The Key Oceanic Regions Responsible for the Interannual Variability of the Western North Pacific Subtropical High and Associated Mechanisms

The western North Pacific subtropical high (WNPSH) is an important circulation system that impacts the East Asian summer climate. The interannual variability of the WNPSH is modulated by tropical air-sea interaction. In order to make it clear which oceanic regions are crucial to the interannual variability of the WNPSH, the research progresses in this regard in the past decade are reviewed. Based on the review, it is recognized that five oceanic regions are responsible for the interannual variability of the WNPSH in summer, including the equatorial central-eastern Pacific Ocean, tropical Indian Ocean, subtropical western North Pacific, the vicinity of the maritime continent, and the tropical Atlantic Ocean. The mechanisms how the sea surface temperature anomalies (SSTAs) in these regions affect the WNPSH are elaborated. The formation mechanisms for the SSTAs in these five regions are discussed. Strengths and weaknesses of the climate models in simulating and predicting the WNPSH are also documented. Finally, key scientific problems deserving further studies are proposed.