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Measuring the acceleration profile of the slow solar wind using EISCAT,
MERLIN and SOHO/LASCO observations
A.R. Breen, D. Biesecker, A. Canals, C.A. Jordan, S.J. Tappin, P.Thomasson
and P.J.S. Williams
A series of simultaneous measurements of the velocity of the slow
solar wind were made in May 1999, involving observations of
interplanetary scintillation from EISCAT (0.93 GHz) and MERLIN (1.62
and 5 GHz) and high-cadence white-light measurements from the C3 LASCO
coronagraph on SOHO. The fields of view of the instruments
overlapped, with simultaneous observations of the same regions being
made by EISCAT and MERLIN and by MERLIN and LASCO. This makes it
possible to compare the results from the different instruments with a
high degree of confidence. Initial results from MERLIN and EISCAT
interplanetary scintillation measurements clearly show that the slow
wind velocity increases from ca. 100 km/s at a heliocentric distance of 8
solar radii to ca. 180 km/s by 13 solar radii, reaching a cruising
velocity of ca. 300 km/s inside 31 solar radii. In this presentation we
compare these results with EISCAT measurements further away from the
Sun and LASCO velocities closer in.
(Paper presented by Prof. P.J.S. Williams, Cardiff)
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