[Ips-dsgr] ASWFC Daily Report - 19 February 25 issued 2330 UT on 19 Feb 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Feb 20 10:30:49 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 FEBRUARY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 FEBRUARY AND FORECAST FOR 20 FEBRUARY - 22 FEBRUARY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Feb: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Feb: 178/131
1B. SOLAR FORECAST
20 Feb 21 Feb 22 Feb
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 19-Feb was at the R0 level.
Most solar regions are currently minor with AR3996 (S17E12, beta-gamma)
and AR3998 (S14E33, beta-gamma) the two more slightly complex
regions. Both these regions exhibited initial development and
then some subsequent decay in their intermediate spots. The largest
flare was a C4.2 from minor region AR3997 (N02W04, beta) at 19/1049UT.
There are currently eight numbered sunspot regions visible on
the solar disk. All other sunspot regions are either stable or
in decay. A small approximately 4 degree long filament located
at S20W60 erupted during the interval 19/0615-0656UT. This filament
eruption was followed by narrow plasma ejecta to the southwest
visible in GOES SUVI imagery from 19/0644UT. The northern section
of a solar filament located at S15W38-S05W45 erupted at 19/1020UT
and a small 10 degree long filament located at S10W05 erupted
at 19/1946UT. Solar activity is expected to be at R0-R1 levels
over 20-22 Feb. S0 solar radiation storm conditions were observed
on 19-Feb. S0 conditions are expected on 20-22 Feb. No significant
Earth-directed CMEs have been observed up to 19/1800UT. A narrow
southwest directed minor CME was observed from 19/0724UT in LASCO
C2 associated with the plasma ejecta/small filament eruption
over the interval 19/0615-0656UT. This minor CME has been modelled
as an Earth miss. The filament section eruption at 19/1020UT
did not appear to have an associated CME. LASCO imagery will
be checked as it becomes available for the small filament eruption
at 19/1946UT. The solar wind speed on UT day 19-Feb slowly declined,
ranging between 434 and 522 km/s and is currently near 450 km/s.
The peak total interplanetary field strength (IMF, Bt) was 7
nT and the north-south IMF component (Bz) range was +7 to -7
nT. The IMF Bz component became mildly southward from 19/1600UT.
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 19 Feb: G0
Estimated Indices 19 Feb : A K
Australian Region 9 32321232
Cocos Island 7 32211231
Darwin 9 32321232
Townsville 10 32321233
Learmonth 11 32321242
Alice Springs 9 32321232
Gingin 12 42321242
Canberra 9 32320232
Kennaook Cape Grim 14 33421333
Hobart 13 33421332
Estimated Antarctic Regional K Indices 19 Feb :
Macquarie Island 12 33421232
Casey 25 45532343
Mawson 42 55553265
Observed Regional daily pc3 Indices 19 Feb :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 6 (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 19 Feb : A
Fredericksburg 18
Planetary 22
Observed AFr/Ap Indices 18 Feb : A K
Fredericksburg 10
Planetary 10 3210 1324
2B. MAGNETIC FORECAST
Date Ap Conditions
20 Feb 10 G0
21 Feb 8 G0
22 Feb 5 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 19-Feb. In the Antarctic region G1 geomagnetic
conditions were observed at Casey and Mawson and G0 conditions
were observed at Macquarie Island. G0 geomagnetic conditions
are expected over 20-22 Feb as the recent mild geomagnetic influence
from a coronal hole wind stream declines.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 Feb Normal Fair-normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 Feb Normal Normal Normal-fair
21 Feb Normal Normal Normal-fair
22 Feb Normal Normal Normal
COMMENT: HF radio propagation conditions were fair to normal
on 19-Feb, with mildly degraded conditions at middle to high
latitudes. Mostly normal HF conditions are expected over 20-22
Feb.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 Feb 144
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 20-25%.
Niue Island Region:
Enhanced by 40% during local day.
Enhanced by 25% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Mostly near predicted monthly values.
Enhanced by 15-30% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% over the UT day.
Strong spread F observed at times.
Monthly T index:
Month T index
Jan 124
Feb 118
Mar 115
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
20 Feb 145 Near to 15% above predicted monthly values
21 Feb 145 Near to 15% above predicted monthly values
22 Feb 145 Near to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 19-Feb in
the Australian region were near predicted monthly values with
southern Australian region MUFs becoming enhanced by up to 15-30%
after local dawn this morning. Mild spread F was observed at
Hobart during local night hours. MUFs are expected to be near
predicted monthly values to 15% enhanced over 20-22 Feb.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 Feb
Daily Proton Fluence >1 MeV: 7.8E+05
Daily Proton Fluence >10 MeV: 1.7E+04
Daily Electron Fluence >2 MeV: 4.90E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 7%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B9.9
DSCOVR Satellite Solar Wind Day Averaged Data for 18 Feb
Speed: 484 km/sec Density: 7.5 p/cc Temp: 195000 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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