Rabl, G. K. F. | Search NASA

NASA NTRS1989

External control of the Saturn kilometric radiation by the solar wind - Comparison between Voyager 1 and 2 observations

The long-term modulation of Saturn's nonthermal radio emission in the kilometric wavelength range has been studied based upon data obtained by Voyagers 1 and 2. A comparison of the ballistic and hydrodynamic propagation of solar wind features from the spacecraft to Saturn allows the uncertainty inherent in the projection to be determined. The results confirm the previous suggestion that momentum, ram pressure, and kinetic energy flux are the primary solar wind parameters that drive the nonthermal radio emission. It is suggested that, under certain conditions and for limited periods of time, the magnetic properties and time derivatives of the solar wind have increased importance.

Rucker, H. O.↗

NASA NTRS1986

Persistence of solar wind features

Using data from the plasma and magnetometer experiments on board the Voyagers 1 and 2 during the approach to Jupiter, solar wind persistence is investigated over the period from January 1978 (Voyager 1 passing by Voyager 2) through February 1979. The trajectories of both spacecraft provided a unique opportunity to study the radial evolution and variation of the solar wind over about 3 AU, and to analyze the persistence of solar wind features along the radially increasing separation distance of both Voyagers. Some emphasis is placed on a period of DOY (day of year) 152 through 212, 1978, in which the observed propagation delay time of solar wind signatures between both Voyagers significantly deviates from the expected delay time. A decrease in the correlation coefficient of the corresponding Voyager 1 and 2 data profiles indicates a remarkable change of the solar wind flow. This period in question coincides to a great extent with the interval V of June-July 1978, selected by STIP (Study of Travelling Interplanetary Phenomena).

Rucker, H. O.↗