[Ips-dsgr] ASWFC Daily Report - 03 September 25 issued 2330 UT on 03 Sep 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Sep 4 09:30:48 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/03 SEPTEMBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 03 SEPTEMBER AND FORECAST FOR 04 SEPTEMBER - 06 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 03 Sep: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 03 Sep: 180/133
1B. SOLAR FORECAST
04 Sep 05 Sep 06 Sep
Activity R0 to R1 R0 to R1 R0 to R1
Fadeouts Possible Possible Possible
10.7cm/SSN 180/133 178/131 175/129
COMMENT: Solar activity on UT day 03-Sep was at the R0 level,
with no significant flaring activity. There are currently thirteen
numbered sunspot regions visible on the solar disk. AR4197 (S18W65,
beta) is the most magnetically complex region on the disk but
appears stable. AR4207 (N30E28, beta) and AR4210 (N09E43, beta)
are both showing growth in its intermediate spots and has also
been responsible for some minor flaring. All other sunspot regions
are either stable or in decay. Solar activity is expected to
be at the R0-R1 level over 04-06 Sep. S0 solar proton conditions
were observed on UT day 03-Sep. S0 solar proton conditions are
expected over 04-06 Sep. No Earth-directed CMEs have been observed.
The solar wind speed on UT day 03-Sep decreased from 540 to 449
km/s and is currently near 447 km/s. The peak total interplanetary
magnetic field strength (IMF, Bt) was 12 nT and the north-south
IMF component (Bz) range was -5 to +3 nT. A recurrent southern
hemisphere coronal hole is currently crossing the central meridian
and is likely to influence the solar wind from 06-Sep.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 03 Sep: G0
Estimated Indices 03 Sep : A K
Australian Region 5 22221021
Cocos Island 4 22121020
Darwin 5 22221121
Townsville 4 22221011
Learmonth 6 32222021
Alice Springs 5 22221021
Gingin 6 22221130
Canberra 4 22211021
Kennaook Cape Grim 5 22211121
Hobart 5 22211121
Estimated Antarctic Regional K Indices 03 Sep :
Macquarie Island 7 33321020
Casey 11 43331031
Mawson 27 53442163
Observed Regional daily pc3 Indices 03 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 11 (Quiet)
Canberra 8 (Quiet)
Hobart 28 (Quiet to 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 and have been shown to be
well correlated with rejection of high resolution aeromagnetic
survey flight-line data.
NOTE: Indices may have been generated from data obtained in
cooperation with the following organisations: Geoscience Australia,
University of Newcastle Space Physics Group, Australian Government
Antarctic Division and International Center for Space Weather
Science and Education, Japan.
Estimated AFr/Ap Indices 03 Sep : A
Fredericksburg 11
Planetary 14
Observed AFr/Ap Indices 02 Sep : A K
Fredericksburg 34
Planetary 14 5444 3454
2B. MAGNETIC FORECAST
Date Ap Conditions
04 Sep 10 G0
05 Sep 14 G0
06 Sep 20 G0-G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 03-Sep. G1 geomagnetic conditions were observed
in the Antarctic region. G0 geomagnetic conditions are expected
on 04-05 Sep. G0-G1 geomagnetic conditions are expected on 06-Sep
due to a recurrent southern hemisphere coronal hole moving into
a geoeffective position.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
03 Sep Normal Normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
04 Sep Normal Normal Normal-fair
05 Sep Normal Normal Normal-fair
06 Sep Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 03-Sep were
mostly normal at low and mid latitudes and fair to poor at high
latitudes. HF radio propagation conditions are expected to be
normal to fair over 04-05 Sep. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
03 Sep 97
Observed Australian Regional MUFs
Cocos Island Region:
No data available during local day.
No data available during local night.
Niue Island Region:
Enhanced by 15% during local day.
Enhanced by 30% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Depressed by 25% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% over the UT day.
Monthly T index:
Month T index
Aug 96
Sep 92
Oct 90
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
04 Sep 110 Near to 15% above predicted monthly values
05 Sep 105 Near predicted monthly values
06 Sep 107 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 82 was issued on
3 September and is current for 3-5 Sep. Maximum usable frequencies
(MUFs) in the northern Australian region on UT day 03-Sep were
near predicted monthly values. MUFs in the southern Australian
region were depressed by 25% during local day and near predicted
values during local night. Spread F was observed in Hobart and
Canberra during local night. MUFs are expected to be near to
15% enhanced over 04 Sep UT and predicted monthly values over
05-06 Sep. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 02 Sep
Daily Proton Fluence >1 MeV: 7.7E+07
Daily Proton Fluence >10 MeV: 2.8E+04
Daily Electron Fluence >2 MeV: 1.00E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 02 Sep
Speed: 568 km/sec Density: 5.6 p/cc Temp: 55800 K Bz: 5 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
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Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
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