[Ips-dsgr] IPS Daily Report - 27 July 06
Regional Warning Centre
rwc at ips.gov.au
Fri Jul 28 09:55:26 EST 2006
SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 27/2330Z JULY 2006 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 27 JULY AND FORECAST FOR 28 JULY - 30 JULY
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
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1A. SOLAR SUMMARY
Activity 27 Jul: Very low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Jul: 74/11
1B. SOLAR FORECAST
28 Jul 29 Jul 30 Jul
Activity Very low Very low Very low
Fadeouts None expected None expected None expected
10.7cm/SSN 75/13 75/13 75/13
COMMENT: Solar region 901 produced a couple of B-class flares
over the day and background X-ray flux increased slightly. Overall
activity remains very low however. A weak shock was detected
by the ACE spacecraft at the L1 point at ~13UT. This appears
to be the delayed onset of the coronal hole high speed solar
wind stream, possibly mixed with the very delayed CME shock front.
Vsw increased from 330km/sec and is now approaching 500km/sec.
IMF total field increased after the shock and Bx fluctated more
widely, mainly southwards, encouraging merging with the geomagnetic
field. Solar wind density made a step increase at the shock front
and temperature rose in its wake. What appears to be a small
CME loop was observed on the eastern solar limb late in the UT
day in SOHO spacecraft imagery, possibly indicating the approach
of an active region.
A possible weak shock was observed in the solar wind at 1300UT
on 27 Jul.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 Jul: Quiet
Estimated Indices 27 Jul : A K
Australian Region 4 11102222
Darwin 7 12103232
Learmonth 6 01112233
Culgoora 4 11102222
Camden 5 11112222
Canberra 3 10002222
Hobart 2 00002112
Casey(Ant) 5 11211123
Observed Regional daily pc3 Indices 27 Jul :
Charters 0 (Quiet)
asp NA
Springs NA
Culgoora 10 (Quiet)
Canberra 17 (Quiet)
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 27 Jul : A
Fredericksburg 5
Planetary 5
Observed AFr/Ap Indices 26 Jul : A K
Fredericksburg 5
Planetary 6 3111 1211
2B. MAGNETIC FORECAST
Date Ap Conditions
28 Jul 6 Quiet to unsettled
29 Jul 7 Quiet to unsettled
30 Jul 6 Quiet
COMMENT: Solar wind speed has increased to 550km/sec since the
weak shock front at 13UT associated with the delayed onset of
the the coronal hole, possibly mixed with the very delayed CME.
Solar wind temperature and density have also increased. This
all suggests greater viscous interaction with the geomagnetic
field. IMF total field has increased and the Bz north-south component
is fluctuating although mostly southward. This has caused merging
with the geomagnetic field and high latitude activity has already
increased significantly. A weak magnetic impulse was observed
at Australian mid-latitude stations at 1355UT and the field has
subsequently become slightly unsettled at mid-latitudes. The
combination of all the effects above are likely to make the field
unsettled for a couple of days. Coupling of the solar wind to
the geomagnetic field has been weaker than expected in this solstice
period so active conditions do not appear likely.
A weak (12nT) impulse was observed in the IPS magnetometer data
at 1355UT on 27 Jul.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 Jul Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 Jul Normal Normal Normal-poor
29 Jul Normal Normal Poor-normal
30 Jul Normal Normal Normal-fair
COMMENT: ndex and hence ionospheric support for HF is still slightly
enhanced above monthly medians. Ionising X-ray flux from AR901
has slightly increased which may slow the trend. Increased geomagnetic
activity from a high speed solar wind stream may also slightly
depress the ionsophere to offset this so overall conditions will
be slightly enhanced.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 Jul 21
Observed Australian Regional MUFs
about 10% above predicted monthly values
Predicted Monthly T index for July: 13
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
28 Jul 20 about 10% above predicted monthly values
29 Jul 17 near predicted monthly values
30 Jul 18 about 5% above predicted monthly values
COMMENT: Overall conditions are still enhanced across the region,
less than yesterday. Equatorial (northern) latitudes still show
strong enhancements around dusk, followed by night-time depletions
due to equatorial mechanisms. Slightly higher ionising X-ray
flux from solar AR901 to enhance the ionisphere will be competing
with increased geomagnetic activity from a coronal hole solar
wind speed increase, trying to depress the ionosphere. The nett
result is likely to be a still slightly enhance condition. High
latitudes are likely to be very disturbed for the next day or
two due to IMF Bz southwards causing merging with the geomag
field and enhancing ionospheric convection, coupled with the
effects of the shock front at 13UT and increased solar wind speeds/densities.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 Jul
Daily Proton Fluence >1 MeV: 5.0E+05
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 9.10E+05 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 0%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: A2.8
ACE Satellite Solar Wind Day Averaged Data for 26 Jul
Speed: 354 km/sec Density: 4.7 p/cc Temp: 48400 K Bz: 1 nT
(Courtesy Space Environment Center, Boulder USA)
ACE data can be incorrect during strong proton events.
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