[Ips-dsgr] ASWFC Daily Report - 04 April 25 issued 2331 UT on 04 Apr 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sat Apr 5 10:31:08 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/04 APRIL 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 04 APRIL AND FORECAST FOR 05 APRIL - 07 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 04 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 04 Apr: 180/133
1B. SOLAR FORECAST
05 Apr 06 Apr 07 Apr
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 175/129 175/129 170/124
COMMENT: Solar activity on UT day 04-Apr was R0, with no significant
solar flares. Solar region AR4048 (S15W04, beta) has increased
in longitudinal extent, with small intermediates appearing ahead
of the trailer spot and with leader spot redistribution, though
perhaps appears to be showing overall decay. Small solar regions
AR4044 (N17W53, beta), AR4049 (S31W19, beta), AR4050 (N27W25,
beta) and AR4052 (S22W32, beta) have all slightly grown. All
regions are of the more simple alpha and beta magnetic classifications.
Two new very small regions have emerged at S12E28 and N08E52.
There are currently ten numbered sunspots on the solar disk.
All other sunspot regions are either stable or in decay. Solar
activity is expected to be R0-R1 over 05-07 Apr. No Earth directed
CMEs were observed on UT day 04-Apr. A southward CME was observed
from 04/1512UT which could not be correlated to on disk activity.
A northward CME was observed from 04/1636UT associated with an
erupting prominence on the north western solar limb at solar
latitude N30. S0 solar radiation storm conditions were observed
on UT day 04-Apr. The solar proton flux is declining to background
levels. S0 solar radiation storm conditions are expected over
05-07 Apr. The solar wind speed on UT day 04-Apr slightly increased
and ranged from 430 to 570 km/s. The solar wind speed is currently
near 524 km/sec. The mild increase in solar wind speed is considered
to be due to a small equatorial coronal hole. The peak total
interplanetary magnetic field strength (IMF, Bt) was 14 nT and
the north-south IMF component (Bz) range was +10 to -11 nT. The
IMF Bz component fluctuated mildly southward during the UT day.
The solar wind speed is expected to be moderately elevated on
05-Apr. The solar wind may begin to return to background conditions
by 06-Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 04 Apr: G0
Estimated Indices 04 Apr : A K
Australian Region 17 23334343
Cocos Island 14 22333343
Darwin 13 23333332
Townsville 15 23334333
Learmonth 22 33335443
Alice Springs 15 23334333
Gingin 23 32335354
Canberra 17 23344333
Kennaook Cape Grim 22 23345443
Hobart 22 23345443
Estimated Antarctic Regional K Indices 04 Apr :
Macquarie Island 39 24456554
Casey 18 34343333
Mawson 72 55554677
Observed Regional daily pc3 Indices 04 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 8 (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 04 Apr : A
Fredericksburg 28
Planetary 43
Observed AFr/Ap Indices 03 Apr : A K
Fredericksburg 21
Planetary 0 4344 4355
2B. MAGNETIC FORECAST
Date Ap Conditions
05 Apr 19 G0-G1
06 Apr 12 G0
07 Apr 8 G0
COMMENT: ASWFC Geomagnetic Warning 24 was issued on 1 April and
is current for 4-5 Apr. G0 geomagnetic conditions were observed
in the Australian region on UT day 04-Apr. In the Antarctic region
G1-G2 conditions were observed at Macquarie Island, G1-G3 conditions
at Maswon and G0 conditions observed at Casey. A single period
of G1 planetary geomagnetic conditions was observed. G0-G1 geomagnetic
conditions are expected on 05-Apr due to a wind stream from a
small equatorial coronal hole. Conditions are expected to ease
by 06-Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
04 Apr Normal Fair-normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
05 Apr Normal Normal Normal-fair
06 Apr Normal Normal Normal-fair
07 Apr Normal Normal Normal
COMMENT: HF radio propagation conditions on UT day 04-Apr were
fair to normal. HF radio propagation conditions are expected
to be fair to normal on 05-06 Apr and normal on 07-Apr, with
fair conditions restricted to higher latitudes.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
04 Apr 138
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Mostly near predicted monthly values.
Enhanced by 25% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 15% during local night.
Enhanced by 30% after local dawn.
Southern Australian Region:
Mostly near predicted monthly values.
Enhanced by 20% after local dawn.
Hobart MUFs 30% depressed after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 45% 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
05 Apr 125 Near predicted monthly values
06 Apr 125 Near predicted monthly values
07 Apr 125 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 04-Apr were near predicted values to 30% enhanced.
Spread F was observed at Hobart during local night hours. MUFs
are generally expected to be near predicted values over 05-07
Apr. Northern Australian region MUFs are expected to be near
predicted monthly values to 15% enhanced. Mild depressions of
15% may be experienced at times for the southern Australian region
over 05-06 Apr. Hobart MUFs are currently 30% depressed.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 03 Apr
Daily Proton Fluence >1 MeV: 2.8E+07
Daily Proton Fluence >10 MeV: 1.4E+05
Daily Electron Fluence >2 MeV: 6.30E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 03 Apr
Speed: 445 km/sec Density: 10.3 p/cc Temp: 102000 K Bz: 0 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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