Mathematics – Probability
Scientific paper
Dec 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995aas...18711603g&link_type=abstract
American Astronomical Society, 187th AAS Meeting, #116.03; Bulletin of the American Astronomical Society, Vol. 27, p.1447
Mathematics
Probability
Scientific paper
It has long been known that the occurrence probability per apparition of the Jovian decametric radiation observed from Earth undergoes a cyclic variation having a period on the order of a decade. Although it had first been suggested that the occurrence probability was inversely correlated with the smoothed sunspot number, Carr et al. (Radio Science, 5, 495, 1970) demonstrated that the correlation with the Jovicentric declination of Earth (DE) is much closer. (The period of the DE variation is 12 years, while that of the sunspot number is about 11 years on the average.) In the 25 years since the Carr et al. paper, no further observational studies of the long-term periodicity in occurrence probability have been reported. In this paper we present preliminary results of a much more thorough investigation of the long-term occurrence probability variation based on the analysis of some 40 years of Jovian decametric observations from the University of Florida Radio Observatory and 10 years of observations from the Maipu Radio Astronomy Observatory in Chile. It appears that the occurrence probability per apparition is correlated jointly with DE and sunspot number. The decametric activity almost disappears during apparitions for which either DE is less than about -2.5 (its range is from approximately -3.3 to +3.4), or the sunspot number is greater than about 100. Our empirical model based on both DE and sunspot number provides a good fit to the observed occurrence probability data. We suggest that 1) the DE control is a geometrical effect resulting from the sharp lower edge of an emission beam that corotates with the source (Earth remaining just outside the beam for the most negative values of DE but not for the more positive ones), and 2) the observed decrease in occurrence probability with increasing sunspot number results from the increased ionization in the source region (from solar UV) which increases the ratio fp/fc toward the limit of about 0.1 (this is the limit at which the cyclotron maser radio emission mechanism ceases to operate). There are other possible explanations for the latter effect.
Carr Thomas D.
Garcia Nancy L.
Higgins Charles A.
Reyes Francisco
No associations
LandOfFree
Joint control of terrestrially observed Jovian decametric activity by DE and Solar UV. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Joint control of terrestrially observed Jovian decametric activity by DE and Solar UV., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Joint control of terrestrially observed Jovian decametric activity by DE and Solar UV. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1257009