Solar cycle measurements of lifetimes of active and ephemeral region flux
Wednesday
Abstract details
id
Solar cycle measurements of lifetimes of active and ephemeral region flux
Date Submitted
2019-03-07 11:05:07
Eddie
Ross
University of Birmingham
Active Region Laboratories
Talk
Eddie Ross (University of Birmingham), William J. Chaplin (University of Birmingham), Steven J. Hale (University of Birmingham), Rachel Howe (University of Birmingham), Yvonne P. Elsworth (University of Birmingham) Guy R. Davies (University of Birmingham)
We use very high-cadence (sub-minute) observations of the solar mean magnetic field (SMMF), covering a period of more than 20 years, to constrain the lifetimes of active region (AR) flux and ephemeral region (ER) flux on the Sun.
The ARs give rise to a rotationally modulated signal in the SMMF observations, which manifests itself as Lorentzian-like peaks in the frequency domain, whose widths allow us to measure the lifetimes of AR flux. The ERs introduce a stochastic, red-noise-like signal in the SMMF, whose fall off in power with frequency gives an estimation of the lifetimes of ER flux. We examine the relative contributions of ARs and ERs to the SMMF and provide an investigation into the evolution of the lifetimes with the solar activity cycle over the observational period.
The data used were collected by the Birmingham Solar-Oscillations Network (BiSON) node in Sutherland, South Africa since 1992.
All attendees are expected to show respect and courtesy to other attendees and staff, and to adhere to the NAM Code of Conduct. To report harassment or violation of the code of conduct please click here.