Some relationships between solar X-ray bursts and SPA's produced on VLF propagation in the lower ionosphere
Tipo
Artigo
Data de publicação
1969
Periódico
Solar Physics
Citações (Scopus)
17
Autores
Kaufmann P.
Paes de Barros M.H.
Paes de Barros M.H.
Orientador
Título da Revista
ISSN da Revista
Título de Volume
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Resumo
This paper discusses SPA's measured at long VLF propagation paths in the lower ionosphere and their association with solar X-ray bursts observed by USNRL satellites in the 0-3 Å, 0-8 Å and 8-20 Å bands. Excellent correlations were found between the SPA importances (in degrees per Mm) and the logarithm of the X-ray burst peak intensities. A hardening of the X-ray burst spectra is evident for increasing importance of SPA's; the threshold energy required for the occurrence of such anomalies was estimated, it is 4.3×10-5 ergs cm-2 sec-1 in the main ionizing band of 0-3 Å. It was also possible to derive the effective recombination coefficient at the normal D-region height of 70 km, this being αr≈6×10-6 cm3 sec-1; furthermore ion production rates were estimated during SPA's at heights below the reference level. © 1969 D. Reidel Publishing Company.