Open AccessVariations of solar EUV, UV and ionospheric foF2 related to the solar rotation period
Author(s) -
R. P. Kane,
E. R. de Paula,
N. B. Trivedi
Publication year - 1995
Publication title -
annales geophysicae
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.522
H-Index - 93
eISSN - 1432-0576
pISSN - 0992-7689
DOI - 10.1007/s00585-995-0717-4
Subject(s) - solar minimum , ionosphere , solar rotation , solar cycle 22 , atmospheric sciences , sunspot , solar maximum , solar flare , solar cycle , environmental science , physics , solar physics , astrophysics , astronomy , solar wind , plasma , quantum mechanics , magnetic field
Spectral analysis of daily values of various\udsolar indices viz. sunspot number, 10.7-cm flux, H Lyman-α and\ud-β, specific He, Fe and Mg lines and solar X-rays was carried out for\udtwo selected intervals. During interval A (May-August 1978, 123 days) the solar\udindices showed a prominent periodicity near 27 days, while during interval B\ud(January-May 1979, 151 days) the solar indices showed a prominent periodicity\udnear 13 days. For the same intervals, foF2 (max) and foF2\ud(average) during 1000-1500 LT were similarly analysed for the locations\udCachoeira Paulista, SP, Brazil (23°S, 45°W), and Okinawa (26°N, 128°E) and\udKokubunji (36°N, 139°E) in Japan. The 27-day and 13-day periodicities in solar\udindices were reflected in the foF2 series, but in different relative\udproportions at the three locations, probably due to the interference of local\udaerodynamical effects. Some other periodicities were common to solar indices and\udfoF2, while some others were present in the solar indices but not in foF2,\udor vice vers