[Ips-dsgr] ASWFC Daily Report - 19 March 25 issued 2331 UT on 19 Mar 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Mar 20 10:31:17 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 MARCH 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 MARCH AND FORECAST FOR 20 MARCH - 22 MARCH
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Mar: R1
Flares Max Fadeout Freq. Sectors
M1.5 2040UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Mar: 180/133
1B. SOLAR FORECAST
20 Mar 21 Mar 22 Mar
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 180/133 175/129 165/119
COMMENT: Solar activity on UT day 19-Mar was R1, with an isolated
M1.5 flare from AR4031 (N17W36, beta). There are currently 10
numbered sunspot regions on the solar disk ARs 4026 (S20W42,
beta) and 4031 have both grown and matured, and will likely decay
in the coming days. Other regions 4021 (S06W45, beta), 4028 (S18W18,
beta), 4034 (S17E15, beta) and 4035 (N15E47, beta) have all grown
in the past day, however growth of all of these spots has been
minimal. Despite the large number of sunspots on the disk currently,
most are relatively small and simple. Solar activity over 20-22
Mar is expected to be R0-R1.
A CME to the northeast can be seen from 0036 UT on 19-Mar. It appears
to be at least associated with a coronal streamer, which may have
erupted due to activity near AR4033 (N26E19, beta), although the timing
of this chain of events is questionable. Minimal coronal dimming is associated
with this event, suggesting its origin is not on the frontside
of the Sun, however some imagery from the STEREO-A coronagraph
does support a frontside event. Analysis of this CME is ongoing
as to whether it could be geoeffective.
Another CME to the northwest from 0512 UT has been assessed as farside.
No other CMEs were observed on UT day 19-Mar.
S0 solar radiation storm conditions were observed on UT day 19-Mar.
S0 solar radiation storm conditions are expected over 20-22 Mar.
The solar wind environment on UT day 19-Mar was mildly disturbed.
The solar wind speed, as reported by ACE, ranged between near 420 and
520 km/s. The peak total interplanetary field strength (IMF, Bt) was
13 nT and the north-south IMF component range (Bz) was +6 to -11 nT.
Bz was oriented southward for much of the start and end of the UT day.
The source of the disturbance was likely from a remnant coronal hole
that is currently too far west to be visible. The solar wind environment
is expected to possibly be disturbed on 20-Mar due to a CME that was first
observed on 16-Mar, and carry in to 21-Mar. Should the CME that
launched at 19/0036 UT have an Earth-directed component, there
is a chance it would arrive late in the forecast period.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 19 Mar: G0
Estimated Indices 19 Mar : A K
Australian Region 13 23332333
Cocos Island 11 23222342
Darwin 10 13332232
Townsville 13 23332333
Learmonth 15 33332343
Alice Springs 11 23332232
Gingin 17 33332352
Canberra 14 23432333
Kennaook Cape Grim 17 23443333
Hobart 19 13543333
Estimated Antarctic Regional K Indices 19 Mar :
Macquarie Island 31 14654443
Casey 17 33433243
Mawson 44 55443664
Observed Regional daily pc3 Indices 19 Mar :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 11 (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 19 Mar : A
Fredericksburg 19
Planetary 23
Observed AFr/Ap Indices 18 Mar : A K
Fredericksburg 13
Planetary 12 3322 3333
2B. MAGNETIC FORECAST
Date Ap Conditions
20 Mar 18 G0-G1 initially, to G1-G2
21 Mar 8 G0-G1
22 Mar 6 G0, chance G1
COMMENT: ASWFC Geomagnetic Warning 18 was issued on 19 March
and is current for 19-20 Mar.
G0 geomagnetic conditions were observed in the Australian region on
UT day 19-Mar. G0-G2 geomagnetic conditions were observed in the
Antarctic region. G0-G1 geomagnetic conditions were recorded
as the planetary average.
G0-G1 geomagnetic conditions are expected initially on UT day 20-Mar due to
recent
coronal hole activity, followed potentially by G1-G2 activity
later in the day due to a CME arrival, although this is low confidence.
Conditions are expected to continue into 21-Mar but easing. There
is a further possibility of G1 activity on UT day 22-Mar due
to a potential CME, however this is low confidence and final
analysis of this event is pending.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 Mar Normal Normal-fair Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 Mar Normal Normal-fair Fair
21 Mar Normal-fair Normal-fair Fair
22 Mar Normal Normal-fair Normal-fair
COMMENT: HF radio propagation conditions on UT day 19-Mar were
generally normal at low and middle latitudes, with some degradations
and depressions at high latitudes setting in near the end of
the UT day. HF radio propagation conditions are expected to be
somewhat degraded on 20-Mar due to recent coronal hole activity
and an anticipated CME. degradations may ease over 21-22 Mar,
however this is dependent on further CME analysis.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 Mar 145
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Enhanced by 20% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Southern Australian Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Feb 127
Mar 117
Apr 114
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
20 Mar 120 Near predicted values to 15% depressed
21 Mar 105 Near predicted values to 20% depressed
22 Mar 110 Near predicted monthly values to 15% depressed
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 19-Mar were near predicted values to 15% enhanced.
Significant spread-F was observed in Hobart during local night
hours. MUFs are expected to be near predicted values to 15-20%
depressed over 20-22 Mar; initially due to recent coronal hole
activity, followed by a CME impact, then potentially followed
by a third CME impact late in the period. Scintillation is possible
at low and high latitudes over 20-22 Mar.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 Mar
Daily Proton Fluence >1 MeV: 1.4E+05
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 4.00E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.1
DSCOVR Satellite Solar Wind Day Averaged Data for 18 Mar
Speed: 410 km/sec Density: 5.3 p/cc Temp: 108000 K Bz: -2 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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