[Ips-dsgr] IPS Daily Report - 18 April 03

[rwc]

SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 18/2330Z APRIL 2003 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:GREEN   MAG:** YELLOW **     ION: GREEN
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1A. SOLAR SUMMARY
Activity 18 Apr:  Moderate

Flares    Max     Fadeout    Freq.  Sectors
  M1.1    1958UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Apr: 108/58


1B. SOLAR FORECAST
             19 Apr             20 Apr             21 Apr
Activity     Low                Low                Low
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   110/60             110/60             115/66
COMMENT: Background X-ray flux has increased from previous low 
levels as new active regions rotate onto the visible solar disk. 
An impulsive M1 level flare was observed in GOES X-ray imagery 
at 1950UT. The region of origin, AR 337, on the extreme east 
limb appears capable of further C to M class activity. Activity 
from this region is unlikely to be geoeffective at this stage 
due to its east limb location. 



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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 18 Apr: Quiet to Active 

Estimated Indices 18 Apr :  A   K           
   Australian Region      15   2324 4322
      Darwin              13   2323 4322
      Townsville          11   2323 3322
      Learmonth           15   2324 4322
      Canberra            15   2324 4322
      Hobart              15   2324 4322
      Casey(Ant)          15   3433 32--
    
Observed Regional daily pc3 Indices 18 APR : 
      Townsville           2   (Quiet)
      Learmonth           15   (Quiet)
      Canberra            57   (Unsettled)
      Hobart              44   (Unsettled)
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        18
           Planetary             19                         

Observed AFr/Ap Indices 17 Apr :  A   K
           Fredericksburg        20
           Planetary             30   3555 4533     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
19 Apr    18    active 
20 Apr    15    Unsettled to Active 
21 Apr    12    Unsettled 
COMMENT: Solar wind speed declined from 700 to 600 km/s over 
the UT day as the present coronal hole rotates past the west 
solar limb. The interplanetary magnetic field has continued to 
fluctuate moderately about neutral, with some extended periods 
of southward polarity. Isolated active periods were observed 
at all latitudes on the IPS magnetometer network, with an isolated 
minor storm period at high latitude. Geomagnetic conditions should 
continue to decline from active to unsettled over the next two 
days. 

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

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
19 Apr      Normal         Normal-Fair    Fair
20 Apr      Normal         Normal         Normal-Fair
21 Apr      Normal         Normal         Normal-Fair
COMMENT: Variable periods of absorption and disturbance observed 
throughout the UT day at mid to high latitudes in association 
with elevated geomagnetic activity. HF conditions should improve 
over the next rwo days. 
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
18 Apr    80

Observed Australian Regional MUFs
   Equatorial PNG Region:
      Near predicted monthly values during local day,
      Enhanced by 25% 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):
      Near predicted monthly values over the UT day.


Predicted Monthly T index for April:  77

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
19 Apr    90    Near predicted monthly values 
20 Apr   100    near predicted monthly values 
21 Apr   110    5 to 10% above predicted monthly values 
COMMENT: Mild ionospheric depressions due to absorption observed 
throughout the UT day NZ/S Ocean region. Extensive spread-F conditions 
observed Antarctic regions. Periods of spread-F and high absorption 
observed at high latitudes in response to coronal hole induced 
geomagnetic disturbance. Expect similar conditions today. Current 
solar coronal hole induced conditions should improve over the 
next two days. 
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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 17 Apr
       Daily Proton Fluence >1 MeV:   9.3E+06
       Daily Proton Fluence >10 MeV:  1.1E+04
       Daily Electron Fluence >2 MeV: 3.70E+08 (moderate)
       X-ray background: B1.5
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.

ACE Satellite Solar Wind Day Averaged Data for 17 Apr
Speed: 716 km/sec  Density:    2.1 p/cc  Temp:   237000 K  Bz:  -2 nT

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