Persistent structures in near-surface flows from ring diagrams. Rachel Howe, University of Birmingham D. Baker, MSSL R. KomM , NSO R. Bogart, Stanford. Introduction. The Sun has flows at many scales, from global rotation to flows around active regions and down to granules.
Rachel Howe, University of Birmingham
D. Baker, MSSL
R. KomM, NSO
R. Bogart, Stanford
Note diagonal ‘grain’
Paired light-dark streaks suggest flows in or out of feature that drifts with differential rotation.
Slope up == faster than Carrington rate
Slope down == slower than C.R.
Shallower slope means more difference.
Not much to see here – quieter at minimum?
(Timescale of GONG)
On HMI timescale.
Note strong stripes at high latitudes.
Some grain visible here too.
Use cross-correlation analysis to translate stripes slope to rotation rate
Green – Magnetograms
Black – Global inversions
Red – HMI ring vx correlation
Blue – GONG ring vx correlation
Use inferred rotation rate at each latitude instead of Carrington rate.
‘l=1’ structure at high latitudes
HMI Line Core