[Ips-dsgr] IPS Daily Report - 10 May 03
rwc
rwc at ips.gov.au
Sun May 11 08:37:15 EST 2003
SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 10/2330Z MAY 2003 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 10 MAY AND FORECAST FOR 11 MAY - 13 MAY
STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: ** YELLOW **
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1A. SOLAR SUMMARY
Activity 10 May: Low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 10 May: 93/38
1B. SOLAR FORECAST
11 May 12 May 13 May
Activity Low Low to moderate Low to moderate
Fadeouts None expected Possible Possible
10.7cm/SSN 95/41 95/41 95/41
COMMENT: The decline in solar wind speed eventually occurred
today with wind speed at the start of the UT day at 750km/sec
declining to around 500km/sec by time of issue of this report.
The north-south component of the interplanetary magnetic field
(IMF) was southward 5nT for the first half of the UT day. Southward
IMF are associated with periods of increased geomagnetic activity.
It appears that the Earth left the coronal hole high speed wind stream at
around 00UT 10 May with a solar sector boundary change visible
in ACE Phi angle data at this time. (The Phi angle shows the
orientation, toward/away, of the solar wind magnetic field in
the horizontal plane). Such boundary crossings, changes in solar
wind magnetic field orientation, are also statistically associated
with disturbed geomagnetic conditions. Solar wind speed is expected
to increasing again over next 24 hours due to anticipated entry
into wind stream from second arm of "U" shaped coronal hole.
Also, an increase in solar activity may occur in coming days
due to the possibility of the return of a previously flaring
solar region 338.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 10 May: Quiet to Minor Storm
Estimated Indices 10 May : A K
Australian Region 24 4554 2222
Darwin 20 4543 2232
Townsville 22 4553 2223
Learmonth 26 5553 2232
Canberra 32 4565 2221
Hobart 31 4565 1221
Casey(Ant) - ---- ----
Observed Regional daily pc3 Indices 10 MAY :
Townsville 8 (Quiet)
Learmonth 33 (Quiet to unsettled)
Canberra 65 (Active)
Hobart 83 (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 10 May : A
Fredericksburg 20
Planetary 42
Observed AFr/Ap Indices 09 May : A K
Fredericksburg 20
Planetary 29 4455 5333
2B. MAGNETIC FORECAST
Date Ap Conditions
11 May 13 Unsettled
12 May 22 Unsettled to active, with minor storm periods
possible.
13 May 20 Unsettled to active, with minor storm periods
possible.
COMMENT: IPS Geomagnetic Warning 17 was issued on 9 May and is
current for interval 10-12 May. geomagnetic activity continued
longer and stronger than expected for the first half of the UT
day, probably in association with southward IMF and high solar
wind speed. The geomagnetic field is expected to be unsettled
today, before returning to active-minor storm levels by 12 May
due to second arm of coronal hole high speed wind stream. Recurrence
suggests that unsettled to active conditions may extend until
22 May, due to frequency of croronal holes on the solar disk.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
10 May Normal Fair Poor-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
11 May Normal Fair-Normal Normal-Fair
12 May Normal Normal-Fair Fair
13 May Normal Fair-Normal Fair
COMMENT: Unexpected degraded conditions observed at mid to high
latitudes overnight. Depression possible after local dawn.
HF conditions expected to briefly improve later today, before
returning to degraded, due to anticipated activity induced
by second arm of coronal hole wind stream.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
10 May 63
Observed Australian Regional MUFs
Equatorial PNG Region:
Near predicted monthly values during local day,
Enhanced by 30% during local night.
Northern Australian Region:
Near predicted monthly values during local day,
Enhanced by 20% during local night.
Southern Australian and New Zealand Region:
15% depressed to near predicted monthly values,
Depressed by 15% after local dawn this morning.
Antarctic Region (Casey/Scott Base):
15% depressed. Spread F observed.
Predicted Monthly T index for May: 72
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
11 May 55 depressed 10 to 15% (southern Aus/NZ region)
11 May 70 near predicted monthly values (northern Aus region)
12 May 70 near predicted monthly values
13 May 60 depressed 10 to 15%/near predicted monthly values
COMMENT: Geomagnetic activity continued longer than expected.
Southern Aus/NZ region MUFs again depressed 15% yesterday, and
depressed MUFs in southern region observed after local dawn this
morning. Northern Aus region MUFs again appear unaffected. HF
conditions may briefly improve later today, before returning
degraded due to second arm of coronal hole high speed wind stream.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 09 May
Daily Proton Fluence >1 MeV: 2.0E+06
Daily Proton Fluence >10 MeV: 1.0E+04
Daily Electron Fluence >2 MeV: 3.20E+08 (moderate)
X-ray background: B2.7
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
ACE Satellite Solar Wind Day Averaged Data for 09 May
Speed: 777 km/sec Density: 2.2 p/cc Temp: 160000 K Bz: -1 nT
(Courtesy Space Environment Center, Boulder USA)
ACE data can be incorrect during strong proton events.
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IPS Radio and Space Services | email: asfc at ips.gov.au
PO Box 1386 | WWW: http://www.ips.gov.au
Haymarket NSW 1240 AUSTRALIA | FTP: ftp://ftp.ips.gov.au
tel: +61 2 9213 8010 | fax: +61 2 9213 8060
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