[M-IS07] Effects of lightning, severe weather and tropical storms

[MIS07-P04] Lightning Activity in Western North Pacific Measured by the V-POTEKA Network and Its Relation to Typhoon Intensity

*佐藤 光輝¹、高橋 幸弘¹、久保田 尚之¹、Lopez Glenn Vincent C.² (1.北海道大学 大学院理学研究院、2.フィリピン科学技術省 先端科学技術研究所)

キーワード：雷活動、台風、直前予測

Lightning activity is the good proxy representing precipitations and the updraft intensities in thunderclouds. Recent studies revealed that the lightning occurrence number in tropical cyclones (TCs) shows clear relation to the intensity development of TCs, whereas the prediction of the typhoon intensity development is very hard even though the recent meteorological model is used. Many countries in the western north Pacific suffer from the attack of TCs (typhoons) and have a strong demand to predict the intensity development of typhoons by a cost-effective methods. Thus, we have developed a new automatic weather and lightning observation system (V-POTEKA) and installed this system in the Philippines, Guam, Palau, Jakarta, Okinawa since September 2017. Using the V-POTEKA data, lightning locations are estimated by using the time-of-arrival geolocation algorithm. We have compared the relation between the lightning activities measured by the V-POTEKA network and the intensity change of the western north Pacific typhoons in the period of 2018-2020. In this 3 years, a total of 81 typhoons occurred. As for the 2018 typhoons, we selected 11 of 29 typhoons and conducted cross-correlation analysis between lightning activities and typhoon intensity development. We confirmed that the time variations of the detected lightning event numbers and typhoon intensities (maximum wind speed and center pressure) are highly correlated. Especially, there is clear time lag (~1.5 days) between lightning activities and typhoon intensities in the category 1-3 typhoons, that is, the peak of lightning activity comes first, then the peak of the typhoon intensity comes next. However, as for the super typhoons (category 5 typhoons), this relation is not always clear. At the presentation, we will also show the detailed results derived from this cross-correlation analysis between lightning activities and intensity development of the 2019, 2020 typhoons.