Anomalous variation in summer tropical cyclone activity by preceding winter Aleutian low oscillation

• Published in: Atmospheric Science Letters
• Main Authors: Choi, Jae‐Won, Cha, Yumi
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: Bering Sea; Okhotsk; Pacific; aleutian low; Sea ice
• Online Access: http://dx.doi.org/10.1002/asl.752; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fasl.752; https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/asl.752

Abstract This research found a high‐positive correlation between Aleutian low oscillation during the winter (November–March) and tropical cyclone ( TC ) genesis frequency during the following summer (July–September) over a 26‐year period (1982–2007). In the years with high Aleutian low oscillation, a number of characteristics were analyzed. In the preceding winter, anomalous pressure patterns, such as south‐low and north‐high at the low level, formed as the center for the regions near 20°N in the western North Pacific. Sea ice concentration was less than the average around the Sea of Okhotsk and the Bering Sea, which weakened the Aleutian Low in this area. This anomalous pressure pattern continued until the following summer, and it reinforced the anomalous easterlies at the mid‐latitudes (20°–40°N) in East Asia and contributed to the high TC passage frequency in the East Asian continent.