The authors are indebted to J.-P. Delaboudinière (SoHO-EIT) and R. Schwenn (SoHO-LASCO) for generous data supply and helpful comments. We acknowledge discussions with A. Klassen, A. Mangeney, Z. Mouradian and N. Nitta. The Nançay Radio Observatory is funded by the French Ministry of Education, CNRS, and the Région Centre. The Yohkoh mission is a project of the Institute of Space and Astronautical Science (ISAS) of Japan. It is funded by ISAS, NASA, and the UK Particle Physics and Astronomy Research Council (PPARC). J.I.K. received support from PPARC.
© European Southern Observatory (ESO) 1999
Online publication: June 17, 1999