###
气象:2023,49(12):1468-1480
本文二维码信息
码上扫一扫!
2021年南海夏季风爆发偏迟原因分析
郑彬,谷德军,林爱兰,陈静,屈静玄,朱泳
(中国气象局广州热带海洋气象研究所/广东省区域数值天气预报重点实验室,广州 510640)
Possible Causes for Late Onset of the South China Sea Summer Monsoon in 2021
ZHENG Bin,GU Dejun,LIN Ailan,CHEN Jing,QU Jingxuan,ZHU Yong
(Guangzhou Institute of Tropical and Marine Meteorology, CMA/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, Guangzhou 510640)
摘要
图/表
参考文献
相似文献
本文已被:浏览 96次   下载 624
投稿时间:2022-01-11    修订日期:2023-10-17
中文摘要: 通常La Nina年南海夏季风爆发偏早,但是2021年La Nina背景下南海夏季风于5月第6候爆发,较常年偏迟。利用NCEP/NCAR再分析资料,从热带海温异常(SSTA)和季节内振荡(ISO)北传的角度来分析2021年南海夏季风爆发偏迟的原因。结果表明La Nina确实使春季的西太平洋副热带高压(以下简称西太副高)减弱,特别是4月之前;但是由于热带印度洋海温在冬春季持续偏暖的背景下抵消了La Nina的影响,特别是在5月,La Nina的影响小于热带印度洋的作用,导致5月西太副高偏强,南海夏季风爆发偏迟。此外,受La Nina影响,4月西太副高偏弱,南海地区背景正压南风偏弱,〖JP2〗不利于南海地区赤道ISO的北传,这与气候态正好相反;随着热带印度洋SSTA的影响越来越显著,西太副高逐渐加强,直到5月下旬,背景正压经向南风才扩展到10°N以南地区,导致2021年南海地区赤道ISO北传偏迟,这也是2021年南海夏季风爆发偏迟的一个重要原因。热带印度洋和太平洋SSTA通过“竞争”共同对南海夏季风爆发产生影响,因此关注二者在冬春季的发展非常重要。
Abstract:The South China Sea summer monsoon usually breaks out earlier in the La Nina year, but a late onset (6th pentad of May) appeared in 2021, though 2020/2021 was the year of La Nina. Using NCEP/NCAR reanalysis data, the reasons for the late onset of the South China Sea summer monsoon in 2021 are analyzed from the perspective of tropical sea surface temperature anomaly (SSTA) and intraseasonal oscillation (ISO) northward propagation. The results show that La Nina did weaken the Western Pacific subtropical high in spring, especially before April. However, the tropical Indian Ocean sea surface temperature in the winter and spring continued to be warmer, offsetting the impact of La Nina, especially in May. The influence of La Nina was less than that of the tropical Indian Ocean, resulting in the stronger Western Pacific subtropical high in May and the late onset of the South China Sea summer monsoon. In addition, due to the influence of La Nina, the Western Pacific subtropical high in April was weak and the background barotropic southerly in the South China Sea was weak, which unfavored the equatorial ISO in the South China Sea propagating northward. As the influence of tropical Indian Ocean SSTA became more and more significant, the Western Pacific subtropical high has gradually strengthened, and the background barotropic southerly did not extend to the area south of 10°N until late May, casusing a late northward propagation of the equatorial ISO in the South China Sea in 2021, which is the opposite of the climatic state. This is also an important reason for the late onset of the South China Sea summer monsoon in 2021. The tropical Indian Ocean and Pacific SSTAs together have an impact on the onset of the South China Sea summer monsoon through competition, so it is very important to pay attention to the development of the two in winter and spring.
文章编号:     中图分类号:    文献标志码:
基金项目:广东省基础与应用基础研究基金项目(2021A1515011399、2022A1515011870)和国家自然科学基金项目(41705089)共同资助
引用文本:
郑彬,谷德军,林爱兰,陈静,屈静玄,朱泳,2023.2021年南海夏季风爆发偏迟原因分析[J].气象,49(12):1468-1480.
ZHENG Bin,GU Dejun,LIN Ailan,CHEN Jing,QU Jingxuan,ZHU Yong,2023.Possible Causes for Late Onset of the South China Sea Summer Monsoon in 2021[J].Meteor Mon,49(12):1468-1480.