[Ips-dsgr] IPS Daily Report - 24 May 01

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SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 24/2330Z MAY 2001 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 24 MAY AND FORECAST FOR 25 MAY - 27 MAY
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: **YELLOW**
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1A. SOLAR SUMMARY
Activity 24 May:  Moderate

Flares    Max     Fadeout    Freq.  Sectors
 M1/1N    1944UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 24 May: 170/124

GOES satellite data for 23 May
       Daily Proton Fluence >1 MeV:   2.9E+05
       Daily Proton Fluence >10 MeV:  1.5E+04
       Daily Electron Fluence >2 MeV: 9.10E+06 (normal)
       X-ray background: B6.0
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
1B. SOLAR FORECAST
             25 May             26 May             27 May
Activity     Low to moderate    Moderate           Moderate
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   165/119            170/124            170/124
COMMENT: Solar wind speed remained moderately elevated (due to 
coronal hole) throughout the UT day. A type II radio sweep and 
mass ejection were reported with the M1 event. The M1 flare was 
from solar region 9468 just east of the centre of the solar disk. 
Available event data suggests a shock arrival window of 10-24UT 
on 27 May. Also, another mass ejection was observed behind the 
north-east limb of the sun. This may indicate the possible return 
of solar region 9445. This region on its previous rotation was 
magnetically complex, and of moderate size, showing decay as 
it rotated off disk. It produced only 1 M class event on during 
disk transit. Further M class activity is expected. 
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 24 May: Quiet to Unsettled 

Estimated Indices 24 May :  A   K           
   Australian Region       5   2311 1111
      Darwin               5   2311 1111
      Townsville           3   22-0 1011
      Learmonth            7   2312 2212
      Canberra             4   2301 1000
      Hobart               3   2212 1000
    
Observed Regional daily pc3 Indices 24 MAY : 
      Darwin              16   (Quiet)
      Townsville          64   (Active)
      Learmonth            0   (Quiet)
      Canberra            23   (Quiet to unsettled)
      Hobart              28   (Quiet to unsettled)
Estimated AFr/Ap Indices 24 May : A 
           Fredericksburg         8
           Planetary             10                         

Observed AFr/Ap Indices 23 May :  A   K
           Fredericksburg         8
           Planetary             11   3222 3433     
2B. MAGNETIC FORECAST 
Date      Ap    Conditions
25 May    15    Unsettled to Active 
26 May    12    Unsettled 
27 May    20    Initially unsettled, active to minor storm conditions 
                second half UT day. 
COMMENT: Active periods expected local night hours next 24 hours 
due to coronal hole effects. Geomagnetic activity is then expected 
to decline, on 26 May, before increasing during second half of 
UT day on 27 May due to recent M1/cme event. Moderately disturbed 
conditions are then expected. 
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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
24 May      Normal         Normal         Fair-normal    
PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
25 May      Normal         Normal-fair    Fair          
26 May      Normal         Normal         Normal-fair   
27 May      Normal         Normal-fair    Fair          
COMMENT: Mild degradation in HF comms quality expected at mid 
to high latitudes, 25 and 27 May. 
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date   T index
24 May   121

Observed Australian Regional MUFs
   Equatorial PNG Region:
      Near predicted monthly values during local day,
      Enhanced by 15% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day,
      Depressed by 20% during local night.
   Southern Australian and New Zealand Region:
      Mostly near predicted monthly values,
   Antarctic Region (Casey/Scott Base):
      Near predicted monthly values over the UT day.
      Spread F observed.

Predicted Monthly T index for May: 117
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
25 May   110    depressed 10 to 15%/near predicted monthly values 
26 May   115    Near predicted monthly values 
27 May   105    near predicted monthly values/depressed 10 to 
                15% 
COMMENT: Expected coronal hole induced activity may produce mild 
ionospheric depressions 24/25 May. Further degradation possible 
27/28 May, mid to high latitudes only. 

IPS Radio and Space Services      | email: asfc at ips.gov.au
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