Interplanetary scintillation observations of interaction regions in the solar wind
- 1University of Wales, Aberystwyth, Wales, EU
- 2University of California, San Diego, California, USA
- 3National Centre for Atmospheric Research, Boulder, Colorado, USA
- 4EISCAT Scientific Association, Sodankylä, Finland, EU
- *Present address: Max-Planck Institut fär Aeronomie, Postfach 20, D-37189 Katlenburg-Lindau, Germany Tel: +49 5556 979 415; fax: +49 5556 979 410; e-mail: email@example.com
Abstract. Co-rotating interaction regions (CIRs) between fast and slow streams of plasma are a prominent feature of the solar wind. Measurements of interplanetary scintillation (IPS) using the three widely separated antennas of the EISCAT facility have been used to detect the compression regions at the leading edges of interaction regions and to determine the location and velocity of the structure. Observations show that interaction regions have developed as close to the Sun as 25–30 solar radii, a result supported by theoretical modelling which shows that the conditions needed for CIRs to develop exist inside 30 solar radii.
Key words. EISCAT · Interplanetary scintillation · Solar Wind