Historical Review of Research Activities toward Typhoons/Hurricanes Modification in Japan and the United States

Abstract

This study summarizes the discussions on typhoons or hurricanes modification in Japan and the United States (US) from the 1940s to the present, based on a survey of past literature and interviews with relevant personnel. Research on hurricane modification began approximately 80 years ago with Project Cirrus (1947–1952) and Project Stormfury (1962–1983) run by the US government. This project was initiated following a US proposal to Japan in 1965, which aimed to conduct field experiments using cloud seeding techniques for typhoons over the western North Pacific. The proposal sparked in-depth discussions in both academia and the National Diet of Japan. In 1971, the typhoon committee conditionally approved the field experiment in the western North Pacific, but ultimately, the typhoon field experiment was not conducted. This paper identifies the factors that led to the decision not to proceed with the typhoon field experiment despite significant progress, as well as the reasons underlying the decline of typhoon modification and general weather modification research in Japan from that period onward.