Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 05 Sep 2005

By SpaceRef Editor
September 6, 2005
Filed under , ,

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

Updated 2005 Sep 05 2204 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 248 Issued at 2200Z on 05 Sep 2005

IA. Analysis of Solar Active Regions and Activity from 04/2100Z
to 05/2100Z: Solar activity was low. A long duration C2 flare and
Type IV radio sweep occurred at 05/1041Z. A large and fast CME (2000
km/s) observed off the southeast limb, was also associated with this
event. The likely source of this flare was old active Region 798
(S09, L=217), which is due to rotate onto the visible disk on 07
Sep. Old Region 798 produced a proton flare during the latter stages
of its last transit across the visible disk (22-24 Aug), and was
responsible for a severe geomagnetic storm. Region 805 (S11W44), the
only region with sunspots on the visible disk, was quiet and stable.

IB. Solar Activity Forecast: Solar activity is expected to be low
on 06 Sep, but is expected to increase to at least moderate levels
on 07 and 08 Sep as old active Region 798 rotates onto the visible

IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z:
The geomagnetic field was quiet to active. Solar wind was elevated,
but declined from 650 km/s to near 450 km/s by the end the period.
The greater the 2 MeV electron flux at geosynchronous orbit was at
high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled with isolated active periods. The
large CME observed off the southeast limb this period is not
expected to be geoeffective.

III. Event Probabilities 06 Sep-08 Sep

  • Class M 10/25/35
  • Class X 01/05/10
  • Proton 01/05/05
  • PCAF Green

IV. Penticton 10.7 cm Flux

  • Observed 05 Sep 075
  • Predicted 06 Sep-08 Sep 080/090/100
  • 90 Day Mean 05 Sep 092

V. Geomagnetic A Indices

  • Observed Afr/Ap 04 Sep 018/026
  • Estimated Afr/Ap 05 Sep 015/015
  • Predicted Afr/Ap 06 Sep-08 Sep 010/010-005/005-005/005

VI. Geomagnetic Activity Probabilities 06 Sep-08 Sep

A. Middle Latitudes

  • Active 20/15/15
  • Minor storm 10/05/05
  • Major-severe storm 01/01/01

B. High Latitudes

  • Active 25/20/20
  • Minor storm 15/10/10
  • Major-severe storm 05/01/01

SpaceRef staff editor.