| The availability of
full-disk, high-resolution Ha images from Big Bear
Solar Observatory (USA), Kanzelhöhe Solar Observatory (Austria), and Yunnan
Astronomical Observatory (China) allows for the continual monitoring of solar
activity with unprecedented spatial and temporal resolution. Typically, this
Global Ha Network (GHN) provides almost
uninterrupted Ha images with a cadence of 1 min and
an image scale of 1'' per pixel.
Every hour, GHN images are transferred to the web-based BBSO
Active Region Monitor (ARM; www.bbso.njit.edu/arm), which includes the most
recent EUV, continuum, and magnetogram data from the Solar and Heliospheric
Observatory, together with magnetograms from the Global Oscillation Network
Group. ARM also includes a variety of active region properties from the
National Oceanic and Atmospheric Administration’s Space Environment Center,
such as up-to-date active region positions, GOES 5-min X-ray data, and flare
identification. Stokes I, V, Q, and U images are available from the recently
operational BBSO Digital Vector Magnetograph and the Vector Magnetograph at the
Huairou Solar Observing Station of Beijing Observatory. Vector magnetograms
provide complete information on the photospheric magnetic field, and allow for
magnetic flux gradients, electric currents, and shear forces to be calculated:
these measurements are extremely sensitive to conditions resulting in flaring
activity. Furthermore, we have developed a Flare Prediction System which
estimates the probability for each region to produce C-, M-, or X-class flares
based on nearly eight years of NOAA data from cycle 22. This, in addition to
BBSO’s daily solar activity reports, has proven a useful resource for
activity forecasting.
Key words. Solar physics, astronomy
and astrophysics (flares and mass ejections; instruments and techniques;
photosphere and chromosphere) |