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Titel |
Daytime descending intermediate layers observed over a sub-tropical Indian station Waltair during low-solar activity period |
VerfasserIn |
K. Niranjan, B. Srivani, V. V. S. Naidu |
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.807-815 |
Datensatznummer |
250016805
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Publikation (Nr.) |
copernicus.org/angeo-28-807-2010.pdf |
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Zusammenfassung |
Study on daytime descending intermediate layer over subtropical Indian
station Waltair (17.7° N, 83.3° E geographic, 6.4° N, 10° E
geomagnetic, 20° N dip) located in the equatorial anomaly
transition region, using an IPS 42 Digital Ionosonde during the low solar
activity year 2004 showed that the layers occur in the altitude range of
140–160 km with maximum occurrence during winter solstice. The layers
observed during daytime occur with a double peak variation throughout the
year with less occurrence probability and shorter duration presence during
forenoon hours. The morning layer descent was associated with a density
increase where as during afternoon hours a decrease in density was observed.
The downward drift velocity was about 8 km/h during morning hours and
between 7–11 km/h during afternoon hours, with a low descent rate of around
4.5 km/h during summer morning hours. The results indicate the presence of a
6 h tide at this location as observed from the characteristics of the
descending layers, unlike at majority of locations where a significant semi
diurnal trend is observed. The study brings out the complex nature of the
tidal interaction at different locations. |
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