[Ips-dsgr] IPS Daily Report - 24 April 03

rwc rwc at ips.gov.au
Fri Apr 25 09:56:05 EST 2003


SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 24/2330Z APRIL 2003 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 24 APRIL AND FORECAST FOR 25 APRIL - 27 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
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1A. SOLAR SUMMARY
Activity 24 Apr:  Moderate

Flares    Max     Fadeout    Freq.  Sectors
 M3/1N    1253UT  possible   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Apr: 128/81

1B. SOLAR FORECAST
             25 Apr             26 Apr             27 Apr
Activity     Moderate           Moderate           Moderate
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   130/84             135/89             135/89
COMMENT: Solar activity was moderate today. One M3 flare 
from region 338(N18W45), observed at 1253UT, was associated 
with a Type II, a Type IV and a weak partial halo CME. 
Region 339 has also been quite active today before crossing 
the limb. This region produced several C-class flares- the 
largest being a C8 flare at 1553UT. The solar wind speed 
was nearly steady at approximately 450 km/s during the first 
half of the UT day, but then showed a gradual increase to 
approximately 550 km/s by the end of the day. It is not 
clear if this strengthning in the solar wind speed could 
be related to the CME activity observed on 21 April. A 
coronal hole is also taking geo-effective position and may 
start to strengthen the solar wind stream on 26 or 27 April. 
The north-south component of the interplanetary magnetic 
field continued to show minor to mild fluctuations between 
the north and south directions almost the whole day. Region 
338 still holds potential for M-class activity. 

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 24 Apr: Mostly quiet to 
active with isolated minor storm periods. 

Estimated Indices 24 Apr :  A   K           
   Australian Region      17   2234 4433
      Darwin              14   2233 3433
      Townsville          16   2224 4433
      Learmonth           17   3233 3443
      Canberra            22   2234 4543
      Hobart              23   2235 4533
      Casey(Ant)          16   3343 3333
    
Observed Regional daily pc3 Indices 24 APR : 
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Canberra            63   (Active)
      Hobart              78   (Active)
Pc3 pulsations are high frequency (10-45 second period) variations 
of the Earths magnetic field. Daily pc3 indices are the daily sum 
of 20 minute pc3 indices for that station.

Estimated AFr/Ap Indices 24 Apr : A 
           Fredericksburg        20
           Planetary             23                         

Observed AFr/Ap Indices 23 Apr :  A   K
           Fredericksburg        13
           Planetary             18   2454 3333     

2B. MAGNETIC FORECAST 
Date      Ap    Conditions
25 Apr    18    Mostly unsettled to active. Isolated minor storm 
                periods possible. 
26 Apr    20    Mostly unsettled to active. Isolated minor storm 
                periods possible. 
27 Apr    22    Mostly unsettled to active. Minor storm periods 
                possible. 
COMMENT: IPS Geomagnetic Warning 13 was issued on 24 April 
and is current for interval 25-26 April. The geomagnetic 
activity remained enhanced upto active and isolated minor 
storm levels on 24 April. As no shock has been recorded 
but solar wind stream was strengthned, it is not clear if 
this enhancement could be related to the partial halo CME 
activity observed on 21 April, which was expected to raise 
the geomagnetic activity around this period. A possible 
glancing effect of the weak partial halo CME observed on 
23 April may keep the goemangnetic activity enhanced on 
25 and 26 April. An expected coronal hole solar wind stream 
may also start to show its effect on 26 or 27 April which 
may continue to keep the geomagnetic activity enhanced. 

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
24 Apr      Normal         Normal         Fair-poor      
PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
25 Apr      Normal         Normal-Fair    Fair
26 Apr      Normal         Normal-Fair    Fair
27 Apr      Normal         Normal-Fair    Fair
COMMENT: Mild depressions are possible at times over the next 
few days due to anticipated elevated geomagnetic activity. 
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY

Date   T index
24 Apr    81

Observed Australian Regional MUFs
   Equatorial PNG Region:
      Mostly near predicted monthly values,
      Enhanced by 35% after local dawn.
   Northern Australian Region:
      Mostly near predicted monthly values,
      Enhanced by 20% after local dawn.
   Southern Australian and New Zealand Region:
      Mostly near predicted monthly values,
      Depressed by 25% after local dawn.
   Antarctic Region (Casey/Scott Base):
      Near predicted monthly values over the UT day
      with periods of mild to moderate depressions
      and degradations.


Predicted Monthly T index for April:  77

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
25 Apr    85    depressed 5 to 10%/near predicted monthly values 
26 Apr    85    depressed 5 to 10%/near predicted monthly values 
27 Apr    82    Depressed 5-10%/ near predicted monthly values. 
COMMENT: IPS HF Communications Warning 29 was issued on 
24 April and is current for interval 25-26 April. Mild 
depressions are possible at times over the next few days 
due to anticipated elevated geomagnetic activity. 
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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 23 Apr
       Daily Proton Fluence >1 MeV:   1.2E+06
       Daily Proton Fluence >10 MeV:  2.5E+04
       Daily Electron Fluence >2 MeV: 1.90E+08 (moderate)
       X-ray background: B4.9
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.

ACE Satellite Solar Wind Day Averaged Data for 23 Apr
Speed: 500 km/sec  Density:    4.3 p/cc  Temp:   145000 K  Bz:   1 nT

(Courtesy Space Environment Center, Boulder USA)
ACE data can be incorrect during strong proton events.
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