Hisashi Nakamura, a professor in climate dynamics at the University of Tokyo, said that among the westerly winds, meandering of the subtropical jet stream that flows at around 40 to 45 degrees north latitude has played a large part in the weather changes. This phenomenon, which begins near Europe and weaves repeatedly over Eurasia, occurs in summer and frequently brings abnormal weather to Japan, including extreme heat. Since it involves the atmospheres of both Europe and Asia, it is sometimes called the "Silk Road teleconnection" pattern.