Abstract
A classification of monthly and 5-day mean 500 mb height patterns is carried out for the period 1946-19'10, by the use of the zonal index anomalies in the four quadrants of the Northern Hemisphere. The patterns are classified into three types, two foundamental circulation types, Z and M, and a sub-circulation type S. These are further classified into subdivisions, that is, 10 fundamental types and 6 sub-types. The model patterns for these types are constructed by making use of the composite maps.
Some relationships between the typical patterns of the Northern Hemisphere and the recent climate in the world are studied, by using the result of this classification. It is found that the frequency and presistence of patterns in each type have a close relation to the features of climate in the world and that the new set of types is very useful for a study of the climatic change in Japan and also for practical long-range forecasting. In this paper, the patterns in the Northern
