Abstract
Comparison of solar wind speed data obtained from the Pioneer 6 and 7 and Vela 3, 4, and 5 satellites from January 1969 through July 1970 has been undertaken. The distribution of measured speeds is similar for all satellites, despite wide separations along the Earth's orbit. For satellite separations (along the Earth's orbit) of 0.5 AU or less, the speeds measured by different satellites are closely correlated, i.e., it is usually possible to predict (to within ± 100 km sec−1) the arrival of a particular solar wind speed at one satellite on the basis of earlier measurements at another. For separations larger than ≈ 1.0 AU it is usually not possible to make accurate predictions in this manner. This appears to be evidence that: (1) the boundary conditions on the coronal expansion at the base of the corona are a sensitive function of latitude and/or (2) the boundary conditions at any one point on the Sun evolve sufficiently in ≈ 4 days to alter significantly the speed of the wind at 1 AU.
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The National Center for Atmospheric Research is sponsored by the National Science Foundation.
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Gosling, J.T. Variations in the solar wind speed along the earth's orbit. Sol Phys 17, 499–508 (1971). https://doi.org/10.1007/BF00150051
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DOI: https://doi.org/10.1007/BF00150051