Improvement of Space Weather Forecasting in Solar Cycle 24

Abstract:

Solar Cycle 24 has not produced extreme space weather events at Earth
comparable to the Halloween 2003 events. However, there have been a
number of geomagnetic storms more intense than Dst of 100 nT as well
as several major solar energetic particle (SEP) events at Earth.
Before predicting geomagnetic storms and radiation storms well in
advance, it is necessary to make a firm link of solar activity,
notably coronal mass ejections (CMEs), with interplanetary CMEs
(ICMEs) and shock waves. This cycle has benefitted from the Solar
Dynamics Observatory that provides uninterrupted and high-quality
full-disk images at Earth, and the Solar Terrestrial Relations
Observatory that has observed CMEs away from the Sun-Earth line and
unambiguously isolated those that were directed toward Earth. This
presentation aims at evaluating how these observations have refined
our understanding of the origins of ICMEs and helped models reproduce
the arrival times of the disturbances and the occurrence and magnitude
of SEP events. We also discuss what may be critically missing and yet
essential for achieving useful predictions in the future. A review is
given as to how the forecasts on the basis of solar and near-Sun
observations have fared against the actual ICMEs and shocks, and how
many of the latter have not been properly handled because of no
obvious CMEs. A similar attempt is made for the occurrence and
magnitude of SEP events. It is important to critically analyze the
inadequate forecasts (or just expectations) in terms of uncertainties
from observations and modeling.