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| Titel |
Time delay and duration of ionospheric total electron content responses to geomagnetic disturbances |
| VerfasserIn |
J. Liu, B. Zhao, L. Liu |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 28, no. 3 ; Nr. 28, no. 3 (2010-03-18), S.795-805 |
| Datensatznummer |
250016804
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| Publikation (Nr.) |
 copernicus.org/angeo-28-795-2010.pdf |
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| Zusammenfassung |
Although positive and negative signatures of ionospheric
storms have been reported many times, global characteristics such as the
time of occurrence, time delay and duration as well as their relations to
the intensity of the ionospheric storms have not received enough attention.
The 10 years of global ionosphere maps (GIMs) of total electron content
(TEC) retrieved at Jet Propulsion Laboratory (JPL) were used to conduct a
statistical study of the time delay of the ionospheric responses to
geomagnetic disturbances. Our results show that the time delays between
geomagnetic disturbances and TEC responses depend on season, magnetic
local time and magnetic latitude. In the summer hemisphere at mid- and high
latitudes, the negative storm effects can propagate to the low latitudes at
post-midnight to the morning sector with a time delay of 4–7 h. As the
earth rotates to the sunlight, negative phase retreats to higher latitudes
and starts to extend to the lower latitude toward midnight sector. In the
winter hemisphere during the daytime and after sunset at mid- and low
latitudes, the negative phase appearance time is delayed from 1–10 h
depending on the local time, latitude and storm intensity compared to the
same area in the summer hemisphere. The quick response of positive phase can
be observed at the auroral area in the night-side of the winter hemisphere.
At the low latitudes during the dawn-noon sector, the ionospheric negative
phase responses quickly with time delays of 5–7 h in both equinoctial
and solsticial months.
Our results also manifest that there is a positive correlation between the
intensity of geomagnetic disturbances and the time duration of both the
positive phase and negative phase. The durations of both negative phase and
positive phase have clear latitudinal, seasonal and magnetic local time
(MLT) dependence. In the winter hemisphere, long durations for the positive
phase are 8–11 h and 12–14 h during the daytime at middle and high
latitudes for 20≤Ap<40 and Ap≥40. |
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