The position of the subtropical high in the western Pacific affects the strength of the East Asian summer monsoon. By analyzing data from 1980 to 2010, researchers found that when the high is further west, the monsoon is weaker, and when it is further east, the monsoon is stronger. This shift also impacts other weather patterns in the region, such as the strength of the South Asia high and the development of troughs. The interaction between the subtropical high and the monsoon system plays a crucial role in determining the intensity of the summer monsoon in East Asia.