°This is an observational study of a monsoon depression during its westward passage across India. We present a study based on available conventional radiosonde rawinsonde pilot balloon and commercial aircraft wind reports during August, 1968. Besides showing conventional analysis of the motion and thermal fields, we also show a number of vertical structure diagrams. The important findings of the observational study are that the horizontal scale of the depression is about 2000 km, the vertical scale about 10 km, its westward speed of motion about 5° longitude /day. The monsoon depression is an intense closed vortex that has horizontal wind speeds of about 10 to 15 mps and its closed circulation extends to about 9 km in the vertical. A narrow vertical tube of cyclonic vorticity with a horizontal scale≈1000 km and extending up to 9 km is a characteristic feature of this circulation. This depresson formed over the northern part of the Bay of Bengal and dissipated over the Arabian Sea. The vortex has a very well defined cold core in the lower troposphere and a warm core above 500mb. To the west of the cold core there exists a very intense warm core in the lower troposphere. The intense warm core is a con-sequence of advection of desert air by the storm circulation. Vertical motions show rising motion west of i.e., ahead of the trough line and descending motion to the rear. The westward motion of the monsoon depression is related to intense low level convergence in the region of the strongest ascending motion. In this region rainfall rates exceed 10cm/24 hrs during the passage of the disturbance. The analysis and observational structure derived in this study is examined in a second part of this paper, where the dynamics, energetics, and numerical prediction aspects are stressed.
The time change in position and size of cumulus clouds formed periodically in the lee of an island was measured by the stereophotogrammetric method. It was found that the observed cloud interval was different from the cloud interval calculated with the occurrence period of the individual cloud. The mechanism for the difference was discussed.
In this paper an investigation is made of the non-linear effects on mesoscale convection, It is shown that the temperature dependence of viscosity and conductivity may only have a marginal effect on the character of the convective cells. Both open and closed type cells are investigated and it is shown that those of the first type can be more efficient in carrying the heat flux than the second for certain types of boundary conditions.
In their previous paper, the authors (1973a, 1973b) analyzed the seasonal variation of infant mortality during 1961-67 by the Census Method II X-11 and found that the death peak has tangibly declined in winter, whereas the summer hill has been getting relatively higher. In the present report, they want to present results of their new investigation: Is this phenomenon an omnipresent one in Japan or confined to some parts of the country? The variation of the seasonal component of the death rate isolated by the X-11 method is considered as the real seasonal variation of infant mortality. It is thus found that during 1968-72 the death rate has got considerably moderate on the whole in all parts of the country, that such moderation has been particularly remarkable in highly urbanized regions, such as Tokyo, Aichi, Osaka, Hiroshima and Fukuoka, and that two peaks in winter and summer have become nearly equal to each other. Such lowering of the winter upcurve appears to have come from the recent improvement of room heating in the cold months. The relative prominence of the summer hill, however, cannot be explained so easily as the lowering of the winter summit. In recent years. mortality has visibly declined due to the development of medical science and technology, the marked improvement of living conditions and other favorable factors, but there still remains some causes for morbidity and mortality which cannot be eliminated completely, including some severe environmental elements like cold in winter and heat in summer. This is the very reason why deaths invariably increase in the cold and hot months.