[SECC] Propagation

[Hal Kennedy]

http://www.sec.noaa.gov/advisories/bulletins.html


SPACE WEATHER ADVISORY BULLETIN #03- 2
2003 October 22
0011 UTC

Two very dynamic centers of activity have emerged on the sun. NOAA Region
484 developed rapidly over the past three days and is now one of the largest
sunspot clusters to emerge during Solar Cycle 23, approximately 10 times
larger than Earth. This region, which is nearing the center of the solar
disk, already produced a major flare (category R3 Radio Blackout on the NOAA
Space Weather Scales) on 19 October at 1650 UTC. The region continues to
grow, and additional substantial flare activity is likely.
A second intense active region is rotating around the southeast limb of the
sun. Though the sunspot group is not yet visible, two powerful eruptions
occurred on 21 October as seen from the LASCO instrument on the SOHO
spacecraft. These eruptions may herald the arrival of a volatile active
center with the potential to impact various Earth systems.

Further major eruptions are possible from these active regions as they
rotate across the face of the sun over the next two weeks. Agencies impacted
by solar flare radio blackouts, geomagnetic storms, and solar radiation
storms may experience disruptions over this two-week period. These include
satellite and other spacecraft operations, power systems, HF communications,
and navigation systems

N4GG