AGU Fall 2011 Meeting
Abstract SH54A-04
| ABSTRACT FINAL ID: SH54A-04; |
| TITLE: Solar surface circulation velocities and magnetic fields from cycle 22 to early cycle 24 |
| SESSION TYPE: Oral |
| SESSION TITLE: SH54A. Forecasting and Data Assimilation in Solar and Heliospheric Physics II |
| AUTHORS (FIRST NAME, LAST NAME): Roger K Ulrich1 |
| INSTITUTIONS (ALL): 1. Physics and Astronomy, UCLA, Los Angeles, CA, United States. |
| Title of Team: |
| ABSTRACT BODY: Solar surface velocities and magnetic fields have been recorded at the 150-foot tower telescope at the Mt. Wilson Observatory (MWO) since 1967. Three quantities from the MWO analysis are discussed: torsional oscillations, meridional flow velocities and sectoral magnetic fields. The MWO data show that leading to the cycle 23/24 minimum the dipole field was half that for the previous cycle. The torsional oscillation strength has been similar to previous cycles up to the current phase of cycle 24 while the meridional circulation speed has declined over most of the solar surface to values half that previously found. Changes in the large-scale circulation velocity and magnetic fields will impact the future development of the solar cycle and should be incorporated into dynamo models. http://obs.astro.ucla.edu/intro.html |
| KEYWORDS: [7536] SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY / Solar activity cycle, [7524] SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY / Magnetic fields, [7544] SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY / Stellar interiors and dynamo theory. |