Observations of poleward-propagating large-scale traveling ionospheric disturbances in southern China
We report here on two cases of poleward-propagating large-scale traveling ionospheric disturbances (LSTIDs) in China during a medium-scale storm between 27 May and 1 June 2011. The observations were conducted by making use of the Global Positioning System network and ionosondes in China and Sout...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-02-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/31/377/2013/angeo-31-377-2013.pdf |
| Summary: | We report here on two cases of poleward-propagating large-scale traveling
ionospheric disturbances (LSTIDs) in China during a medium-scale storm
between 27 May and 1 June 2011. The observations were conducted by making use
of the Global Positioning System network and ionosondes in China and
Southeast Asia. One northeastward-propagating LSTID occurred on the morning
of 30 May, while the other was observed during the nighttime of 1 June. Both
poleward-traveling LSTIDs occurred during the storm's recovery phase in
southern China's low-latitude region (geomagnetic latitude ~ 7.3–24° N) and experienced severe dissipation during their
propagation from south to north. Although the initial relative amplitude of
the nighttime LSTID was ~ 60% larger than that of the morning event,
the nighttime event dissipated more quickly than the morning event because of
a strong nighttime enhancement in background total electronic content (TEC)
during storm time, which led to strong ion-drag dissipation during the
evening. The poleward-propagating LSTIDs exhibit a narrower latitudinal
range, a smaller amplitude, and a slightly higher elevation compared with the
equatorward-moving LSTIDs observed in the same region. Given these features,
the poleward-propagating LSTIDs were likely excited by some local source near
southern China. Excitation of secondary LSTIDs during the dissipation of some
primary medium-scale disturbances from the lower atmosphere is a possible
mechanism. |
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| ISSN: | 0992-7689 1432-0576 |