Observations of random and quasi-periodic scintillations at southern mid-latitudes over a solar cycle

Hajkowicz L.A. and Dearden D.J. (1988) Observations of random and quasi-periodic scintillations at southern mid-latitudes over a solar cycle. Journal of Atmospheric and Terrestrial Physics, 50 6: 511-517. doi:10.1016/0021-9169(88)90109-2


Author Hajkowicz L.A.
Dearden D.J.
Title Observations of random and quasi-periodic scintillations at southern mid-latitudes over a solar cycle
Journal name Journal of Atmospheric and Terrestrial Physics
ISSN 0021-9169
Publication date 1988-01-01
Sub-type Article (original research)
DOI 10.1016/0021-9169(88)90109-2
Volume 50
Issue 6
Start page 511
End page 517
Total pages 7
Subject 1902 Film, Television and Digital Media
1908 Geophysics
Abstract An extended period (1973-1985) of recording of random and Fresnel type quasi-periodic (QP) scintillations in southern mid-latitudes, using satellite beacon transmissions at a frequency of 150 MHz, has provided some new information on the morphology of scintillation-producing irregularities. It has become evident that a pronounced daytime increase of the random type of scintillations in the southern winter (at 1200-1600 LT) occurs throughout the solar cycle and becomes a distinct daytime maximum during the years of sunspot minimum. Scintillations are most intense in the pre-midnight period in the southern summer (2000-2400 LT). There is a gradual decline in scintillation activity by about 40% from the period of sunspot maximum to the period of sunspot minimum. It appears that a specific type of sporadic-E, so-called constant height Es (Esc), is responsible for daytime scintillation activity in winter. Night-time scintillations are strongly correlated with the presence of the range-spread type of spread-F, but not so with the frequency-spread type. There are two peaks in the occurrence of QP scintillations, predominantly in the southern summer: in the late morning (0800-1000 LT) and in the pre-midnight period (2000-2200 LT). The daytime QP scintillations occur mainly polewards of the station, whereas the night-time scintillations are recorded predominantly equatorwards. There is a distinct increase in the occurrence number of QP scintillations with a decrease in the sunspot number.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: Scopus Import - Archived
 
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