Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 15 Jan 2005

By SpaceRef Editor

January 15, 2005

Filed under Space Weather Prediction Center (NOAA), Space Weather Solar-Geophysical Activity, US

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2005 Jan 15 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 015 Issued at 2200Z on 15 Jan 2005

IA. Analysis of Solar Active Regions and Activity from 14/2100Z
to 15/2100Z: Solar activity was at high levels. Large Region 720
(N13W03) produced three major flares this period, beginning with an
X1/1b flare at 15/0043Z. There was no CME associated with this
X-class flare. An impulsive M8 flare was observed at 15/0431Z, and
at 15/0638Z, the region produced the most significant event of the
period, a long duration M8 flare. This event had associated intense
radio emission including a 160,000 sfu burst on 410 MHz and moderate
to strong centimetric bursts including a 3000 sfu Tenflare. Type II
(1300 km/s) and Type IV radio sweeps were also observed, and the
energetic protons (>10 MeV) began to rise soon after the flare
maximum. SOHO/LASCO imagery revealed a fast full halo coronal mass
ejection. Region 720 is a large and magnetically complex sunspot
group with white light area coverage exceeding 1600 millionths.
Strong shear along an extended east-west inversion line in this
region was the focal point for the major flare activity. Region 718
(S07W21) produced an M3 flare at 15/1423Z with an associated 420 sfu
Tenflare and CME off the southwest limb.

IB. Solar Activity Forecast: Solar activity is expected to continue
at moderate to high levels. Region 720 has potential for M and
X-class flares. An isolated M-class flare is also possible from
Region 718.

IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z:
The geomagnetic field ranged from unsettled to minor storm periods
with isolated major storm levels at high latitudes. A gradual rise
in the solar wind speed began early in the period, rising to a peak
speed near 700 km/s, before gradually declining to near 550 km/s.
The IMF Bz was predominantly southward during the first half of the
period, which accounted for the most disturbed conditions. A greater
than 10 MeV proton enhancement began soon after today’s long
duration M8 flare. The protons did not exceed the 10 pfu threshold,
and remain elevated. The greater than 2 MeV electron flux at
geosynchronous orbit was at high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to range from quiet to severe storm levels. Solar wind
remains elevated at near 500 Km/s which may produce isolated active
periods early on 16 January. A CME associated with today’s long
duration M8 flare is expected to impact the geomagnetic field late
on 16 January into 17 January. Major to severe storm periods are
possible during this disturbance. Barring another Earth-directed
CME, the geomagnetic field will likely return to unsettled levels
with isolated active periods on 18 January.

III. Event Probabilities 16 Jan-18 Jan