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Flaring activity is closely associated with sheared magnetic fields.
The twisted magnetic field above sunspots are sites where solar flares are observed to occur.
One way to track solar activity is thus by observing sunspots.
1. The McIntosh classification of sunspot groups is a proxy for
-the total magnetic flux in the active region,
through the first McIntosh parameter (Z)
which is correlated to the separation of the two polarity regions
and the active region area,
and through the third McIntosh parameter (c) which describes the compactness of
the central spot.
-the magnetic field of the largest spot, through the second McIntosh parameter (p)
which is related to the size of the largest spot.
One way to predict the occurence of solar flares is thus to look at the
probabilities for the occurence of C-, M- and X-flares, based on
statistics of McIntosh classification.
Click on a Catania sunspot group
reported on the most recent solar map,
and look for history plots of these probabilities and
history plots of the area and number of spots in the group.
See for instance the history
plots for the latest Catania sunspot group
#2,
#19,
#80,
#85 or
#98.
2. You may also use the magnetic classification of
active regions as a proxy for the magnetic complexity. This is given (in red) for each NOAA region
reported on the solar map.
Look also at the recent magnetograms, such as
the SOHO MDI 6767Å magnetogram,
the CaII 8542Å magnetogram (Kitt Peak),
the FeI line magnetogram (Mt Wilson) or others available
here.
3. The recent flaring activity indicates which regions are effectively active.
The history plot of a Catania sunspot group gives a schematic of time history of flaring
since the group is observed on the disk (see examples above).
Look also at the recent X-ray flares observed on GOES, event lists and the current movie of
SOHO EIT FeXII 195Å.
Those are linked on the solar weather
page. You may also look at the differential EIT FeXII 195Å movie (GIF format; see
NRL page for other formats).
4. The level of flaring activity to expect depends strongly
on how the X-ray background level evolves.
Highly complex configurations may only produce
C-class flares if the background level is low, and vice-versa.
Check the X-ray background level on GOES.
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To predict the 10.7 cm radio flux (precisely at frequency 2800MHz, but 2695MHz is an alternative) is to find a balance
between different budgets:
1. Check first the
radio flux values provided
by 5 radio observatories (Learmonth, San Vito, Sag Hill, Penticton and Palehua) and reported
by SEC (in addition, you could check the latest report
from DRAO Canada, the
quiet sun radio flux measurements from Learmonth or the
near-real-time solar radio indices from Trieste).
2. Look at radio images from Nancay (164 & 327MHz)
and latest movies from Nobeyama (17GHz).
See on the East limb if returning regions are about to reappear and would
contribute to increase the 10.7 cm radio flux. On the West limb, see if regions are about to turn behind the solar disk,
contributing to a decrease of the 10.7 cm radio flux.
This budget is related to the number of spots on the disk,
but also on the limb and just behind. It is therefore useful not only to check the photospheric white light continuum
(such as the latest SOHO MDI continuum
or the latest Catania observation)
but also to watch out for expected returning regions and for those regions turning behind the West limb
(see the solar map).
3. Watch out also for coronal holes (see the latest SOHO EIT FeXV 284Å
& the Kitt Peak coronal holes map),
which can contribute to a decrease of the 10.7 cm radio flux, when
they extend on the solar disk.
4. Relying on the 27-day recurrence period, one can also adjust the predictions according to the trend observed 27 days ago.
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In some cases CMEs can be expected, for CMEs are generally associated
1. either with flares (long duration flares in particular).
Those CMEs move generally fast.
2. or quiescent prominence (filament) eruptions. Those CMEs are generally slower.
But so far, they are observed rather than predicted. However, before seeing them
on LASCO coronographs and determine their speed in the plane of the sky (see guidelines below),
one can suspect a CME has formed, especially after a long duration flare or a
"disparition brusque" of a quiescent prominence. Moreover they can cause
3. EIT dimmings (EIT wave): see the differential EIT FeXII 195Å movie.
4. Radio type II bursts: which then indicate the speed of the CME front
(see
the list of radio bursts
prepared by SEC
or/and the latest
Culgoora PRESTO message).
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