Comparing High-Resolution MHD Simulations of the Present and Preceding Solar Minima
Abstract
It is now evident that the present solar minimum is characterized by unusual properties compared with those of recent solar space-age minima. In particular, when compared with the previous solar minimum (which occurred in 1996), the current cycle has an increased incidence of spotless days, a decreased polar magnetic field strength, decreased in situ magnetic field measurements at Earth orbit and Ulysses, and a decreased solar wind pressure. The present minimum is also characterized by a greater incidence of small equatorial coronal holes that do not visibly connect with the polar coronal holes. We compare high-resolution 3D MHD simulations of the corona during these two intervals to understand the nature of the difference between the present and previous solar minima. To minimize differences in the comparison, our simulations are based on magnetic field data measured with the same instrument, namely the MDI instrument aboard SOHO. We will use these simulations to explore the detailed characteristics of the corona during these two periods, with particular emphasis on understanding the key factors that produce the differences in the observed properties of the solar corona. Research supported by NASA's Heliospheric Theory and Living With a Star Programs, and NSF/CISM.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMSH13C..05M
- Keywords:
-
- 7509 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Corona;
- 7511 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Coronal holes