The interest for spectral forms of the meteorological equations has grown considerably over the past several years. Integrations in terms of spherical harmonics provide us with an interesting alternative to the grid point method. The results of an extension of the method to the complete meteorological equations will be presented here. A model based on five levels and 15 coefficients is integrated for 200 days starting from an atmosphere at rest and at a uniform temperature. The integration is then continued for another 22 days with 45 coefficients. Cross-sections show a jet stream in each hemisphere and low level easterlies along the equatorial belt. The amplitudes and the phase speeds of the planetary waves in the model compare favourably with their atmospheric equivalents. The results of this integration indicate that spherical harmonics could be used profitably in general circulation models or in the preparation of extended range forecasts.
Relationship between solar activity and precipitation was studied by means of key day analysis. Daily amounts of precipitation are averaged at several stations in the Far East during the period of intense solar flare and strong and weak geomagnetic disturbance. Distinct increase of precipitation is found on days with intense solar flare. This suggests that soft X ray or very fast particle flow (probably cosmic rays emmitted from solar flare) stimulates the precipitation. Increases of precipitation are also found at some stations on days with strong geomagnetic disturbance or 6 days later. This may be due to secondary circulations which are stimulated by the initial responses.
Anomalies of atmospheric ice nuclei of short duration were observed under thunderclouds. The result of analysis of meteorological condition shows that the anomalies were associated with downdrafts in and under the thunderclouds.
Simultaneous observation of surface electric field, charge on snow particles, rate of snowfall, crystal type of snow crystals was made during snowfall in four winter seasons from 1956 to 1960 in Sapporo. Various patterns of the surface electric field occurred during the observation. From the observational results obtained, the following conclusions were obtained. 1. In the case of quiet and light snowfall from higher clouds of layer type, non-rimed snow crystals are charged negatively by a mechanism similar to Wilson's induction mechanism, and the so called inverse relation between positive surface electric field and negative charge on falling snow crystals is observed. 2. In the case of heavy snowfall from such as nimbocumulus clouds, graupel or rimed snow particles are charged positively at temperature higher than -10°C by friction with non-rimed snow crystals which are charged negatively. A negative surface electric field is formed by the removement of positive charge on falling graupel from cloud layer, and thus inverse relation (positive snowfall under negative surface electric field) is observed. 3. In the case of showery snowfall, negative and positive sharp peaks occur in the electric field record. These peaks are produced by the change of local space charge near the observation point. The mechanism of charge generation is the same as in 2.