Analysis of Ionospheric TEC Anomalies during Super Typhoons Megi and Meranti

Abstract

Sun, J.L.; Zhang, Z.Y.; Liu, X.; Zhang, C., Mou, Z.H., 2020. Analysis of ionospheric TEC anomalies during super typhoons Megi and Meranti. In: Bai, X. and Zhou, H. (eds.), Advances in Water Resources, Environmental Protection, and Sustainable Development. Journal of Coastal Research, Special Issue No. 115, pp. 692-695. Coconut Creek (Florida), ISSN 0749-0208.In this paper, we detected and analyzed ionospheric anomalies during the 2016 super typhoons Megi and Meranti using the sliding interquartile range method applied to the ionospheric total electron content (TEC) grid data from the Global Ionospheric Model (GIM) provided by the Center for Orbit Determination in Europe (CODE). We found that ionospheric TEC anomalies occurred 2 days before the origination of super typhoon Megi. The anomalies occurred from 02:00 to 12:00 local time over a period of 10 h, with a maximum outlier of 12 TEC units over the typhoon center. Anomalies occurred in the ionosphere over both the area near the typhoon center and the corresponding equatorial magnetic conjugate region. The anomalies in both areas showed approximately the same trends. It is very likely that the disturbances from the ionospheric anomalies over the typhoon center were one of the precursors for the typhoon event. Similar ionospheric anomalies also occurred in the ionosphere 2 days before the formation and development of super typhoon Meranti. The global ionospheric TEC distribution was even more complex on that day. The existence of multiple peaks and valleys in the maximum outlier near the typhoon center was possibly associated with the position of the typhoon center and the GIM grid points or the wind speeds over the typhoon center.