We consider a stratified compressible atmosphere restrained by gravity, in which thermal radiation is transferred by means of vibrational motions of water vapor and carbon dioxide molecules. A set of linearized equations is formulated describing the atmosphere driven by external heating with radiative energy dissipation. From an analysis of the solution, the following conclusions were obtained. Radiative dissipation is appreciable at least for global-scale motion, but if the external heating changes rapidly or slowly, the dissipation may be negligible. Radiative dissipation is important in the beginning phase of water vapor condensation. However, once a cloud is formed in the atmosphere, it encloses a region which is radiatively ineffective and dissipation is confined to a thin layer near the cloud surface.
The barometric tides, solar and lunar, at the top of Mt. Fuji, are determined by Chapman-Miller method from 20 year hourly data, 1932 through 1952. As to the lunar semidiurnal tides, determinations of the annual mean and of the summer season are both satisfactory, while the winter and the spring-autumn tide determinations are not satisfactory.
Thermal convection in a shear flow varying the direction as well as the speed with respect to height is investigated by means of the perturbation analysis under the Boussinesq approxima-tion. A particular attention is focused on characteristic band structure of thermal convection in relation to the basic flow in which the convection is superimposed. Two different types of unstable perturbations may be found. One originates from thermal instability and the other is in essence of inertial origin. The thermal instability yields a preferred mode of convection roll along which the vertical shear of the velocity component of the basic flow perpendicular to the roll axis is a minimum.
Some techniques are described for objectively analyzing atmospheric variables, particularlywinds and cloud motions, and for refining the analyses to improve their meteorological value.An example shows how tropical cloud patterns observed by satellites can be used to modifyanalyses of vorticity and divergence fields and the associated winds. Methods for balancingdivergence in the vertical and for numerical advection were developed for use in numerical models; some preliminary forecast results are illustrated. A proposed plan for combining various types of satellite and conventional data for input to tropical numerical prediction modus is presented.
A composite and individual years analysis of the large-scale anomalies in the ice limit in the Okhotsk Sea during the December-March quarter, was made in relation to the contemporary and following April-June, July-September, October-December pressure distribution, storm frequency, temperature and precipitation in northern Japan and Far Eastern USSR. The results obtained show that years with severe (light) ice conditions in the Okhotsk Sea are associated with a greater (lesser) frequency of storms, below (above) average temperatures and lighter (heavier) precipitation in northern Japan and Far Eastern USSR in the December- March and also the following April-June periods in keeping with the temporal coherence of the circulation or its persistence. The results obtained further show a complex pattern of temperature and rainfall in the July- September quarter as a reaction to the imbalance in the circulation imposed by the inertia during the preceding December-June period; and a pattern of circulation, temperature and precipitation the following October-December quarter similar to that in the preceding December- June period as a reassertion of the original pattern due to the still unexpended inertia, and hence, of significance for foreshadowing (in limited cases) the April-June and October-December weather of northern Japan and Far Eastern USSR, from a consideration of the ice conditions the previous December-March period. A similar analysis based on anomalies of sea surface temperatures off northeastern Japan showed little relationship.
The characteristics of echo distribution in the Baiu Front are described by constructing multi-radar composite echo maps covering the western and central Japan Islands during three days period from July 03 to July 06, 1969. The purpose of this study is to describe the features of the echo distribution within an large area covering a whole wave-length of the wave cyclone along the Baiu Front. It is shown that the echoes are organized into medium-scale echo clusters in the frontal zone. The spacing between these clusters is several hundereds km. The echo clusters which are located to the east of the synoptic-scale cyclone develop remarkably and are associated with heavy rainfalls. The surface analysis shows the isallobaric low and cyclonic wind circulation within the developed medium-scale echo clusters.
It is shown that the long-period means of the transfers of momentum, sensible heat and water vapor in the air-sea interface may be expressed by several terms. The first term is the same expression as the so-called bulk formula making use of the transfer coefficient known from the micrometeorological observations. The other terms consist of the wind velocity variance, of the covariances between the wind velocity and sea-air temperature difference and between the wind velocity and sea-air water vapor pressure difference, and of the third-order correlation between the wind velocity, temperature and water vapor differences. A statistical analysis was made for the data of wind, temperature and water vapor pressure obtained by twelve weather ships in the Pacific and Atlantic Oceans. And it is concluded that the time averaged quantities of the sensible and the latent heat transfers for the periods shorter than one day may be approximately calculated by the bulk formula using the time averaged values for the same period of the wind velocity and of the sea-air temperature and water vapor differences. On a certain occasion, however, for a period longer than few days the difference between the true heat transfer and the approximate value from calculation may become significant.
The falling velocity of individual snow crystals was ovserved by means of stroboscopic photographs. At the same time, the shape, dimension and mass of those snow crystals were also measured from the photomicrographs of them. The plane type crystals were classified into six groups, namely hexagonal plates, crystals with sectorlike branches, crystals with broad branches, dendritic crystals, stellar crystals and thick plates. Furthermore, the columnar crystals were also observed. Consequently, the relationship between the falling velocity and the dimension of particles was obtained for their several major types of snow crystals, and it was found that the relationship was well explained by the computation method which use the drag coefficient determined by the model experiment.