Partition of the North Pacific Ocean based on similarity in temporal variations of the SST anomaly

In order to understand the characteristics of large-scale SST anomaly fluctuations, a cluster analysis with respect to similarities in their temporal variation is made of the SST anomaly field in the North Pacific. This analysis can extract a subdomain of coherent SST anomaly fluctuations in the middle latitude western part of the North Pacific (REGION A), although previous EOF studies of the SST anomaly in the North Pacific did not extract such a subdomain. In addition, the North Pacific Ocean is divided into four major subdomains, that is, the northwestern subdomain (REGION A), the western tropical subdomain (REGION B), the central North Pacific (REGION C), and the eastern boundary region (REGION D). Oceanic and atmospheric conditions characterizing such subdomains are discussed.