The Relationship Between Plasma Flow Doppler Velocities and Magnetic Field Parameters During the Emergence of Active Regions at the Solar Photospheric Level

Abstract

A statistical study has been carried out of the relationship between plasma flow Doppler velocities and magnetic field parameters during the emergence of active regions at the solar photospheric level with data acquired by the Michelson Doppler Imager (MDI) onboard the Solar and Heliospheric Observatory (SOHO). We have investigated 224 emerging active regions with different spatial scales and positions on the solar disc. The following relationships for the first hours of the emergence of active regions have been analysed: i) of peak negative Doppler velocities with the position of the emerging active regions on the solar disc; ii) of peak plasma upflow and downflow Doppler velocities with the magnetic flux growth rate and magnetic field strength for the active regions emerging near the solar disc centre (the vertical component of plasma flows); iii) of peak positive and negative Doppler velocities with the magnetic flux growth rate and magnetic field strength for the active regions emerging near the limb (the horizontal component of plasma flows); iv) of the magnetic flux growth rate with the density of emerging magnetic flux; v) of the Doppler velocities and magnetic field parameters for the first hours of the appearance of active regions with the total unsigned magnetic flux at the maximum of their development.

14 pages, 8 figures. The results of article were presented at the ESPM-13 (12-16 September 2011, Rhodes, Greece, Abstract Book p. 102-103, P.4.13, http://astro.academyofathens.gr/espm13/documents/ESPM13_abstract_programme_book.pdf)

References in corpus (7)

• Interpretation of Solar Magnetic Field Strength Observations
• Statistical Study on the Nature of Solar Flux Emergence
• Two-step Emergence of the Magnetic Flux Sheet from the Solar Convection Zone
• Dependence of the Magnetic Energy of Solar Active Regions on the Twist Intensity of the Initial Flux Tubes
• Detection of Gravitational Waves through Observations of a Group of Pulsars
• Center-limb dependence of photospheric velocities in regions of emerging magnetic fields on the Sun
• The Horizontal Component of Photospheric Plasma Flows During the Emergence of Active Regions on the Sun

Cited by in corpus (4)

• Extended statistical analysis of emerging solar active regions
• Photospheric Velocity Structures during the Emergence of Small Active Regions on the Sun
• Analysis of the flux growth rate in emerging active regions on the Sun
• The Horizontal Component of Photospheric Plasma Flows During the Emergence of Active Regions on the Sun