[Ips-dsgr] ASWFC Daily Report - 20 February 25 issued 2330 UT on 20 Feb 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Fri Feb 21 10:30:59 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/20 FEBRUARY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 20 FEBRUARY AND FORECAST FOR 21 FEBRUARY - 23 FEBRUARY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 20 Feb: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Feb: 184/137
1B. SOLAR FORECAST
21 Feb 22 Feb 23 Feb
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 180/133 180/133 175/129
COMMENT: Solar activity on UT day 20-Feb was at the R0 level.
Solar region AR3998 (S14E17, beta-gamma) continues to grow. Nearby
solar region AR3996 (S17W04, beta) has increased in overall longitudinal
width, with some minor development in its intermediate spots.
A new currently small solar region has emerged at N17E23 and
a very small new region has rotated onto the solar disk at solar
latitude N10. There are currently eight numbered sunspot regions
visible on the solar disk. All other sunspot regions are either
stable or in decay. Very localised on disk plasma motion was
observed with a C8.1 flare from now decayed minor region AR3991
(S14W45) at 19/2345UT, with brief narrow coronal diming visible
in GOES SUVI 284 imagery on the southwest solar limb. A partial
filament eruption was observed in the far southeast solar quadrant
in SDO 304 imagery 20/0528UT located at S40E60. In GONG imagery
a very small solar filament located at S15W05 erupted at 20/1103UT
but appeared to fall back into the chromosphere. Solar activity
is expected to be at R0-R1 levels over 21-23 Feb. S0 solar radiation
storm conditions were observed on 20-Feb. S0 conditions are expected
on 21-23 Feb. No significant Earth-directed CMEs have been observed.
The C8.1 flare from solar region AR3991 was associated with a
minor southwest CME which has been modelled as an Earth miss.
An east directed CME visible from 20/1036UT could not be time
correlated to any on disk activity. Yesterday's small filament
eruption at S10W05 at 19/1946UT did not appear to have an associated
CME. Today's partial filament eruption in the far southeastern
solar quadrant appeared to be associated with a minor very narrow
southward (out of the ecliptic plane) directed CME visible from
20/0624UT. The solar wind speed on UT day 20-Feb slowly declined,
ranging between 397 and 490 km/s and is currently near 405 km/s.
The peak total interplanetary field strength (IMF, Bt) was 7
nT and the north-south IMF component (Bz) range was +6 to -6
nT. The IMF Bz component became mildly southward 20/0000-0454UT.
The solar wind speed is expected to continue to slowly decline
as recent coronal hole high speed wind stream effects gradually
reduce.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 20 Feb: G0
Estimated Indices 20 Feb : A K
Australian Region 2 22101001
Cocos Island 2 21111000
Darwin 2 21101001
Townsville 3 22111002
Learmonth 3 32101001
Alice Springs 2 21101001
Gingin 3 32101001
Canberra 2 22101001
Kennaook Cape Grim 2 22101001
Hobart 2 21101001
Estimated Antarctic Regional K Indices 20 Feb :
Macquarie Island 3 32100001
Casey 16 44531112
Mawson 13 54411001
Observed Regional daily pc3 Indices 20 Feb :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (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 Feb : A
Fredericksburg 8
Planetary 8
Observed AFr/Ap Indices 19 Feb : A K
Fredericksburg 13
Planetary 16 4341 1243
2B. MAGNETIC FORECAST
Date Ap Conditions
21 Feb 8 G0
22 Feb 5 G0
23 Feb 5 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 20-Feb. In the Antarctic region isolated G1
geomagnetic periods were observed at Casey and Mawson and G0
conditions were observed at Macquarie Island. G0 geomagnetic
conditions are expected over 21-23 Feb.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
20 Feb Normal Normal Fair-normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
21 Feb Normal Normal Normal-fair
22 Feb Normal Normal Normal
23 Feb Normal Normal Normal
COMMENT: HF radio propagation conditions were fair to normal
on 20-Feb, with mildly degraded conditions at high latitudes.
Mostly normal HF conditions are expected over 21-23 Feb.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
20 Feb 155
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 25% during local day.
Enhanced by 60% during local night.
Niue Island Region:
Enhanced by 20% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Southern Australian Region:
Enhanced by 20% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jan 124
Feb 118
Mar 115
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
21 Feb 145 Near to 15% above predicted monthly values
22 Feb 145 Near to 15% above predicted monthly values
23 Feb 145 Near to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 20-Feb in
the Australian region were near predicted monthly to 20% enhanced.
Mild spread F was observed during local night hours at Canberra
and Hobart. Ionospheric equatorial scintillation was observed
at Weipa during the interval 20/1053-1110UT. MUFs are expected
to be near predicted monthly values to 15% enhanced over 21-23
Feb.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 19 Feb
Daily Proton Fluence >1 MeV: 3.4E+05
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 1.20E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B9.9
DSCOVR Satellite Solar Wind Day Averaged Data for 19 Feb
Speed: 489 km/sec Density: 13.6 p/cc Temp: 252000 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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