Reconstruction of Velocities in Solar Active Regions

Reconstruction of Velocities in Solar Active
Ravindra Belur
Indian Institute of astrophysics, Koramangala, Bangalore, India
Measurements of magnetic field at different levels of solar atmosphere are becoming
more sophisticated and accurate. At the same time a
precise measurements of the magnetic footpoint velocity is required to understand the
energy flow and injection of
helicity into the corona. The line-of-sight plasma velocity can be obtained from the
Doppler measurements
of spectral line, while magnetic footpoint velocity is obtained from techniques such as
local correlation tracking (LCT)
and feature finding algorithms. Recently several other methods have been developed
based on the ideal induction equation.
In this talk, I will discuss the several methods developed to infer the 3-components of
velocities using vector
magnetic field measurements. The comparison of various integrated quantities
computed from the velocities obtained from these
methods will be described. I'll also discuss the recent results obtained based on several
apodizing window functions used in LCT and how they are applied to the simulated
data sets.