[Ips-dsgr] ASWFC Daily Report - 01 October 25 issued 2330 UT on 01 Oct 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Oct 2 09:30:50 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/01 OCTOBER 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 01 OCTOBER AND FORECAST FOR 02 OCTOBER - 04 OCTOBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 01 Oct: R1
Flares Max Fadeout Freq. Sectors
M1.2 0226UT possible lower E. Asia/Aust.
M1.2 1650UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 01 Oct: 184/137
1B. SOLAR FORECAST
02 Oct 03 Oct 04 Oct
Activity R1, chance R2 R1, chance R2 R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 185/138 185/138 185/138
COMMENT: On UT day 1-Oct solar activity was R1 with two M1 level
solar flares shared between AR4230 (S10W49, beta) and AR4236
(N12E03, gamma). There are currently eleven numbered sunspot
regions on the solar disk. The cluster of sunspots on the solar
southwest, namely AR4230, AR4238 (S16W53,beta), and AR4239 (S10W43,
beta) have shown separation in their polarities to reduce complexity
but have grown in size. Similar behaviour was observed in the
cluster of sunspots in the solar northeast, namely with AR4233
(N19E13, beta) and AR4236 (N12E03, gamma). AR4241 (N16E45, beta)
has also shown some growth. All other sunspot regions are either
stable or in decay. Solar activity is expected to be R1, with
a chance of R2 over 2-4 Oct.
Three CMEs were observed on UT day 1-Oct, but none are considered
geoeffective.
S0 solar radiation storm conditions were observed on UT day 1-Oct.
S0 solar radiation storm conditions are expected over 2-4 Oct.
The solar wind environment on UT day 1-Oct was disturbed due to ongoing
effects from a recent co-rotating interaction region. The solar wind
speed ranged from near 600 to 870 km/s and is remaining steady. The peak
total interplanetary field strength (IMF, Bt) was 10 nT and the north-south
IMF component range (Bz) was +7 to -7 nT with some intermittent
periods of southward Bz towards the end of the day. The solar
wind speed is expected to remain enhanced over 2-4 Oct, particularly
as a new coronal hole connects with Earth by 3-Oct.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 01 Oct: G1
Estimated Indices 01 Oct : A K
Australian Region 22 33435343
Cocos Island 15 33333333
Darwin 22 33435343
Townsville 20 33435333
Learmonth 22 33335344
Alice Springs 22 33435343
Gingin 25 43335444
Canberra 19 33434343
Kennaook Cape Grim 28 44445443
Hobart 30 44545443
Estimated Antarctic Regional K Indices 01 Oct :
Macquarie Island 67 55667563
Casey 29 45445343
Mawson 95 67655865
Observed Regional daily pc3 Indices 01 Oct :
Darwin 13 (Quiet)
Townsville 0 (Quiet)
Learmonth 13 (Quiet)
Alice Springs 8 (Quiet)
Gingin 91 (Minor storm)
Canberra 71 (Active)
Hobart 131 (Severe 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 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 01 Oct : A
Fredericksburg 32
Planetary 43
Observed AFr/Ap Indices 30 Sep : A K
Fredericksburg 43
Planetary 75 5765 6656
2B. MAGNETIC FORECAST
Date Ap Conditions
02 Oct 16 G0-G1, chance G2
03 Oct 30 G1-G2
04 Oct 26 G1-G2
COMMENT: On UT day 1-Oct the Australian region reached G1 geomagnetic
conditions. The Antarctic region reached G3-G4 geomagnetic conditions.
Planetary conditions reached G2 and several periods of G1 were
observed throughout the day due to ongoing southward Bz solar
wind conditions. A new coronal hole is expected to connect with the Earth
on 3-Oct which may induce G1-G2 geomagnetic activity.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
01 Oct Fair Fair Poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
02 Oct Normal-fair Normal-fair Fair
03 Oct Normal-fair Fair Fair-poor
04 Oct Fair Fair Poor
COMMENT: HF radio propagation conditions on UT day 1-Oct were
poor at all latitudes, particularly at the beginning and the
end of the day, and particularly during local night hours. Scintillation
was observed at all latitudes in the northern hemisphere. HF
radio propagation conditions are expected to continue to be degraded
over 2-4 Oct, on a worsening trend towards the end of the period
when a new coronal hole connects with Earth. Scintillation is
possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
01 Oct 96
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 25% during local day.
Near predicted monthly values during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 20% during local night.
Enhanced by 30% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Southern Australian Region:
Depressed by 20% during local day.
Depressed by 20% during local night.
Depressed by 30% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Sep 109
Oct 89
Nov 89
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
02 Oct 100 Near predicted monthly values to 30% depressed
03 Oct 95 Near predicted monthly values to 30% depressed
04 Oct 90 Near predicted monthly values to 30% depressed
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 1-Oct were depressed up to 30% in the southern
regions but up to 15% enhanced in the northern regions. Signal
spreading was observed in Canberra, Perth and Hobart. Sporadic-E
was observed in Darwin and Perth. Conditions were generally degraded
in Darwin and Hobart during local night hours. MUFs are expected
to be near predicted values to 30% depressed over 2-4 Oct.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 30 Sep
Daily Proton Fluence >1 MeV: 5.0E+05
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 1.40E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.7
DSCOVR Satellite Solar Wind Day Averaged Data for 30 Sep
Speed: 465 km/sec Density: 4.9 p/cc Temp: 172000 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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