[Ips-dsgr] IPS Daily Report - 18 August 02

rwc rwc at ips.gov.au
Mon Aug 19 09:15:50 EST 2002


SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 18/2330Z AUGUST 2002 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 18 AUGUST AND FORECAST FOR 19 AUGUST - 21 AUGUST
STATUS INDICATORS SOL:** RED **   MAG:** YELLOW **     ION: GREEN
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 18 Aug:  Moderate

Flares    Max     Fadeout    Freq.  Sectors
  M2.5    1005UT  possible   lower  European
  M2.1    1439UT  possible   lower  South American/
                                    Atlantic
  M2.4    2126UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Aug: 241/190


1B. SOLAR FORECAST
             19 Aug             20 Aug             21 Aug
Activity     Moderate to high   Moderate to high   Moderate to high
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   245/195            245/195            230/180
COMMENT: A strong shock was observed in the solar wind at 1809UT 
on 18 Aug. Shock arrived later than expected. Solar wind speed 
increased from 450 to nearly 600 km/sec. The north-south component 
of the interplanetary magnetic field (Bz) only fluctuated southward 
10nT post shock. Large solar region 69 produced the M2 events. 
The event at 2126UT was associated with a Type II radio-sweep 
(1000km/sec), observed on the Culgoora Spectrograph and Culgoora 
H-Alpha imagery showed that the flare was located in the southern 
portion of this large and magnetically complex region. A mass 
ejection is inferred from these data, however no Lasco imagery 
was available to confirm. Shock arrival window for this event 
is 03-14UT 21 Aug. Further M and X class flares expected. Region 
69 is now about 14 degrees west of the centre of the solar disk, 
and is in a good geoeffective location if further mass ejection 
events eventuate. Solar region 79 located in the south-east quadrant 
of the solar disk is showing growth. 
-----------------------------------------------------------
2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 18 Aug: Quiet to Minor Storm 

Estimated Indices 18 Aug :  A   K           
   Australian Region      14   2312 3254
      Townsville           9   2212 2244
      Learmonth            7   -311 ----
      Canberra             8   2201 2244
      Hobart               9   2211 3144
      Casey(Ant)          16   3322 3254
      Davis(Ant)          25   33-3 3364
    
Observed Regional daily pc3 Indices 18 AUG : 
      Townsville           0   (Quiet)
      Learmonth           NA
      Canberra            16   (Quiet)
      Hobart               6   (Quiet)

Estimated AFr/Ap Indices 18 Aug : A 
           Fredericksburg        15
           Planetary             20                         

Observed AFr/Ap Indices 17 Aug :  A   K
           Fredericksburg         8
           Planetary             13   2343 2233     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
19 Aug    18    Active, chance of minor storm periods local midnight. 
20 Aug    12    Unsettled to active 
21 Aug    20    Active 
COMMENT: IPS Geomagnetic Warning 29 was issued on 16 August and 
is current for interval 18-19 August. Storm activity was over-forecast. 
Storm activity now not expected, as Bz did not swing far southward 
post shock arrrival. There is a chance for isolated minor storm 
periods around local midnight tonight. A possible period of weak 
CME (assumed) induced activity is possible on 21 Aug. 
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
18 Aug      Normal         Normal-fair    Fair           
PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
19 Aug      Normal         Normal-Fair    Fair
20 Aug      Normal         Normal         Normal-Fair
21 Aug      Normal         Normal-Fair    Fair
COMMENT: Moderate degradation expected today and on day 3 of 
forecast period. Proton flux remains elevated but below event 
threshold, possibly increasing absorption on polar HF links. 
Further fadeouts can be expected on daylight HF circuits. 
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
18 Aug   148

Observed Australian Regional MUFs
   Equatorial PNG Region:
      Enhanced by 25-45% during local day,
      Enhanced by 90% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day,
      Enhanced by 25%.
   Southern Australian and New Zealand Region:
      Enhanced by 15% during local day,
      Enhanced by 40% during local night.
   Antarctic Region (Casey/Scott Base):
      Enhanced by 30% over the UT day.
      Some spread and absorption observed.


Predicted Monthly T index for August: 102

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
19 Aug   140    about 15% above predicted monthly values 
20 Aug   140    about 15% above predicted monthly values 
21 Aug   140    about 15% above predicted monthly values 
COMMENT: Strong degradation did not eventuate post CME shock 
arrival. Moderate degradation possible local night hours 
day 1 and 3 of forecast period. Fadeouts can be expected 
on daylight HF circuits. 
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 17 Aug
       Daily Proton Fluence >1 MeV:   7.7E+06
       Daily Proton Fluence >10 MeV:  2.4E+05
       Daily Electron Fluence >2 MeV: 5.30E+07 (normal)
       X-ray background: C1.9
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.

ACE Satellite Solar Wind Day Averaged Data for 17 Aug
Speed: 473 km/sec  Density:    2.1 p/cc  Temp:    87200 K  Bz:  -4 nT

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