Author(s): , , ,
Institution(s): 1. Stanford University
The Helioseismic and Magnetic Imager (HMI) on NASA’s Solar Dynamics Observatory (SDO) has continuously measured the vector magnetic field, intensity, and Doppler velocity in solar flares and over the entire solar disk since May 2010. The regular cadence of 45 seconds for line-of-sight and 12 minutes for vector measurements enables reliable investigations of photospheric conditions before, during, and after events both locally and globally. Active region indices can be tracked and conditions in the overlying corona can be modeled. A few examples show the utility of the data and demonstrate that some care must be exercised when the HMI data are used to investigate time variations.