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In the previous papers (1968, 1969), the present writer concluded that the winter temperature in Japan still kept its increasing trend until the end of 1960's while in Europe and North America it had already ceased in 1940's. In this study, the subsequent change up to 1970 are examined with an important result that the winter temperature had begun to fall in Japan at the beginning of 1960's (Fig. 1) while for the summer temperature its decreasing trend had been found thus early in 1940's. A schematic model for these changes is shown in Fig. 3. Before the discussion on main subject, meaning of trend index adopted here and homo-genuity of the temperature records are closely checked. After these preliminary works, dis-tribution maps of the trend indices for winter and summer temperatures during the two periods 1941-60, 1960-70 are constructed (Fig. 4-7). For the climatological explanation of these distribution pattern, some dynamical considerations are given. The main results obtained in this study are as follows: 1) For the representation of the winter cold and summer heat in Japan, the writer adopts the mean temperatures of the coldest and warmest months respectively, because their secular changes are nearly parallel to those of the mean minimum and maximum temperatures of the respective months and the accumulated sum of monthly temperatures lower than critical levels during the whole winter or summer months. Hence they are likely to represent the total state of winter and summer temperatures in the respective years. In a study of temperature fluctuations, mean temperatures for a definite interval, say every five or ten years are often used. However those higher and lower means do not necessarily represent its rising and falling tendency respectively as clearly indicated in Fig. 2. That is, a general trend of temperature cannot be expressed merely by their mean values for the respective periods. Among indices available for us to express such a kind of phenomena, the writer selected the trend index devised by Dr. E. Suzuki as the most preferable one for the purpose of this study. With reference to this index, the writer commented in the previous paper on the recent heavy rainfall in Japan and hence it is omitted here. (See January number of this Journal in 1972, pp. 1-12) 2) Temperature rise is not only caused by the climatic change in a wide area, but in large cities also is highly controlled by the expansion of built-up areas together with the increase of population. Of course, urban influence on the increasing rate of temperature is not the same at different places. With respect to this subject, the writer obtained an important result in the former study (1968) that a relation between the increasing rate of temperature and population growth in Japan is not the same in large cities with their population over 500, 000 as compared with other smaller cities. On the other hand, in the sparsely populated areas such as high mountain tops, protruding ends of promontories, small islands etc., temperature rise due to an artificial heat might be negligible and therefore a true state of temperature variation can be distinctly found. For this reason, seventy two stations selected for this study are classified into the following seven groups by their geographical locations and population : A) Gigant cities with a population over 2, 000, 000 .(Tokyo, Osaka and Nagoya) B) Large cities with a population over 500, 000 (Sapporo, Sendai, Hiroshima and Fukuoka) C) Middle class cities with a population 300, 000_??_500, 000 (Kanazawa and other 12 cities) D) Small cities or towns with a population less than 50, 000 (28 places) E) Stations at the high mountain tops such as Ibukiyama (5) F) Stations at the protruding end of promontories (5) G) Stations at the small islands (4)

The second objective of GARP—climate research—comes more and more into the focus of the scientific community, and the use of satellites and spacelabs to acquire the necessary data is discussed widely. From an inspection of the results of current climate model computations it is attempted in this paper to deduce the criticality of atmospheric parameters with respect to climate and to deduce the required measuring accuracy to get useful data for further climate studies. It emerges that some quantities as the solar flux and albedo have to be determined to better than 1%, and that much improved global information about particles, clouds and gas distribution is necessary. The impact of these requirements on future satellite systems is discussed. One result is the need for comparative and calibrating spacelab missions as well as for adequate ground truth or in situ operations.

The author reviews the work done by himself and by Bezrukova-and Rubashev at the Pulkovo Observatory in relating fluctuations in the characteristics of the general circulation of the earth's atmosphere over the Northern Hemisphere to fluctuations in solar activity, on the one hand, and to climatic fluctuations, on the other. The general circulation of the atmosphere is thus found to meet the requirements of an intermediate link in the research system: sun—climatic change. This paper was read at the New York conference on solar variations, climatic change and related geophysical problems in January 1961.

We describe in this paper a set of general circulation model experiments on possible climate changes caused by man's generation of thermal energy or pollution. Three experiments were carried out: one in which we introduced only a small initial error, one in which we added the expected ultimate levels of thermal energy generation, and one in which we added a negative amount of thermal energy. In an three experiments, we obtained the same results, indicating that the thermal pollution effect is probably small compared to the natural fluctuations of the model. We also discuss some limitations of the present model for inferring the proper climatic-change response.