[Ips-dsgr] ASWFC Daily Report - 21 March 26 issued 2330 UT on 21 Mar 2026 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Mar 22 10:30:50 AEDT 2026
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 MARCH 2026
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 21 MARCH AND FORECAST FOR 22 MARCH - 24 MARCH
STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 21 Mar: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Mar: 107/57
1B. SOLAR FORECAST
22 Mar 23 Mar 24 Mar
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 108/58 108/58 105/54
COMMENT: Solar activity on UT day 21-Mar was R0, with no solar
flares. There are currently three numbered sunspots on the solar
disk, however all are either stable or in decay. Solar activity
is expected to be mostly R0 over 22-24 Mar.
No Earth directed CMEs were observed on UT day 21-Mar.
S0 solar radiation storm conditions were observed on UT day 21-Mar.
S0 solar radiation storm conditions are expected over 22-24 Mar.
On UT day 21-Mar the solar wind environment was disturbed due to
two CME arrivals and connection to a coronal hole. The solar wind
speed ranged from 450 to 550 km/s and remains elevated. The interplanetary
field strength (IMF, Bt) was 39 nT and the north-south IMF component
range (Bz) was +31 to -25 nT. Several intermittent periods of
southward Bz were observed towards the beginning of the day,
but mostly northward Bz was observed during the strongest Bt.
The solar wind speed is expected to remain elevated over 22-24
Mar as a new coronal hole is expected to connect by 23-Mar, although
Bt is expected to be near nominal levels.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 21 Mar: Quiet to Minor
Storm
Estimated Indices 21 Mar : A K
Australian Region 27 55544222
Cocos Island 20 55333222
Darwin - --------
Townsville 30 65543322
Learmonth 28 55544232
Alice Springs 26 55543232
Gingin 27 55444333
Canberra 23 55443222
Kennaook Cape Grim 27 55544222
Hobart 27 55544222
Estimated Antarctic Regional K Indices 21 Mar :
Macquarie Island 28 45554322
Casey 46 66644533
Mawson 51 75553355
Observed Regional daily pc3 Indices 21 Mar :
Darwin NA
Townsville 2 (Quiet)
Learmonth 20 (Quiet)
Alice Springs 15 (Quiet)
Gingin 80 (Active)
Canberra 49 (Unsettled)
Hobart 60 (Unsettled)
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 21 Mar : A
Fredericksburg 33
Planetary 60
Observed AFr/Ap Indices 20 Mar : A K
Fredericksburg 25
Planetary 34 2344 3367
2B. MAGNETIC FORECAST
Date Ap Conditions
22 Mar 16 G0-G2
23 Mar 20 G0-G2
24 Mar 15 G0-G2
COMMENT: ASWFC Geomagnetic Warning 18 was issued on 20 March
and is current for 21-23 Mar. On UT day 21-Mar the geomagnetic
conditions in the Australian region were G1. Geomagnetic conditions
in the Antarctic region were G0-G3. The average planetary geomagnetic
conditions reached G3.This was due to the arrival of two CMEs
coupled with a coronal hole late on 20-Mar. G0-G2 geomagnetic
conditions are generally expected over 22-24 Mar; as residual
effects of the recent event subside on 22-Mar there remains a
small chance for isolated storm periods. A new coronal hole is
expected to connect with Earth by 23-Mar which may give further
cause for storm periods, continuing into 24-Mar.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
21 Mar Normal-fair Fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
22 Mar Normal-fair Normal-fair Fair
23 Mar Fair Fair Fair
24 Mar Normal-fair Normal-fair Fair
COMMENT: HF radio propagation conditions on UT day 21-Mar were
degraded due to geomagnetic storming at all latitudes. HF radio
propagation conditions are expected to be better on 22-Mar but
still mildly degraded. Further degradations are possible on 23-Mar
as Earth connects to another coronal hole, leaving lingering
degradations on 24-Mar.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
21 Mar 39
Observed Australian Regional MUFs
Cocos Island Region:
Depressed by 25% during local day.
Depressed by 30% during local night.
Niue Island Region:
No data available during local day.
No data available during local night.
Northern Australian Region:
Depressed by 15% during local day.
Depressed by 30% during local night.
Southern Australian Region:
Depressed by 30% during local day.
Depressed by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 35% over the UT day.
Monthly T index:
Month T index
Feb 98
Mar 87
Apr 85
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
22 Mar 65 Depressed by 10-20%
23 Mar 85 Depressed by 10-20%
24 Mar 90 Depressed by 10-20%
COMMENT: ASWFC HF Communications Warning 28 was issued on 21
March and is current for 22-24 Mar. Maximum usable frequencies
(MUFs) in the Australian region on UT day 21-Mar were depressed
up to 30% due to recent geomagnetic activity. Sporadic-E was
observed in Hobart. MUFs are expected to be depressed on 22-Mar,
however begin a slow recovery. MUFs may be depressed by 10-20%
over 22-24 Mar. Due to the onset of another coronal hole by 23-Mar,
MUFs are not expected to return to near predicted values in this
forecast period.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 20 Mar
Daily Proton Fluence >1 MeV: 3.4E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 5.10E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 7%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B2.6
DSCOVR Satellite Solar Wind Day Averaged Data for 20 Mar
Speed: 456 km/sec Density: 7.3 p/cc Temp: 47500 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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