据集和登陆热带气旋数据集,对秋季登陆广东热带气旋(tropical cyclone,TCs)的时空特征和可能机制进行分析,并与夏季进行对比。结果表明:近73年共76个TCs秋季登陆广东,占登陆总数的28.5%,以强台风和超强台风占主,且平均最大强度强于夏季。相比夏季,秋TCs更大比例(72.4%)生成于西北太平洋,生成经纬度偏南、偏东;秋TCs的年均破坏潜力指标(power dissipation index,PDI)可达0.4×10^(7)m^(3)·s^(-2),与夏季相当;秋TCs登陆后比夏季更快消亡,移速更慢,PDI较小。秋TCs登陆数量长期变化呈下降趋势且下降速率与夏季相当,登陆强度上升且上升速率为夏季1.8倍,移速减缓速率为夏季2.5倍,PDI下降速率明显弱于夏季。不同于夏季登陆TCs在拉尼娜年增多,秋TCs更易在厄尔尼诺年登陆广东;登陆广东秋TCs数与上一年冬春季厄尔尼诺–南方涛动(El Niño-Southern Oscillation,ENSO)指数相关系数达到0.3,并对后一年ENSO具有指示作用。秋TCs登陆频数与太平洋年代际振荡(Pacific Decadal Oscillation,PDO)指数显著相关,1977—1996和1997—2016暖冷两个位相期,相关系数分别为−0.51和0.68。对比有无秋TCs的环境场,发现南海北部海温暖异常时,其西北侧激发的气旋性引导气流利于TCs登陆广东。
Using the track data of landed tropical cyclones(TCs)during 1949—2021 from Shanghai Typhoon Institute of China Meteorological Administration,this study analyzes the variation and mechanism of TCs landed in autumn in Guangdong area,and compares with the results in summer.The results show that a total of 76 TCs landed in Guangdong in autumn during the past 73 years,accounting for 28.5%of the landed TCs in whole year.The landed TCs in autumn(ALTCs)are mostly in categories of strong typhoon and super typhoon,and the mean peak intensities are stronger than those in summer.72.4%of the ALTCs generated in the Western North Pacific,a higher portion than summer landed TCs and the average latitude and longitude of TCs generation move southward and eastward.The yearly power dissipation index(PDI)of autumn TCs reaches 0.4×10^(7)m^(3)·s^(-2),comparable to that of summer TCs;during landfall to dissipation,the average duration time of autumn TCs is less,the translation speed is slower and PDI is less than those of summer TCs.In long-term variations,the declining trend and decrease rate of the number of ALTCs is similar to that in summer,while the landing intensity of ALTCs increases with a rate 1.8 times higher than that in summer.The translation speed of ALTCs slows down but with a rate 2.5 times lower than summer TCs,the PDI of ALTCs shows a weaker decreasing trend than summer TCs.Unlike more TCs landed in summer in La Niña year,more ALTCs appeared in El Niño years.The number of ALTCs is related to the ENSO(El Niño-Southern Oscillation)index in previous winter and spring with correlation coefficient of about 0.3.It can be used as an indicator for next-year ENSO prediction.In decadal variability,the correlation coefficients between the number of ALTCs and the PDO(Pacific Decadal Oscillation)index,were−0.51 and 0.68 in the warm phase(1977—1996)and cold phase(1997—2016),respectively.The composite analysis shows that ALTCs can occur with a warm sea surface temperature anomaly in the northern South China Sea,which induced cyclonic atmospheric circulation in the South China and favors TCs landed in Guangdong.
作者
韩鼎妍
李敏
胡睿
谢玲玲
HAN Dingyan;LI Min;HU Rui;XIE Lingling(Laboratory of Coastal Variation and Disaster Prediction,College of Ocean and Meteorology,Guangdong Ocean University,Zhanjiang 524088,China;Key Laboratory of Climate,Resources and Environment in Continental Shelf Sea and Deep Ocean of Department of Education of Guangdong Province,Zhanjiang 524088,China;Key Laboratory of Space Ocean Remote Sensing and Applications(LORA),Ministry of Natural Resources,Zhanjiang 524088,China)
出处
《热带海洋学报》
CAS
CSCD
北大核心
2024年第1期64-78,共15页
Journal of Tropical Oceanography
基金
国家自然科学基金(42276019)
广东省粤西热带海洋生态环境野外观测研究站项目。
关键词
秋季登陆热带气旋
变化趋势
年际变化
ENSO
landed tropical cyclone in autumn
long-term variation
interannual variability
ENSO
