摘要
根据热带地区蒸发、辐合上升运动剧烈以及海温异常的特点,构造了一个斜压模式方程组,讨论了海表温度(海温加热和海温异常变化)对热带低频波动的影响。分析表明,对天气尺度波动(Lx^Ly^106m),采用完全非地转模式,在海温异常作用下,频率明显发生变化,并容易产生波动的不稳定:海温较低时,波稳定,并随海温的增高,频率变低,波速变慢;海温较高时,会引起波动不稳定,且周期随海温的增高而变小。对超长波系统(Lx^107m,Ly^106m),可以采用半地转模式,海温作用可以激发向东传播的低频Kelvin波以及向西传播的低频Rossby波,热带超常波的波动周期随海温升高和异常增大而变长,且在海温异常作用下,波动会产生不稳定。
The important effects of SST（ SST heating and SST anomaly） on low-frequency oscillation systems in tropics are studied by baroclinic equation groups for the characteristics of strong evaporation,convergence ascending and SST anomaly in the tropics. The theoretic analyses show that non-ageostrophic model is used for precipitation cloud with smaller scale（Lx -Ly - 10^6 m）. When SST is lower,long wave is stable,and frequency and velocity are decreasing with the increase of SST; and when SST is higher, long wave is instable,and period is decreasing with the increasing of SST. For ultra-wave system（ Lx - 10^7 m, Ly - 10^6 m） , a semi-geostrophic model with SST effect is used and it can lead to eastward long Kelvin and westward long Rossby. SST heating and anomaly can lead to longer period, moreover SST anomaly can produce instable LFO （ low-frequency oscillation）.
出处
《南京气象学院学报》
CSCD
北大核心
2006年第5期688-693,共6页
Journal of Nanjing Institute of Meteorology
基金
国家自然科学基金资助项目(9021101140275011)
江苏省气象科学研究所基金项目
关键词
低频振荡
海温加热
海温异常
降水云团
超常波系统
low-frequency oscillation
SST heating
SST anomaly
precipitation cloud
ultra-long wave
