[Ips-dsgr] ASWFC Daily Report - 20 March 25 issued 2331 UT on 20 Mar 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri Mar 21 10:31:20 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/20 MARCH 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 20 MARCH AND FORECAST FOR 21 MARCH - 23 MARCH
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 20 Mar: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Mar: 170/124
1B. SOLAR FORECAST
21 Mar 22 Mar 23 Mar
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 170/124 165/119 155/109
COMMENT: Solar activity on UT day 20-Mar was R0, with no significant
solar flares. There are currently nine numbered sunspot regions
on the solar disk. AR4034 (S17E03, beta) and AR4035 (N15E10,
beta) have shown some minor growth, but all other sunspots are
either stable or in decay. Solar activity is expected to be R0-R1
over 21-23 Mar.
Two CMEs were observed off the western limb on UT day 20-Mar; both
are likely to originate from ex-region AR4018, now expected to be
more than 10 degrees over the western limb. These CMEs are therefore
not expected to be geoeffective. The CME featured in yesterday's report
has been further analysed to suggest that it may pass nearby the Earth
late on 22-Mar or else early 23-Mar, but is not expected to have a
full impact.
S0 solar radiation storm conditions were observed on UT day 20-Mar,
although there was a small proton response mostly likely from
the CME activity off the western limb. S0 solar radiation storm
conditions are mostly expected over 21-23 Mar.
The solar wind was near background conditions on UT day 20-Mar. The peak total
interplanetary field strength (IMF, Bt) was 6 nT and the north-south
IMF componant range (Bz) was +4 to -4 nT. The solar wind speed
was on a slow decline and ranged from 500 km/s to 400 km/s. The
solar wind speed is expected to be at background levels on 21-Mar,
and may become mildly disturbed on 22-Mar due to a CME passing
nearby. Connection to an equatorial coronal hole is expected
by 23-Mar, increasing the solar wind speed from then. The CME
from 16-Mar likely passed nearby the Earth on 19-Mar and is no
longer in the forecast.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 20 Mar: G0
Estimated Indices 20 Mar : A K
Australian Region 3 12211101
Cocos Island 3 22201001
Darwin 4 22211102
Townsville 4 12212111
Learmonth 5 22211112
Alice Springs 3 11201102
Gingin 4 22111012
Canberra 3 12212001
Kennaook Cape Grim 4 12222001
Hobart 4 12212101
Estimated Antarctic Regional K Indices 20 Mar :
Macquarie Island 5 12232010
Casey 11 44312012
Mawson 20 24421036
Observed Regional daily pc3 Indices 20 Mar :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 2 (Quiet)
Gingin 27 (Quiet to unsettled)
Canberra 16 (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 20 Mar : A
Fredericksburg 6
Planetary 6
Observed AFr/Ap Indices 19 Mar : A K
Fredericksburg 19
Planetary 24 2442 4453
2B. MAGNETIC FORECAST
Date Ap Conditions
21 Mar 8 G0
22 Mar 12 G0, very slight chance of G1
23 Mar 14 G0-G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 20-Mar. G0 geomagnetic conditions
are mostly expected over 21-22 Mar; there is a slight chance
for G1 on late 22-Mar due to possible influence from a CME expected
to pass nearby. Further bouts of G1 are possible on 23-Mar due
to a coronal hole.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
20 Mar Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
21 Mar Normal Normal Normal
22 Mar Normal Normal Fair
23 Mar Normal Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 20-Mar were
mostly normal. Some depressions were observed in the southern
hemisphere during the first half of the UT day. HF radio propagation
conditions are expected to be normal over 21-23 Mar, and may
become mildly degraded on 23-Mar due to coronal hole activity.
Equatorial scintillation is likely over this period.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
20 Mar 135
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 15% during local day.
Enhanced by 20% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Mostly near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% 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
21 Mar 130 Near predicted values to 15% enhanced
22 Mar 125 Near predicted monthly values to 15% enhanced
23 Mar 110 Near predicted monthly values to 15% depressed
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 20-Mar were near predicted values to 15% enhanced.
Some minor spread-F was observed in Hobart. Scintillation was
observed in Darwin and Weipa from 1115 UT to 1310 UT with a maximum
S4 index of 1.0. MUFs are expected to be near predicted values
to 15% enhanced over 21-22 Mar; MUFs may become depressed by
15% by 23-Mar. Equatorial scintillation is likely.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 19 Mar
Daily Proton Fluence >1 MeV: 4.9E+05
Daily Proton Fluence >10 MeV: 1.7E+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: C1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 19 Mar
Speed: 486 km/sec Density: 12.1 p/cc Temp: 227000 K Bz: -4 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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