"HMI & SDO: All the Sun, All of the Time"
Abstract: The Solar Dynamics Observatory was launched in February 2010
and has been observing the Sun continuously since that April. The three
SDO instruments provide a comprehensive view of the evolving
photosphere, corona, and interior. In particular the Helioseismic and
Magnetic Imager instrument measures the Doppler shift, Zeeman splitting,
and intensity of the Fe 6173 spectral line in the photosphere every 45s
with 1 arc-second resolution. The vector magnetic field is determined
every 12 minutes and can be used to track the evolution of features and
model the overlying atmosphere. AR 11158 in February produced the first
X-class flare of the solar cycle; vector data for this region are now
available. All of the SDO data are available within minutes of
observation and can be used for predictive purposes.