Climatic Reconstruction in Historical Times Based on Weather Records

Recent studies on the climatic reconstruction of Japan based on historical weather records are reviewed. On the whole, they may be classified into two categories according to their approaches. One approach is to examine long-term climatic fluctuations at a particular place on the basis of continual weather records. Another approach is to construct spatial weather features for a particular period (e. g., famine years) by using as many weather records as possible. In any case, a problem is that how we can transform such qualitative data as historical weather records into the quantitative climatic data which are comparable with instrumental data. An attempt is also made to derive the characteristics of weather situations in historical times of Japan, especially in the Little Ice Age, from various studies in the field of historical climatology. Finally, future prospects for the climatic reconstruction in historical times are summarized by making reference to the recent studies in other countries