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一、引 言 自从1955年Lorenz的文章“有效势能和大气环流的维持”发表以来,大气能量循环已经成为许多大气环流研究的焦点。在这些研究中大部分使用了Lorenz介绍的有效势能 (APE)的近似形式。APE的这种近似形式包抱在等熵坐标中,对APE的二次近似和从等熵坐标向等压坐标转换中的定常静力稳定近似。Dutton和Johnson(1967年)强调等熵坐标中的能量学,因而,对APE使用了一种不包括近似的形式。 最近,Masutani和 Johnson(1986年)比较了用和不用地形、边界项以及近似形式计算的APE,其结果总结在本文的第二节中。第三节中介绍计算Montgmery流函数(s)的涡旋和纬向分解的另一种方法。 把变量S与考虑地形计算APE的确切形式(A)和等压坐标中的近似形式(θ)进行比较,在计算A和S时,没有使用计算θ时使用的近似形式。
I. INTRODUCTION Atmospheric energy circulation has become the focus of many studies of atmospheric circulation since the publication of Lorenz’s article “Effective Potential Energy and General Circulation Maintenance” in 1955. Most of these studies use the approximation of the effective potential energy (APE) introduced by Lorenz. This approximate form of APE package holds in the isentropic coordinates, a second approximation of the APE, and a steady-state approximation of the steady-state in isocentric coordinates conversion into isobaric coordinates. Dutton and Johnson (1967) emphasize the energetics in isentropic coordinates, thus using a form that does not include approximations for APEs. Recently, Masutani and Johnson (1986) compared APEs with and without topography, boundary terms, and approximations, and the results are summarized in Section II of this paper. Another method of calculating the vorticity and zonal decomposition of the Montgomery flow function (s) is described in Section III. The variable S is compared with the exact form (A) of the considered terrain calculation APE and the approximate form (?) In the isobaric coordinates, and the approximation form used in the calculation of? Is not used in the calculation of A and S.