Measurements of the solar wind over a wide range of heliocentric distances- a comparison of results from the first three, Whole Sun Months

Go-ordinated observations of the Sun and inner heliosphere using a large nu mber of space- and ground-based instruments were carried out in August-Sept ember 1996, August 1998 and August-September 1999 as the first, second and third Whole Sun Months. These observations provided unprecedented cover of the Sun and inner heliosphere at solar minimum (1996) and during the rising phase of the new solar cycle (1998, 1999). In this paper we review the obs ervations made during the three Whole Sun Months and consider the changes i n the large-scale structure of the heliosphere seen over the four years. (C ) 2000 Elsevier Science Ltd. All rights reserved.