Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Jun 2003

SDF Number 171 Issued at 2200Z on 20 Jun 2003

IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity increased to low levels today. Region
386 (S07E17) produced two low levels C-class flares today along with
several B-class flares. The northern portion of the penumbral field
appears to have undergone some rotation since yesterday while the
delta magnetic structure in the southern leading edge of group has
changed little during the period and remains intact. Region 387
(N18E36) was quiescent today although spot coverage and magnetic
complexity have both shown growth over the period. Region 389
(S12E14) was newly numbered today.

IB. Solar Activity Forecast: Solar activity is expected to range
from low to moderate levels. Region 386 remains capable of
producing an isolated major event.

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was at predominantly unsettled levels today as
effects from the western most recurrent coronal hole wanes. The
greater than 2 MeV electron flux at geosynchronous orbit reached
high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly unsettled levels. Active conditions
may exist especially at high latitudes beginning late on day two
with the return of a recurrent coronal hole high speed stream.

III. Event Probabilities 21 Jun-23 Jun

• Class M 40/40/40
• Class X 10/10/10
• Proton 10/10/10
• PCAF yellow

IV. Penticton 10.7 cm Flux

• Observed 20 Jun 117
• Predicted 21 Jun-23 Jun 115/115/120
• 90 Day Mean 20 Jun 125

V. Geomagnetic A Indices

• Observed Afr/Ap 19 Jun 016/018
• Estimated Afr/Ap 20 Jun 010/015
• Predicted Afr/Ap 21 Jun-23 Jun 010/015-012/015-012/020

VI. Geomagnetic Activity Probabilities 21 Jun-23 Jun

A. Middle Latitudes

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

B. High Latitudes

• Active 30/30/40
• Minor storm 15/15/20
• Major-severe storm 05/05/05

PLAIN

K-Indices:

On 16 June, it was determined that a scaling problem exists with the Boulder magnetometer instrument. While this problem, and its fix are being investigated the primary instrument for Boulder K-indices has been switched to the Boulder USGS (via Domsat) magnetometer, effective 1500 UTC on 16 June.

GOES Protons:

To ensure continued operational monitoring of important energetic particle data, it is necessary to reassign primary/secondary designations for the GOES Space Environment Monitor (SEM) detectors. GOES 11 (113W) is now the primary satellite for protons. GOES 12 will continue as the primary satellite for magnetometer, X-ray, and electron measurements. GOES 10 (135W) will be the secondary satellite for all SEM sensors – magnetometer, X-ray, and energetic particles. Because of the degraded state of the proton data on GOES-10, its designation as the secondary source for proton data is a short-term solution. More permanent solutions have been identified and are being evaluated. Users will be notified when we define and schedule a permanent fix. Further details can be found at http://www.sec.noaa.gov/GOES.html.