On the Periodic Fluctuation of Air Temperature (1)

[摘要] The author tried to analyse the quasi-periodic change of air temperature.The duration and amplitude of the individual fluctuations are nearly determinate, yet subject to some small variation with time.The following method can be applied to other natural phenomena. Suppose yn denotes air temperature or other natural phenomena as a function of time expressed by the following expression: where n is an integer, τ a certain time interval, θ time epoch, and T the period which varies with n.Now we define L and S as follows: accordingly, From (1) and (2) we get If T(nτ)=2τ, Therefore by choosing τ properly, we can anapyse yn into two parts, i. e. periodic and nonleriodic terms.Applying the above method, the author has found five systematic terms in the change of the monthly mean temperature over Japan proper and its vicinity, two of which seem to reign over the whole northern hemisphere. Some considerations are made on their physical meaning.

[学科分类] 大气科学