Some Statistical Properties of the Atmospheric Disturbance on 500-mb Level

[摘要] References(10)Some statistical properties of the hight disturbance of 500-mb surface at latitude circles of 20°, 30°, 40°, 50° and 60°N for the period of 11_??_20, Jan. 1949 are studied, expanding the height profile into Fourier series of 36 terms.Firstly, the daily spectral distribution of the square of the amplitude of each component wave (the spectrum of pressure) is obtained and the results are compared with “-7/3 power law” of the isotropic theory of turbulence.Secondly, the specific deviation of the daily spectrum which is the ratio of the standard deviation of the amplitude of each component to the time-mean value of it, is discussed in order to examine the criterion given by the stability theory of the baroclinic atmosphere. It is thought to be one of the outstanding features that the specific deviation is almost constant with the wave number. Thirdly, the meridional mass advection across the latitude circle is examined. There is a high negative correlation between the change in the zonal mean height deviation at 50°N and that at 30°N.Lastly, the technical problem of Fourier expansion, i.e. the estimation of numbers of terms which are necessary and enough for the expansion in the range of the accuracy of the observation and map analysis is presented.

[学科分类] 大气科学