Vol. 9(4) April 2016
A mathematical Tool to recognize Ionospheric Tsunami
due to Tropical Cyclone: A case such as Typhoon Nakri on 29 May 2008
Lin Jyh-Woei
In this paper a mathematical tool called two dimensional
Principal Component Analysis (2DPCA) is used to determine total electron content
(TEC) anomalies in the ionosphere for a Tropical Cyclone such as the Nakri Typhoon
on 29 May, 2008 (UTC). 2DPCA is applied to the global ionospheric TEC data with
transforms conducted for the time period 12:00 to 14:00 UT on 29 May 2008 when the
wind was most intense. Results show that at a height of approximately 150-200 km,
the TEC anomaly is more localized; however its intensity increases with height and
becomes more widespread. The TEC anomaly is akin to an ionospheric tsunami. Potential
causes of the results are discussed with emphasis given to vertical acoustic gravity
waves. The approximate position of the typhoon’s eye can be detected if the TEC
data are divided into fine enough maps with adequate spatial-resolution at GPS-TEC
receivers. This implies that the trace of the typhoon is caught using 2DPCA.
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