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A numerical experiment for the study of the development of tropical cyclones is performed with a 10-level axisymmetric model. In this model, the wind in the boundary layer is computed directly from the primitive equation of motion, but gradient balance is assumed above the boundary layer. The contribution of deep cumulus clouds to the heating of the large scale environment is parameterized along the lines of Kuo (1965) and Sundqvist (1970). The effect of the upward transport of momentum by cumulus clouds is also included in a crude manner. The experiment shows that the present model is capable of describing many features observed in real tropical cyclones. Our result differs from Sundqvist (1970) in one major aspect, namely, no rapid decay occurs after the mature stage if the external conditions and parameters remain unchanged, which is in agreement with the result of Ooyama (1969). The development process and the structure of the simulated tropical cyclone are discussed in some detail. DOI: 10.1111/j.2153-3490.1975.tb01667.x

By means of highly truncated spherical harmonic expansions, an extended four-level quasi-geostrophic model with variable Coriolis parameter is transformed into a set of ordinary non-linear differential equations. Non-adiabatic effects, frictional dissipation, and boundary effects are approximately included in the equations. A numerical experiment made with the equations succeeds in producing many realistic statistical gross features, especially in the lower stratosphere, e. g., a poleward temperature incrase, the up-gradient horizontal transports of heat and momentum due to large-scale eddies, the upward energy flux of extra-long waves, and the trapping of the upward energy flux of tropospheric unstable waves near the tropopause. The mean energy flow in the lower stratosphere and in the troposphere are analyzed and compared with each other, indicating very clearly the baroclinical activness of the troposphere and the passiveness of the lower stratosphere. The dynamics in the lower stratosphere are discussed. the mean meridional circulation is also studied.

The existence of the phenomenon that the temperature in certain layers of the earth's atmosphere is higher at the pole than at the equator is considered as a general problem in planetary fluid dynamics. In a highly simplified model the solution of the problem depends upon a group of non-dimensional parameters. Taking the parameters of the earth's atmosphere as an example, numerical experiments were performed to study the nature of such a meridional counterradiational-heating temperature gradient and the dependence of it on the vertical variation of meridional differential radiation. Some general inferences were drawn from the experiments.

tance. This counter may also be used for monitoring relatively flat surfaces such as laboratory tables for lowenergy beta particles. The plateau has less than a 4% rise per hundred volts from 1350 to 1550 volts. In this laboratory, the background of the counter shielded with 2 in. of lead is 28 cpm at 1375 volts. A 10-mg sample of barium carbonate containing 0.0005 [tc of C14 spread on a 10-cm2 surface, gave a counting rate of 564 epm (uncorrected) at 1375 volts. The sensitive area available on the sample holder is 20 cm2. The counting gas is inexpensive and readily available. The counter is simple to construct or may be obtained commercially.2 The time required for replacing

Wang [1–7] demonstrated that the midbrain reticular formation has a facilitatory effect and that the reticular formation of the medulla has an inhibitory effect, respectively, on the galvanic skin reflex (GSR), and he concluded that the specific locations in the reticular formation that facilitate or inhibit the galvanic skin reflex were perhaps not identical with the centers found by Magoun et al. to be related to facilitation and inhibition of somatic reflexes. In the present work, the effect on galvanic skin activity of electrical stimuli applied systematically to the brainstem reticular formation, point-by-point with the aid of a stereotaxic apparatus, is examined.

The influence of transverse magnetic field on surface a.c. field-effect in germanium has been studied, and a different interpretation from other inverstigators is proposed. According to our experimental results, it may be considered that the influence of magnetic field on surface field-effect is predominantly referred to the additional change in conductance of sample caused by the "magnetic-concentration effect" rather than the change in surface barrier height caused by the Hall e.m.f., and we also suggest the possibility of using this experiment to determine the dependence of the surface recombination velocity on the surface barrier.