January 2002
A recent "hydrogen alpha" color image of the full solar disk has a reddish orange cast. The circumference is an irregular fringe of red light. Flares may be visible as brighter regions, sunspots as darker regions, and there may be other features such as dark lines and filaments. You can read a description of recent and projected solar activity in Weekly Highlights and Forecasts, a report by the NOAA Space Environment Center. This report also covers geomagnetic activity.
A recent high resolution "hydrogen alpha" color image of the sun has a reddish orange cast. Flares may be visible as brighter regions, sunspots as darker regions, and there may be other features such as dark lines and filaments. You can read an analysis of solar active regions and projected solar activity in Report of Solar-Geophysical Activity, a report by the NOAA Space Environment Center and U.S. Air Force. As the title indicates, this report also covers geogmagnetic activity.
An icon reports X-Ray activity as NORMAL, ACTIVE, M CLASS FLARE, X CLASS FLARE!, or MEGA FLARE!. It is derived from the solar X-Ray flux. Stated in microwatts per square meter, less than 1 unit is NORMAL, 1 or more is ACTIVE, 10 or more is M CLASS FLARE, 100 or more is X CLASS FLARE!, and 2000 or more is MEGA FLARE!. This information (and some interesting speculation) is provided by n3kl.org (formerly Majestic.com). Similar data is available in the Geophysical Alert Message. Its original solar activity terminology roughly corresponds to X-Ray flux with B1 (under 1) reported as very low, C1 (1) or more as low, M1 (10) or more as moderate, M5 (50) or more as high, and X1 (100) or more as very high. It has been planned to replace this with radio blackout terminology in which less than M1 (10) will result in no comment, M1 (10) or more will be reported as a R1 radio blackout, M5 (50) or more as a R2 blackout, X1 (100) or more as a R3 blackout, X10 (1000) or more as a R4 blackout, and X20 (2000) or more as a R5 blackout. You can read the geophysical alert message explanation and some information about X-Ray Flare Class. This information is provided the NOAA Space Environment Center.
An icon reports geomagnetic activity as QUIET,
UNSETTLED, or
STORM!. It is
derived from the K-index, a 3-hour measurement of magnetic
activity. Less than K4 is QUIET, K4 is
UNSETTLED, and
K5 to K9 is STORM!. This
information (and some interesting speculation) is provided by
n3kl.org (formerly Majestic.com).
Similar data is available in the Geophysical Alert
Message. The K-index itself is reported. The report's original
geomagnetic field terminology roughly corresponds to the K-indices
from the past 24 hours: K0-K1 is quiet, K1-K3 is unsettled, K4 is
active, K5 is minor storm, K6 is moderate storm, K7 is strong
storm, K8 is severe storm, and K9 is extreme storm. It has been
planned to replace this with geomagnetic storm terminology in which
less than K5 will result in no comment, K5 will be reported as a G1
geomagnetic storm, K6 as a G2 storm, K7 as a G3 storm, K8 as a G4
storm, and K9 as a G5 storm. You can read the geophysical
alert message explanation, some information about the
a
index and A Index from which the older descriptions are
derived, and some information about the K
index. This information is provided by the NOAA Space Environment Center.