[A-AS08] General Meteorology

[AAS08-P10] Relationships between typhoon track and the distribution of atmospheric pressure and sea surface temperature

*Izumi Tadamasa¹, Makoto Inoue² (1.Graduate school, Akita Prefectural University, 2.Akita Prefectural University)

Keywords:typhoon, North Pacific High, statistical analysis, sea surface temperature

Typically, the typhoons that make landfall in Japan for summer to autumn were reported to move northwestward in tropics and then change the direction to the northeast around Okinawa. On the other hand, there were a few typhoons whose tracks are completely different from normal. It is difficult to predict tracks of these typhoons with high accuracy. The purpose of this study is to clarify the mechanism for typhoon that makes an irregular track to improve forecast accuracy. Based on the statistical data by the Japan Meteorological Agency (JMA), frequent typhoon years in Japan were extracted from the 37 year (1987-2023) sample. We investigated the characteristics of atmospheric pressure field in frequent typhoon years using the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data. As a result, significant low-pressure anomalies were observed in the Pacific side of Eastern Japan, and significant high-pressure anomalies were seen in the northeastern part of the Sea of Okhotsk. Therefore, the extension of the North Pacific High to Japan in frequent typhoon years was weaker than that in the climatological field. This anomaly distribution may be favorable for landfall of the typhoon in Japan. In addition, we will also present the analysis result on the sea surface temperature.