Ionospheric Disturbances Observed From a Single GPS Station in Hong Kong During the Passage of Super Typhoon Hato in 2017

Abstract

The powerful convection in the lower atmosphere, for example, tropical cyclones (TCs), has a high probability of causing ionospheric disturbances. We observed evident ionospheric disturbances during the passage of Super Typhoon Hato in 2017 by analyzing the highest elevation vertical total electron content (HeVTEC) time series, that is, the VTEC from the Global Positioning System (GPS) satellite with the highest elevation at each epoch, retrieved from a single GPS station in Hong Kong. The results demonstrate that the daily maximum of HeVTEC time series on each day during the TC period experienced a large fluctuation ranging from 33.5 TEC unit (TECU) to the peak value 62.0 TECU. The peak value 62.0 TECU occurred on the TC landfall day 23 August 2017, approximately twice as high as that of non‐TC‐impacted days. We also found that the TEC spatial gradients above the landfall area increased by around 50% and 200% in the north‐to‐south and west‐to‐east directions, respectively. We also examined the daily mean bias (MB) of VTEC above Hong Kong with respect to the mean VTEC during the past 27 days from 20 July to 15 August in 2017. The largest VTEC MB was observed in the west of the landfall area along the TC moving direction, on the TC landfall day. Our findings provided the evidence that the Hato's landfall over the coast near Hong Kong caused the apparent ionospheric disturbances above the landfall area.

The Two‐Dimensional and Three‐Dimensional Structures Concerning the Traveling Ionospheric Disturbances Over Japan Caused by Typhoon Faxai

“…More recently, Yu et al. (2022) studied evident TEC fluctuations ranging from 33.5 TECU to the peak value of 62.0 TECU during the passage of Super Typhoon Hato in 2017 based on a single GPS station in Hong Kong.…”

Ionosphere Response to the simultaneous and consecutive occurrence of Geomagnetic Storm and Lightning at various intensities in a Low Latitude Region

“…For example, Ratovsky et al (2022) attributed the source of same extreme ionospheric events to geomagnetic activity and sudden stratospheric warming (SSW). Also, Yu et al (2022) reported an increase to about 60TECu during the passage of Typhoon Hato. Other weather events have also been reported to have such similar increment (Suparta & Yusop, 2017).…”

Revisiting the Ionospheric Disturbances Over Low Latitude Region of China During Super Typhoon Hato

“…On the day of landfall, the ionospheric TEC over Hong Kong region experienced great enhancement, the peak value 62.0 TECu occurred on the landfall day, approximately twice as high as that of non-typhoon impacted days, which was considered to be related to Hato (Yu et al, 2022). It should be noted that Yu et al (2022) relies solely on highelevation angle data from stations in Hong Kong region, which may result in limited spatial coverage and incomplete information about the ionospheric response. It is noteworthy that Typhoon Hato made landfall while a weak magnetic storm was occurring.…”

“…Studies on ionospheric variations during typhoon passage in East Asian, Australian, and North American regions shown that these regions sometimes experience positive or negative deviations in TEC during typhoon events (W. Li et al, 2017Li et al, , 2018Mao et al, 2010;Yu et al, 2022). It should be noted that due to the complex variability of the ionosphere and limitations in data processing methods, some results of these studies may also carry some uncertainty in determining the precise extent of deviation caused by the impact of typhoons.…”

“…On 23 August 2017, Typhoon Hato landed on the southern coast of Guangdong Province, China. On the day of landfall, the ionospheric TEC over Hong Kong region experienced great enhancement, the peak value 62.0 TECu occurred on the landfall day, approximately twice as high as that of non‐typhoon impacted days, which was considered to be related to Hato (Yu et al., 2022). It should be noted that Yu et al.…”