[Ips-dsgr] ASWFC Daily Report - 25 February 23 issued 2330 UT on 25 Feb 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Feb 26 10:30:53 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 FEBRUARY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 FEBRUARY AND FORECAST FOR 26 FEBRUARY - 28 FEBRUARY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Feb: R2
Flares Max Fadeout Freq. Sectors
M6/-- 1944UT probable lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Feb: 152/107
1B. SOLAR FORECAST
26 Feb 27 Feb 28 Feb
Activity R1-R2 R1-R2 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 155/109 155/109 150/105
COMMENT: Solar activity on UT day 25-Feb reached R2 levels, with
an M6.3 flare at 25/1940UT from AR3229 (N26W45, beta). An R1
flare of M1.1 was also observed at 25/1540UT from AR3236 (S26W03,
beta). There are currently 6 numbered sunspot regions on the
solar disk. AR3234 (N25E08, beta-delta), AR3235 (N19W15, beta)
ad AR3236 (S26W03, beta) have all shown slight growth in their
trailer spots. AR3229, while currently the most flare productive
sunspot region, has shown decay. All other sunspot regions are
stable. Solar activity is expected to be at R1-R2 levels over
26-28 Feb. The CME mentioned in yesterday's report, first observed
at 24/2036UT which was associated with a filament eruption and
M3.7 flare from AR3229 has been further analysed and is now expected
to impact Earth late 26-Feb to early 27-Feb with a side-on blow,
as the bulk of the ejecta is likely to pass above Earth. A filament
eruption was observed in H-alpha imagery alongside the M6.3 flare
at 25/1940UT, and early images of a CME are available from STEREO-A.
A preliminary analysis has been done and a glancing blow may
be expected on 28/0500UT ± 12 hours. No other CMEs were observed.
The solar wind speed on UT day 25-Feb was on a slightly declining,
steady trend and ranged from 488 to 394 km/s, and is currently
near 440 km/s. The total peak interplanetary magnetic field (IMF,
Bt) was 11 nT and the north-south IMF component (Bz) range was
+8 to -8 nT, with a period of southward Bz from 25/1400-1845UT.
The solar wind speed is expected to increase over 26-28 Feb due
to the onset of an equatorial coronal hole wind stream, combined
with the anticipated arrival of a CME first observed 24/2036UT
and a second one first observed 25/1938UT. The combination of
the M3.7 and M6.3 solar flares from AR3229 has caused an increase
in the energetic protons, and continued flaring may produce
S1 conditions on 26-27 Feb.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Feb: G0
Estimated Indices 25 Feb : A K
Australian Region 9 11122324
Cocos Island 6 22111322
Darwin 9 11122324
Townsville 9 11122324
Learmonth 8 11132323
Alice Springs 8 00122324
Gingin 7 11121323
Canberra 7 00121324
Hobart 10 10232324
Estimated Antarctic Regional K Indices 25 Feb :
Macquarie Island 12 00133443
Casey 11 13332233
Mawson 17 32223354
Observed Regional daily pc3 Indices 25 Feb :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 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 25 Feb : A
Fredericksburg 7
Planetary 10
Observed AFr/Ap Indices 24 Feb : A K
Fredericksburg 4
Planetary 5 2111 2111
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Feb 20 Initially G0, then G1-G2
27 Feb 28 G1-G2, chance of G3
28 Feb 20 G1-G2
COMMENT: ASWFC Geomagnetic Warning 7 was issued on 25 February
and is current for 27-28 Feb. G0 geomagnetic conditions were
observed in the Australian region on UT day 25-Feb. Mostly G0
geomagnetic conditions were observed in the Antarctic region,
with an isolated period of G1 at Mawson. G1-G2 conditions are
expected by late 26-Feb and 27-Feb, with a chance of isolated
G3 periods, due to the combination of an anticipated impact from
a CME first observed on 24/2036UT and equatorial coronal hole
wind stream. Further G1-G2 activity may be expected on 28-Feb
due to a second anticipated CME impact first observed 25/1938.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Feb Normal Normal Normal
PCA Event : 10MeV Proton/PCA Event Began 26 02 2023 0800UT and is in progress
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Feb Normal-fair Normal-fair Poor(PCA)
27 Feb Fair Fair-poor Fair-poor
28 Feb Normal-fair Fair Fair-poor
COMMENT: Degraded HF conditions may be expected on 26-Feb, due
to PCA from an S1 event that began at 25/2110UT, particularly
in high latitude regions. Further degraded HF conditions are
expected over 27-28 Feb due to anticipated geomagnetic activity.
Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Feb 142
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 25% during local day.
Enhanced by 75% during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Near predicted monthly values during local day.
Enhanced by 40% during local night.
Northern Australian Region:
Enhanced by 20% during local day.
Enhanced by 60% during local night.
Enhanced by 30% after local dawn.
Southern Australian Region:
Enhanced by 20% during local day.
Enhanced by 35% during local night.
Enhanced by 20% after local dawn.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Enhanced by 30% over the UT day.
Monthly T index:
Month T index
Jan 119
Feb 75
Mar 76
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
26 Feb 125 20-30% above predicted values
27 Feb 80 Near predicted monthly values
28 Feb 70 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 22 was issued on
24 February and is current for 25-27 Feb. Maximum usable frequencies
(MUFs) in the Australian region on UT day 25-Feb were mostly
20-35% enhanced, and enhancements up to 60% were observed in
the northern Australian region during local night. Sporadic-E
was observed briefly in Learmonth and Brisbane during local dawn
hours. MUFs are expected to be 20-30% above predicted monthly
values on 26-Feb, then returning to near predicted monthly values
due to anticipated geomagnetic activity over 27-28 Feb. Shortwave
fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Feb
Daily Proton Fluence >1 MeV: 2.2E+05
Daily Proton Fluence >10 MeV: 3.4E+04
Daily Electron Fluence >2 MeV: 1.60E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.1
DSCOVR Satellite Solar Wind Day Averaged Data for 24 Feb
Speed: 500 km/sec Density: 9.7 p/cc Temp: 198000 K Bz: 5 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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