[Ips-dsgr] IPS Daily Report - 17 April 01

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SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 17/2330Z APRIL 2001 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 17 APRIL AND FORECAST FOR 18 APRIL - 20 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: ** YELLOW **
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1A. SOLAR SUMMARY
Activity 17 Apr:  Moderate

Flares    Max     Fadeout    Freq.  Sectors
  M1.3    2203UT  possible   lower  West Pacific

Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Apr: 126/79

GOES satellite data for 16 Apr
       Daily Proton Fluence >1 MeV:   9.8E+07
       Daily Proton Fluence >10 MeV:  1.8E+07
       Daily Electron Fluence >2 MeV: 3.00E+08 (moderate)
       X-ray background: B6.9
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.

1B. SOLAR FORECAST
             18 Apr             19 Apr             20 Apr
Activity     Moderate           Moderate           Moderate
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   135/89             145/99             155/109

COMMENT: A decline in solar activity may be experienced. However, 
a large previously flaring region (sec 9393) is due back around 
18 Apr. This region showed decay on leaving the solar disk on 
its previous transit. If this region does return, (there is a 
possible brightening on the northeast limb in Yohkoh softxray 
imagery), or represented an active solar longitude, increased 
flare activity may be experienced after this date. A shock is 
expected in the solar wind today from recent X14 flare. ACE EPAM 
data showed increasing proton flux, a possible precursor signature 
to shock arrival. 
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 17 Apr: Quiet to Unsettled 

Estimated Indices 17 Apr :  A   K           
   Australian Region        5   1212 1222
      Darwin                5   1212 122-
      Townsville            5   1212 1222
      Learmonth             8   2222 2322
      Canberra              5   1212 1222
      Hobart                5   1212 1222
    
Observed Regional daily pc3 Indices 17 APR : 
      Darwin                0   (Quiet)
      Townsville            0   (Quiet)
      Learmonth             0   (Quiet)
      Canberra              4   (Quiet)
      Hobart               14   (Quiet)

Estimated AFr/Ap Indices 17 Apr : A 
           Fredericksburg         8
           Planetary             15                         

Observed AFr/Ap Indices 16 Apr :  A   K
           Fredericksburg         7
           Planetary              7   3211 2322     
2B. MAGNETIC FORECAST 
Date      Ap    Conditions
18 Apr    30    Active to minor storm 
19 Apr    18    active 
20 Apr    13    Quiet to Active 
COMMENT: IPS Geomagnetic Warning 15 was issued on 16 April and 
is current for interval 18-19 April. Moderate geomagnetic activity 
expected on 18 April due to recent X14 flare, and coronal hole 
effects. 
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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
17 Apr      Normal         Fair-normal    Poor-fair      
PCA Event : Began at 1405UT 15/04, Ended at 1805UT 17/04
3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
18 Apr      Fair           Fair           Fair-Poor
19 Apr      Normal         Normal-Fair    Fair
20 Apr      Normal         Normal         Normal-Fair
COMMENT: High latitude HF communications improved as proton event 
ended. High latitude HF communication expected to return to degraded 
conditions due to anticipated geomagnetic activity from X14 flare 
and recurrent factors. 
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date   T index
17 Apr   126

Observed Australian Regional MUFs
   Equatorial PNG Region:
      Near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian and New Zealand Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Scott Base):
      Near predicted monthly values over the UT day.


Predicted Monthly T index for April: 120

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
18 Apr    95    near predicted monthly values/depressed 10 to 
                20% 
19 Apr    85    depressed 10 to 15%/near predicted monthly values 
20 Apr   120    Near predicted monthly values 
COMMENT: IPS HF Communications Warning 26 was issued on 16 April 
and is current for interval 18-19 April. Degraded HF conditions 
expected late on 18 April due to anticipated geomagnetic activity 
from X14 flare. Effects are expected to be confined to mid to 
high latitudes (southern Aus/NZ region). 

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