:Product: Weekly Highlights and Forecasts
:Issued: 2002 Apr 02 2212 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Environment Center
# Product description and SEC contact on the Web
# http://www.sec.noaa.gov/weekly.html
#
#                Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
25 - 31 March 2002

Activity was low during 25 – 29 March, then increased to moderate
levels for the balance of the period. Region 9878 (N09, L = 040,
class/area Esi/170 on 26 March) was the most notable of a few
moderately complex sunspot groups that produced C-class flares
during 25 – 29 March (for flare specifics, please refer to the
Energetic Events or Optical Flares lists). It showed a delta
magnetic configuration for a few days, but began to slowly decay on
29 March. Activity increased to moderate levels on 30 March due to a
M3/1n flare at 30/1301 UTC from Region 9885 (N11, L = 320,
class/area Fki/600 on 31 March). It produced another low-level
M-class flare on 31 March. Region 9885 was active as it rotated into
view on 28 March, possibly the source for a C7 X-ray flare at
28/1800 UTC. It grew during 28 – 30 March to include the development
of a weak delta within its interior spots. However, it began to
gradually decay on 31 March with loss of its delta. Region 9887
(N01, L = 297, class/area Eai/240 on 31 March) produced isolated
subflares on 31 March as it began to grow. Currently, it is moderate
in size and magnetic complexity.

Solar wind data were available from NASA Advanced Composition
Explorer (ACE) spacecraft for most of the summary period. The last
of the CME passages associated with flare activity in old Region
9866 (S09, L = 191) occurred on 25 March. This relatively weak
passage began at around 25/0030 UTC accompanied by increased solar
wind velocities (peaks to 490 km/sec), minor increases in
temperature, density, and total IMF field intensity; and mostly
northward IMF Bz. A high-speed stream associated with a
positive-polarity coronal hole was detected on 26 - 27 March. High
speeds (peaks to 610 km/sec) and low proton densities occurred
during this stream, which subsided early on 27 March. Another
high-speed stream occurred during 30 – 31 March associated with low
densities and velocities in the 600 – 800 km/sec range. This stream
continued as the period ended.

There were no proton events at geo-synchronous orbit.

The greater than 2 MeV electron flux at geo-synchronous orbit was at
normal levels for most of the period.

Quiet to unsettled conditions prevailed until late on 29 March. A
sudden impulse occurred at 29/2237 UTC (31 nT, as measured by the
Boulder USGS magnetometer), followed by an increase to unsettled to
active levels for the remainder of the period.

Forecast of Solar and Geomagnetic Activity
03 - 29 April 2002

Solar activity is expected to be at low to moderate levels. Isolated,
low-level M-class flares are likely during the period.

The greater than 2 MeV electron flux may reach high levels during 03
– 05 April. Otherwise, normal to moderate levels are expected during
the period.

There will be a slight chance for a proton event during 10 – 17
April.

Active conditions are possible during 25 – 27 April due to recurrent
coronal hole effects. Quiet to unsettled conditions are expected
during the remainder of the period.


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