Geomagnetic Storm Effect on F2-Region Ionosphere during 2012 at Low- and Mid-Latitude-Latitude Stations in the Southern Hemisphere

نویسندگان

چکیده

The ionospheric effects of six intense geomagnetic storms with Dst index ≤ −100 nT that occurred in 2012 were studied at a low-latitude station, Darwin (Geomagnetic coordinates, 21.96° S, 202.84° E), low-mid-latitude Townsville (28.95° 220.72° and mid-latitude Canberra (45.65° 226.30° the Australian Region, by analyzing storm–time variations critical frequency F2-region (foF2). Out storms, storm 23–24 April did not produce any effect. 30 September–3 October (minimum = −122 nT) 7–10 −109 are presented as case studies same analysis was done for other four storms. October, during its main phase, produced positive all three stations maximum percentage increase foF2 (∆foF2%) 45.3% whereas recovery phase it negative ∆foF2% −63.5% associated decrease virtual height F-layer (h’F). strong long-duration an h’F −65.1% Townsville. comparatively longer duration more pronounced comparison to only showed two (14–15 July October) station indicating prompt penetrating electric fields (PPEFs) these propagate low latitude. accounted PPEFs affecting equatorial E × B drifts traveling disturbances due joule heating high latitudes. disturbance dynamo overshielding field storm-induced circulation from latitudes toward leading changes natural gas composition [O/N2] ratio.

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ژورنال

عنوان ژورنال: Atmosphere

سال: 2022

ISSN: ['2073-4433']

DOI: https://doi.org/10.3390/atmos13030480