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Dynamic study is undertaken of the tropical atmospheric CISK–Rossby wave genesis and propagation mechanisms, the vertical
structure of the low–frequency wave and the basic characteristics and constraint of the vertical transport of momentum and
wave energy fluxes in relation to the quasi–biennial oscillation (QBO) of the stratospheric zonal winds over the tropics in
the context of a baroclinic quasi–geostrophic model. Results suggest that in the properly posed thermal conditions and zonal
belt there exist two kinds of CISK–Rossby waves of low frequency (LF) and very low frequency (VLF), travelling zonally in
opposite directions, which act as sources responsible for upward transferring momentum and wave energy fluxes for easterly
and westerly perturbations in such a way as to provide required momentum and energy for the stratospheric QBO genesis and maintenance. The present study offers interpretations for some of the fundamental observational facts of the
QBO and proposes new ideas of the QBO generation mechanism.
This work was supported jointly by the National Natural Sciences Foundation of China (No.49975012) and by the Program of Basic
Theoretical Research of the PLA Headquarters of General Staff. 相似文献
2.
运用一个包含Wave-CISK机制的斜压半地转8层模式和本征函数展开方法,研究了三种不同的对流凝结加热廓线对低纬大气的30—60天低频振荡的影响。研究表明,不同的加热廓线分布时30~60天低频振荡具有不同的相速和周期,并且低频振荡特征相速的量级都是o(10m/s),由Wave-CISK机制激发的低频CISK—Kelvin波和CISK—Rossby波都是稳定的。同时,还进一步揭示了不同加热廓线对低纬大气30~60天低频振荡垂直结构的影响。 相似文献
3.
To add to the growing mature research on the tropical 30-50 day oscillations from a new prospective,
the current work bases on dynamic analysis of baroclinic quasi-geostrophic models to discuss dynamic
mechanisms for the generation and propagation of CISK-Rossby waves, and to understand restraints and effects
of different wave structures and thermodynamic forcing on the 30-50 day oscillations in the tropical atmosphere.
Some important properties of the oscillation propagation have been explained and, in detail, with respect to its
meridional propagation and vertical “baroclinic” structure. The work has come up with some new opinions and
viewpoints. New opinions about the propagation and energy dispersion are to be proved by more observations
and study. 相似文献
4.
Jiang Guorong 《大气科学进展》1996,13(1):115-123
In terms of a baroclinic quasi-geostrophic wave-filtering technique in connection with a dimensionless paramet-er, η(z), of condensation-released latent heat that indicates the CISK mechanism, a model is established for des-cribing tropical atmosphere CISK-Rossby waves alongside its analytical solution. Theoretical study shows that there exists pronounced difference between Rossby waves, CISK-involving and classic, and the former can be used to in-terpret some aspects of the low-frequency oscillation in the tropical atmosphere 相似文献
5.
热带大气的CISK-Rossby波和30-50天振荡 总被引:1,自引:0,他引:1
利用斜压准地转滤波方法,通过引入一个反映CISK机制的无量纲凝结潜热参数η(Z),建立了描述热带大气的CISK-Rossby波模式,并求得了该模式的解析解。理论研究表明,考虑CISK机制的CISK-Rossby波与经典的Rossby波有明显差别,它可较好地解释热带大气30-50d振荡现象。 相似文献
6.
CISK-rossby wave and the 30-60 Day Oscillation in the Tropics 总被引:1,自引:0,他引:1
The 30-60 day oscillation is an important aspect of the atmospheric variance in the tropical area. A number of works have been done on this phenomenon, this article is a further one. A quasi-geostrophic linear model that consists of a two-layer free atmosphere and a well-mixed boundary layer is used to investigate the instability of intraseasonal oscillation, its propagation and vertical structures. Results show that the dynamical coupling and interaction between the barotropic and baroclinic components via boundary layer convergence / divergence are responsible for the appearance of a new kind of low-frequency wave. Such wave is very different from the traditional tropical Rossby wave. It can propagate westward and eastward. Some behaviours of it appear to resemble the observed 30-60 day oscillation mode in many aspects, such,as vertical structures, zonal and meridional propagations. Now many researchers emphasize the direct relationship between CISK-Kelvin mode and the tropical atmospheric 30-60 oscil 相似文献
7.
1.IntroductionThelow~frequencyoscillation(LFO)isaveryimPOrtantweatherphenomenonintheatmosphere.The30--50--dayandquasichiweeklyoscillationsinthetropicalatmospherearemostintensivelystudied,andcomParativelyspeaking,anotherkindofLFOconcernillgtheQBOofthestratosphericzonalwindsismuchlessstudied,which,althoughoccurringinthestratosphere,bearsacloserelationtothetroposphericactivitiesandtheevolutionoflow--latitudecirculationssothatitisworthwhiletoexploreindepththephysicalmechanismfortheQBOoccurre… 相似文献
8.
The 30–60 day oscillation is an important aspect of the atmospheric variance in the tropical area. A number of works have
been done on this phenomenon, this article is a further one. A quasi-geostrophic linear model that consists of a two-layer
free atmosphere and a well-mixed boundary layer is used to investigate the instability of intraseasonal oscillation, its propagation
and vertical structures. Results show that the dynamical coupling and interaction between the barotropic and baroclinic components
via boundary layer convergence / divergence are responsible for the appearance of a new kind of low-frequency wave. Such wave
is very different from the traditional tropical Rossby wave. It can propagate westward and eastward. Some behaviours of it
appear to resemble the observed 30–60 day oscillation mode in many aspects, such.as vertical structures, zonal and meridional
propagations. Now many researchers emphasize the direct relationship between CISK-Kelvin mode and the tropical atmospheric
30–60 oscillation. It is considered that CISK-Rossby mode should not be neglected. 相似文献
9.
Wave-CISK和低纬大气低频振荡 总被引:2,自引:0,他引:2
本文运用一个包含Wave-CISK机制的斜压半地转模式来讨论低纬大气中的低频振荡。在我们以前研究工作的基础上,不仅考虑了CISK机制的作用,而且考虑了CISK机制垂直速度w[B]随纬度的变化。这样,建立的半地转模式和相应的解析解更能反映CISK机制对低纬低频振荡的作用。在求解中,我们运用了本征函数S[-3/2][m](Sonine多项式)展开的方法,结果不仅得到了模式中所含的CISK-Kelvin波和CISK-Rossby波波速与对流凝结潜热参数η的关系,而且显示了低纬高、低层大气间的相互耦合作用。在这样 相似文献
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