Space Weather Advisory Bulletin #02-2 23 Jul 2002
Official Space Weather Advisory issued by NOAA Space Environment Center
Boulder, Colorado, USA
SPACE WEATHER ADVISORY BULLETIN #02- 2
2002 July 23 at 12:00 p.m. MDT (2002 July 23 1800 UTC)
**** ( CORRECTED ) MAJOR SUNSPOT ACTITVITY ****
A major sunspot region has rotated onto the visible face of the sun.
This region, designated as Region 39 by NOAA Space Environment Center
forecasters, is believed to have been the source of three large coronal
mass ejections on the far side of the sun beginning on July 16. This
region will rotate across the visible side of the sun over the next two
weeks and is expected to produce more solar activity.
Since appearing on the visible side yesterday (July 22) this region has
already produced a major flare at 6:35 pm Mountain Daylight Time (MDT)
on July 22 (0035, July 23 UTC). Radio blackouts reached category R3
(Strong) on the NOAA space weather scales. In response to the major
flare, a geomagnetic storm is possible and is expected to begin between
8:00 pm MDT on July 23 and 8 am MDT on July 24 (0200 – 1400, July 24
UTC). The geomagnetic storm may reach category G2 (moderate) levels on
the NOAA space weather scales.
Category R3 radio blackouts result in widespread HF radio communication
outages on the dayside of the Earth and can also degrade low frequency
navigation signals. Category G2 geomagnetic storms can lead to minor
problems with electrical power systems, spacecraft operations,
communications systems, and some navigational systems. Aurora
Borealis / Australis (northern / southern lights) may be seen down into
the mid latitudes (New York, Madison, Boise, Vladivostok, Rome,
Tasmania, Wellington – NZ, Puerto Montt – Chile)
Data used to provide space weather services are contributed by NOAA,
USAF, NASA, NSF, USGS, the International Space Environment Services
and other observatories, universities, and institutions. For more
information, including email services, see SEC’s Space Weather
Advisories Web site http://sec.noaa.gov/advisories or (303) 497-5127.
The NOAA Public Affairs contact is Barbara McGehan at
Barbara.McGehan@noaa.gov or (303) 497-6288.
