摘要
文中证明了不仅包括动力因子,而且包括热力因子、摩擦耗散及非绝热加热作用的和可用于三维空间的全型垂直涡度倾向方程。证明经典的、平面上的涡度方程只是它的特例。并且用该全型涡度方程严格证明了倾斜涡度发展(SVD)理论。沿着倾斜等熵面下滑的气块,当热力参数CD减小时,其垂直涡度将发展。最后通过用θ坐标模式模拟一次西南低涡的形成,证明SVD引起的涡度发展要比传统所考虑的辐合项的贡献大一个量级。
In this study,a complete form of vertical vorticity tendency equation was deduced from the Ertel potential vorticity theory.It includes not only dynamic elements,but also thermodynamic elements, frictional dissipation and diabatic heating,and is applicable to three dimensional motion.It was proved that the classical vertical vorticity equation which is appropriate only for horizontal motion is merely a special case of this newly obtained complete form equation.Based upon this equation,the theory of Slantwise Vorticity Development (SVD) proposed by Wu et al.was also proved.According to this theory,when a parrel slides down a slantwise isentropic surface and the thermal parameter C D is decreasing,its vertical vorticity develops.To verify the theory,a θ coordinate model was employed to simulate the formation of a 'southwest vortex' near the Tibetan Plateau.Results show that the vertical vorticity development due to SVD is about an order of magnitude stronger than that due to convergence which has been traditionally emphasised.
出处
《气象学报》
CSCD
北大核心
1999年第1期1-15,共15页
Acta Meteorologica Sinica
基金
国家自然科学基金重点项目
关键词
Ertel位涡
盒子定律
热力参数
涡度
倾斜涡度
Ertel potential vorticity,Box law,Circumscribed plane law,Thermal parameter C D .