[Ips-dsgr] ASWFC Daily Report - 09 April 25 issued 2330 UT on 09 Apr 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Apr 10 09:30:59 AEST 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/09 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 09 APRIL AND FORECAST FOR 10 APRIL - 12 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 09 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 09 Apr: 167/121
1B. SOLAR FORECAST
10 Apr 11 Apr 12 Apr
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 160/114 155/109 155/109
COMMENT: Solar activity on UT day 9-Apr was R0. Solar region
AR4048 (S15W70, beta) and AR4055 (N07W18, beta-gamma) both produced
C class flares, with AR4055 producing the largest a C9 flare
at 09/1730UT. Region AR4048 continues to decay and AR4055 shows
slight development. A new medium sized solar region at N05E85
is rotating onto the solar disk. This region has shown activity
in the past 24 hours and solar activity may increase in coming
days. There are currently eight numbered sunspots on the solar
disk and one unnumbered region. A small 8 degree long solar filament
erupted at 09/0453UT located at N25E35. A 15 degree long solar
filament located at S25E05 erupted at 09/0937UT. All other sunspot
regions are stable or in decay. Solar activity is expected to
be R0-R1 over 10-12 Apr. S0 solar radiation storm conditions
were observed on UT day 9-Apr. S0 solar radiation storm conditions
are expected over 10-12 Apr. No Earth directed CMEs were observed.
The small filament eruption in the northeast solar quadrant was
associated with a non Earth directed CME directed steeply to
the north northeast from 09/0548UT. The filament eruption in
the southeast solar quadrant did not appear to have an associated
CME. A very faint narrow CME was observed to the south southeast
from 09/1048UT. The solar wind environment on UT day 09-Apr was
moderately enhanced due to a solar coronal hole wind stream.
A coronal hole in the southern solar hemisphere is crossing the
solar central meridian. The solar wind speed ranged from 454
km/s to 583 km/s and is currently at 505 km/s. The peak total
interplanetary field strength (IMF, Bt) was 10 nT and the north-south
IMF component range (Bz) was +8 to -8 nT. The solar wind is expected
to remain enhanced over 10-11 Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 09 Apr: G0
Estimated Indices 09 Apr : A K
Australian Region 16 33343333
Cocos Island 8 32222231
Darwin 12 33233322
Townsville 16 33343333
Learmonth 14 32333333
Alice Springs 15 33333333
Gingin 15 32343333
Canberra 18 32353333
Kennaook Cape Grim - --------
Hobart 19 33353333
Estimated Antarctic Regional K Indices 09 Apr :
Macquarie Island 30 32465532
Casey 23 55343233
Mawson 47 55543474
Observed Regional daily pc3 Indices 09 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 2 (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 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 09 Apr : A
Fredericksburg 17
Planetary 25
Observed AFr/Ap Indices 08 Apr : A K
Fredericksburg 20
Planetary 24 3442 5444
2B. MAGNETIC FORECAST
Date Ap Conditions
10 Apr 18 G0, chance G1
11 Apr 18 G0, chance G1
12 Apr 10 G0
COMMENT: ASWFC Geomagnetic Warning 26 was issued on 6 April and
is current for 9-10 Apr. G0 geomagnetic conditions were observed
in the Australian region on UT day 9-Apr, with mildly enhanced
geomagnetic activity due to a coronal hole wind stream. In the
Antarctic region G1-G3 periods were observed. A planetary G1
period was observed early in the UT day. G0, chance G1 geomagnetic
conditions are expected over 10-11 Apr due to the ongoing mild
influence of a coronal hole wind stream.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
09 Apr Normal Fair-normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
10 Apr Normal Normal-fair Fair
11 Apr Normal Normal-fair Fair
12 Apr Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on 09-Apr were generally
fair to normal, with fair conditions at middle to high latitudes.
Similar conditions are expected for 10-11 Apr with improved HF
conditions on 12-Apr for high latitudes.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
09 Apr 133
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 25% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Mostly near predicted monthly values.
Enhanced by 20% after local dawn.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Enhanced by 20% after local dawn.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 25% over the UT day.
Monthly T index:
Month T index
Mar 126
Apr 115
May 113
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
10 Apr 125 Briefly 15% depressed after dawn to near predicted
monthly values to 15% enhanced
11 Apr 125 Briefly 15% depressed after dawn to near predicted
monthly values to 15% enhanced
12 Apr 145 Near predicted monthly values to 15% enhanced
COMMENT: ASWFC SWF HF Communications Warning 35 was issued on
8 April and is current for 9-10 Apr. Maximum usable frequencies
(MUFs) in the Australian region on UT day 9-Apr were near predicted
values to 20% enhanced. Strong spread-F was observed at Hobart
during local night hours. MUFs are expected to be generally near
predicted values over 10-12 Apr. MUFs in the southern Australian
region may be briefly depressed by 15-20% after local dawn due
to ongoing mild geomagnetic activity. Northern Australian region
MUFs are expected to be 15% enhanced.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 08 Apr
Daily Proton Fluence >1 MeV: 7.2E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 2.90E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:18%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.3
DSCOVR Satellite Solar Wind Day Averaged Data for 08 Apr
Speed: 504 km/sec Density: 10.3 p/cc Temp: 261000 K Bz: -1 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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