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Session 34 - Solar System.
Display session, Tuesday, June 11
In this paper we present results of a study of over 30 years of Jovian decameter--wavelength observations from the University of Florida Radio Observatory and the Maipu Radio Astronomy Observatory in Chile. The occurrence probability per apparition of Jovian decametric radiation observed from Earth undergoes a cyclic variation. This variation is strongly correlated with the Jovicentric declination of the Earth (D_E) which has a period of 12 years. Over the 7 degree range of D_E the yearly averaged occurrence probability for the non Io related A source can vary by over a factor of ten. We suggest that the D_E control is a geometrical effect resulting from the sharp lower edge of an emission beam that corotates with the source. The Earth remains just outside the beam for the most negative values of D_E but not for the more positive ones. We are using a rotating emission beam model to generate synthetic probability histograms in order to determine whether the observed D_E effect can be explained by this simple model.
Program listing for Tuesday