[Ips-dsgr] IPS Daily Report - 30 May 03
rwc
rwc at ips.gov.au
Sat May 31 08:35:07 EST 2003
SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 30/2330Z MAY 2003 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 30 MAY AND FORECAST FOR 31 MAY - 02 JUNE
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: ** YELLOW **
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1A. SOLAR SUMMARY
Activity 30 May: Low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 30 May: 117/69
1B. SOLAR FORECAST
31 May 01 Jun 02 Jun
Activity Moderate Moderate Moderate
Fadeouts Possible Possible Possible
10.7cm/SSN 115/66 110/60 105/54
COMMENT: A shock like feature was observed in the solar wind
at around 1530 UT. Solar wind speed increased from 500 to 700km/sec
around this time but did not change fast enough for it
to be called a shock. Also, no increase in solar wind density
was observed. However, increases in total interplanetary magnetic
and solar wind temperature were observed. The north-south component
of the interplanetary magnetic field (Bz) fluctuated southward
by up to 20nT around the time of the quasi-shock but quickly
returned to neutral/slightly northward reducing geomagnetic effects
(the Bz "storm switch" was "off"). Also, the large coronal hole
visible in SOHO imagery is now at solar central meridian, high
speed wind stream entry expected 02 Jun. Extended period of elevated
solar wind speed conditions expected 02 - 10 Jun. The solar region
that has been producing the X class events is nearing the western
solar limb and is showing signs of decay, solar forecast decreased
to moderate. There is an outside chance for another shock arrival
in the next 24 hours. ACE EPAM data (shock precursor) showed
a rise and fall as the last shock passed. The most recent data
shows a slight rise, but it is unclear if this is a trend start
or just a blip. A weak solar proton event which followed the
X class flare activity has ended (began 0155UT 29 May, ended
0150UT 30 May).
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 30 May: Quiet to Minor Storm
Estimated Indices 30 May : A K
Australian Region 30 5543 3532
Darwin 32 5543 453-
Townsville 30 5533 453-
Learmonth 32 5543 354-
Canberra 30 6433 353-
Hobart 27 6433 343-
Casey(Ant) 24 4543 3432
Observed Regional daily pc3 Indices 30 MAY :
Townsville 112 (Major storm)
Learmonth 153 (Severe storm)
Canberra NA
Hobart NA
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 30 May : A
Fredericksburg 35
Planetary 60
Observed AFr/Ap Indices 29 May : A K
Fredericksburg 59
Planetary 89 5443 6788
2B. MAGNETIC FORECAST
Date Ap Conditions
31 May 25 Unsettled to active, chance storm due to possibility
of another shock arrival.
01 Jun 13 Unsettled
02 Jun 20 Active
COMMENT: IPS Geomagnetic Warning 20 was issued on 29 May and
is current for interval 30-31 May. It appears that the mass ejection
from the most recent X class event again arrived "early", with
a weak impulse of 23nT observed in the geomagnetic field at 1625UT
30 May. Post shock arrival activity was reduced due to the north-south
component of the IMF remaining predominately northward postshock.
Due to perceived ambiguity in solar mass ejections and shock
arrivals, there is an outside chance for another shock arrival
/impulse in the next 24 hours. The strong disturbance originally
forecast for today has been reduced due to the lack of activity
post shock arrival. In addition coronal hole high speed wind
stream effects expected from 02 Jun. Recurrence suggests that
an extended period of elevated geomagnetic activity can be expected
until around 10 Jun.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
30 May Fair-normal Poor-fair Poor
PCA Event : Began at 0155UT 29/05, Ended at 0150UT 30/05
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
31 May Normal Normal-Fair Fair
01 Jun Normal Normal Normal-Fair
02 Jun Normal Normal-Fair Fair
COMMENT: HF conditions very degraded yesterday. Improving HF conditions
now expected for today due to weak activity associated with the
arrival of last CME.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
30 May 24
Observed Australian Regional MUFs
Equatorial PNG Region:
Depressed by 15% during local day,
Near predicted monthly values during local night.
Northern Australian Region:
Near predicted monthly values during local day,
Depressed by 15% during local night.
Southern Australian and New Zealand Region:
Depressed by 30% during local day,
Depressed by 25% during local night.
Depressed by 25% after local dawn.
Antarctic Region (Casey/Scott Base):
Absorption observed.
Predicted Monthly T index for May: 72
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
31 May 75 near predicted monthly values (North Aus)
31 May 45 depressed 10 to 20% (South Aus)
01 Jun 60 depressed 10 to 20%/near predicted monthly values
02 Jun 75 Near predicted monthly values
COMMENT: Depressed conditions observed in southern Aus/NZ region
yesterday. Northern Aus region remained mostly near normal. Ionospheric
conditions now expected to be better than originally forecast
for 31 May due to lack of geomagnetic activity following recent
solar mass ejection arrival overnight. Depressions of 10-20%
likely to be experienced for southern region sites after local dawn
this morning. Northern region MUFs expected to remain near predicted
monthly values.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 29 May
Daily Proton Fluence >1 MeV: 2.4E+08
Daily Proton Fluence >10 MeV: 2.9E+06
Daily Electron Fluence >2 MeV: 4.80E+07 (normal)
X-ray background: B3.0
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
ACE Satellite Solar Wind Day Averaged Data for 29 May
Speed: 670 km/sec Density: 5.3 p/cc Temp: 81700 K Bz: -2 nT
(Courtesy Space Environment Center, Boulder USA)
ACE data can be incorrect during strong proton events.
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