Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 09 Aug 2003

By SpaceRef Editor
August 9, 2003
Filed under , ,

SDF Number 221 Issued at 2200Z on 09 Aug 2003

IA. Analysis of Solar Active Regions and Activity from 08/2100Z
to 09/2100Z: Solar activity was very low. Region 424 (S18W28)
maintains moderate size and complexity, but activity this period was
limited to occasional intensity fluctuations in the plage field. New
Region 431 (S12E68) was numbered today. This new region is likely
the return of old Region 410 which produced multiple C-class flares
during its last transit across the visible disk. A considerable
degree of surging was observed, but limb proximity is still making
it too difficult to assess this region’s true complexity. Nothing
remarkable in the remaining active regions.

IB. Solar Activity Forecast: Solar activity is expected to be at
low levels. Regions 424 and 431 both have potential for C-class
activity. There is a slight chance for an M-class flare.

IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z:
The geomagnetic field was unsettled to active. The high speed solar
wind stream is subsiding as the large equatorial coronal hole
rotates out of a geoeffective position. Wind speed began the period
near 750 km/s, but has gradually declined to near 650 km/s. The
greater than 2 MeV electron flux at geosynchronous orbit was at high

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to range from quiet to major storm levels. Predominantly
quiet to unsettled levels with occasional active periods are
expected on days one and two as the current high speed solar wind
stream continues to weaken. Another recurrent equatorial coronal
hole will move into a geoeffective position by day three and produce
occasional minor to major storm periods.

III. Event Probabilities 10 Aug-12 Aug

  • Class M 30/30/30
  • Class X 05/05/05
  • Proton 01/01/01
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 09 Aug 130
  • Predicted 10 Aug-12 Aug 135/135/135
  • 90 Day Mean 09 Aug 125

V. Geomagnetic A Indices

  • Observed Afr/Ap 08 Aug 022/032
  • Estimated Afr/Ap 09 Aug 015/016
  • Predicted Afr/Ap 10 Aug-12 Aug 015/015-015/020-025/035

VI. Geomagnetic Activity Probabilities 10 Aug-12 Aug

A. Middle Latitudes

  • Active 30/30/40
  • Minor storm 10/10/20
  • Major-severe storm 01/01/10

B. High Latitudes

  • Active 40/45/50
  • Minor storm 20/25/35
  • Major-severe storm 05/05/15

SpaceRef staff editor.