Sequential sporadic-E layers at low latitudes in the Indian sector

Autor: P. T. Jayachandran, P. Sri Ram, P. V. S. Rama Rao, V. V. Somayajulu
Jazyk: angličtina
Rok vydání: 1999
Předmět:
Zdroj: Annales Geophysicae, Vol 17, Pp 519-525 (1999)
Druh dokumentu: article
ISSN: 0992-7689
1432-0576
DOI: 10.1007/s00585-999-0519-1
Popis: A study of the formation and movement of sequential Sporadic-E layers observed during the night-time hours at two Indian low-latitude stations, SHAR (dip 10°N) and Waltair (dip 20°N) shows that the layer are formed around 19:00 h. IST at altitudes of ~180 km. They descend to the normal E-region altitude of about 100 km in three to four hours and becomes blanketing type of Es before they disappear. However, the absence of these descending layers at an equatorial station, Trivandrum (dip 2°N) gives the experimental evidence for wind shear theory. The meridional neutral wind derived from the height variation of the F-layer showed significant poleward wind during the descent of these layers. Hence it is inferred that these layers are formed as a consequence of the convergence of plasma by the poleward wind and the equatorward propagating gravity waves (inferred from the height fluctuations of F-layer).Key words. Ionosphere (active experiments; equatorial ionosphere · ionospheric irregularities)
Databáze: Directory of Open Access Journals
Externí odkaz: