[Ips-dsgr] IPS Daily Report - 18 April 01

[rwc]

SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 18/2330Z APRIL 2001 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 18 APRIL AND FORECAST FOR 19 APRIL - 21 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: ** YELLOW **
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1A. SOLAR SUMMARY
Activity 18 Apr:  Moderate

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Apr: 132/86

GOES satellite data for 17 Apr
       Daily Proton Fluence >1 MeV:   3.9E+07
       Daily Proton Fluence >10 MeV:  1.6E+06
       Daily Electron Fluence >2 MeV: 2.80E+08 (moderate)
       X-ray background: B5.1
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.

1B. SOLAR FORECAST
             19 Apr             20 Apr             21 Apr
Activity     Low to moderate    Low to moderate    Low to moderate
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   135/89             145/99             155/109


A strong shock was observed in the solar wind at 0640UT on 18 Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 18 Apr: 
Major storm declining to unsettled. 

Estimated Indices 18 Apr :  A   K           
   Australian Region       25   5553 2213
      Darwin               29   5653 1214
      Townsville           29   5653 2113
      Learmonth            24   5552 1224
      Canberra             24   5552 2223
      Hobart               26   5463 2212
    
Observed Regional daily pc3 Indices 18 APR : 
      Darwin               39   (Quiet to unsettled)
      Townsville            8   (Quiet)
      Learmonth            38   (Quiet to unsettled)
      Canberra             48   (Unsettled)
      Hobart               81   (Minor storm)
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 18 Apr : A 
           Fredericksburg        28
           Planetary             50                         

Observed AFr/Ap Indices 17 Apr :  A   K
           Fredericksburg         4
           Planetary              7   2322 2322     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
19 Apr    18    active 
20 Apr    13    Quiet to Active 
21 Apr     8    Quiet 
COMMENT: IPS Geomagnetic Warning 15 was issued on 16 April and 
is current for interval 18-19 April. Geomagnetic activity occured 
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 
18 Apr      Normal         Normal         Poor           
PCA Event : 10Mev Proton/PCA Event Began 18 04 2001 0330UT and is 
in progress

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
19 Apr      Normal         Normal-Fair    Poor(PCA)
20 Apr      Normal         Normal         Normal-Fair
21 Apr      Normal         Normal         Normal-Fair

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date   T index
18 Apr   123

Observed Australian Regional MUFs
   Equatorial PNG Region:
      Near predicted monthly values during local day,
      Depressed by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian and New Zealand Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Scott Base):
      PCA over the UT day


Predicted Monthly T index for April: 120

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
19 Apr   120    near predicted monthly values 
20 Apr   120    near predicted monthly values 
21 Apr   128    near predicted monthly values 
COMMENT: IPS HF Communications Warning 26 was issued on 16 April 
and is current for interval 18-19 April. PCA event in progress. 

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