摘要
利用IAP2-LAGCM模式,做了热带西北太平洋对流层中上层两种(恒定和双周振荡)强迫热源,对北半球夏季大气低频环流影响的数值试验。结果表明,不同热源可激发出明显不同的遥相关型,与之相联系的低频系统也不同。恒定热源激发出的低频波列类似ENSO事件发生发展阶段(1972年)的PNA型,伴随的低频气旋和反气旋在热带西北太平洋生成,沿波列路径传播,在北美东南部消亡。双周振荡热源产生最显著的遥相关型位于热带西北太平洋-亚洲中纬度地区,呈经向一波型。低频系统生成于北半球,以1°·d-1的速度向北传播,在副热带地区达到最强。
In the context of the IAP 2-level AGCM, numerical study was performed of effects on summer Northern atmospheric lowfrequency circulations of two kinds of heat source forcing (constant and quasibiweekly) in the midupper troposphere. Evidence suggests that either of the sources is responsible for a particular teleconnection pattern associated with a characteristic system; the constant source excites a lowfrequency wavetrain analogous to PNA pattern associated with 1972 ENSO at a development phase and the related lowfrequency cyclone and anticyclone are produced in the tropical NW Pacific, travelling along the wavetrain and disappearing in SE North America; the quasibiweekly one generates a very strong teleconnection, showing meridional wavenumber 1 over the tropical NW Pacificmidlatitude Asia; the lowfrequency system forms in the Northern Hemisphere, moving northward at 1 degree per day and reaching its maximum strength at subtropics.
出处
《南京气象学院学报》
CSCD
1997年第4期417-424,共8页
Journal of Nanjing Institute of Meteorology
基金
国家自然科学基金
关键词
强迫热源
低频环流
气候异常
数值试验
大气环流
heat source forcing, atmospheric lowfrequency circulation, climate abnormality, lowfrequency weather system, numerical experiment