Large-scale structure of the polar solar wind at solar maximum: ULYSSES/URAP observations
Abstract
We outline the recent in situ radio observations obtained by Ulysses during its second fast latitude scan near the 2001 solar maximum. From ~ 72° N, Ulysses was embedded in a continuous fast wind associated with a northern polar coronal hole. During that period, we enlight the variation of the electron density and thermal temperature with the heliocentric distance and latitude, obtained with the quasi-thermal noise spectroscopy method. Since the scaled mass flux is observed roughly constant, we derive the profile of the electron thermal temperature, assuming a simple power-law model. Indeed, we find that the electron density varies as R-2.0+/-0.1 while the thermal temperature varies as R-0.7+/-0.1, in good agreement with the results obtained in polar coronal holes in 1995 near solar minimum.
- Publication:
-
Solar Wind Ten
- Pub Date:
- September 2003
- DOI:
- 10.1063/1.1618541
- Bibcode:
- 2003AIPC..679...59I
- Keywords:
-
- 96.60.Vg;
- 96.60.Pb;
- 96.50.Ci;
- Particle emission solar wind;
- Solar wind plasma;
- sources of solar wind