:Product: Weekly Highlights and Forecasts
:Issued: 2002 Feb 26 2212 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Environment Center
# For a descriptive text, or to contact SEC, refer to the Web page
# http://www.sec.noaa.gov/weekly.html
#
#                Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
18 - 24 February 2002

Solar activity ranged from low to high levels. Activity was at low to
moderate levels during 18 – 19 February with an isolated M1/Sf
long-duration flare and some C-class flares from Region 9830 (S19, L
= 134, class/area Fkc/610 on 19 February). Region 9830 was in a
gradual growth phase during 16 – 19 February and developed multiple
delta magnetic configurations within its leader spots. It began to
gradually decay on 20 February, but remained complex as a (weakened)
magnetic delta persisted within its leader spots. Activity increased
to high levels on 20 February due to an M5/1n flare at 20/0612 UTC
from Region 9825 (N14, L = 206, class/area Fkc/500 on 14 February),
which was crossing the west limb at the time. Region 9825 “awoke”
with three M-class flares on 20 February (including the
aforementioned M5/1n) following several days of gradual decay and
inactivity. The sudden increase in flare activity coincided with the
rapid emergence of opposite-polarity flux northwest of its leader
spots. Activity dropped to moderate levels on 22 February with
multiple low-level M-class flares from Region 9825 as it rotated out
of view. Activity remained at moderate levels on 22 February with an
M2/2n flare from Region 9830, which continued to gradually decay.
Activity dropped to low levels during the last two days of the
period due to occasional C-class flares.

Solar wind data were available from the NASA Advanced Compositions
Explorer (ACE) spacecraft for most of the period. A relatively weak
recurrent high-speed stream was observed during 21 February. Solar
wind speeds increased early on 21 February with peak velocities in
the 490 to 520 km/sec range. Velocities gradually decreased during
the later half of the day as the high-speed stream subsided. This
stream was likely associated with a small, negative-polarity coronal
hole.

A brief greater than 10 MeV proton event occurred at geosynchronous
orbit on 20 February following the M5/1n flare at 20/0612 UTC from
Region 9825. The event began at 20/0700 UTC, reached a peak of 13.5
PFU at 20/0755 UTC, and ended at 20/0800 UTC.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal levels.

Geomagnetic field activity was at quiet to unsettled levels
throughout the period.

Forecast of Solar and Geomagnetic Activity
27 February - 25 March 2002

Activity is expected to be at low to moderate levels. Isolated
low-level M-class flares are expected during the period. There will
also be an increased chance for isolated major flare activity
beginning on 07 March with the return of old Region 9825.

The greater than 2MeV electron flux may reach high levels during 06 –
08 March. Otherwise, normal to moderate levels will be the norm.

There will be a slight chance for a proton event during the latter
half of the period.

Active periods are possible during 04 – 06 March due to recurrent
coronal hole effects. Otherwise, quiet to unsettled conditions will
be the norm.


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