[Ips-dsgr] ASWFC Daily Report - 23 March 23 issued 2330 UT on 23 Mar 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Fri Mar 24 10:30:57 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 MARCH 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 MARCH AND FORECAST FOR 24 MARCH - 26 MARCH
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Mar: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Mar: 151/106
1B. SOLAR FORECAST
24 Mar 25 Mar 26 Mar
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 150/105 145/99 145/99
COMMENT: Solar activity on UT day 23-Mar was at the R0 level,
with no significant flaring. There is no region of significance
currently on the solar disk. There are currently 5 numbered sunspot
regions on the solar disk and three new regions located at N18E15,
N26W15 and S14E20. Solar region AR3259(S21E11, beta) is showing
slight growth. Solar activity is expected to be at R0-R1 levels
over 24-26 Mar. No new significantly Earth directed CMEs have
been observed. A narrow south east directed CME was observed
in LASCO C2 from 23/0548UT but is considered not Earth directed.
The solar wind magnetic field parameters became unexpectedly
enhanced over the past 24 hours, with a gradual increase in the
solar wind total magnetic field strength together with an increasing
southward drift of the interplanetary magnetic field (IMF) Bz
component. The solar wind speed and temperature remained relatively
steady. The solar wind density gradually increased from 23/05-14UT
then reduced. The ACE satellite EPAM low energy ion flux showed
an increase in flux peaking at around 23/1000UT, suggesting a
slow/weak glancing blow CME signature possibly from a recent
filament eruption, though the slow drift in southward IMF strength
could also suggest a coronal hole wind stream IMF precursor but
as yet there is no increase in the solar wind speed evident or
subsequent reversal in the IMF Bz orientation. In addition a
Forbush decrease was observed later in the UT day on 23-Mar further
suggesting a slow CME arrival as a contributor. The solar wind
speed on UT day 23-Mar was steady ranging from 443 to 513 km/s,
and is currently near 468 km/s. The peak total interplanetary
field strength (IMF, Bt) was 22 nT and the north-south IMF component
(Bz) range was +10 to -18 nT. A steady southward orientation
in Bz (-15nT) was observed from 23/1700UT. An extended period
of elevated solar wind conditions is likely from a coronal hole
in the southern solar hemisphere, whilst this coronal hole is
broad in longitudinal extent it is located quite far south which
may reduce induced geomagnetic activity. The coronal hole has
a narrow trans equatorial extension on its eastern side, though
at this stage this feature is now past solar central meridian
and in SDO193 imagery appears to have reduced in area. This extension
may elevate solar wind speeds on 26-27-Mar.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 23 Mar: G2
Estimated Indices 23 Mar : A K
Australian Region 30 21336455
Cocos Island 24 22235355
Darwin 25 21236345
Townsville 33 21456445
Learmonth 29 21236455
Alice Springs 27 21236355
Gingin 28 21336355
Canberra 27 11336445
Hobart 28 11346445
Estimated Antarctic Regional K Indices 23 Mar :
Macquarie Island 53 11567465
Casey 21 24434344
Mawson 55 23255485
Observed Regional daily pc3 Indices 23 Mar :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 22 (Quiet to unsettled)
Canberra 29 (Quiet to unsettled)
Hobart 68 (Active)
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 23 Mar : A
Fredericksburg 23
Planetary 44
Observed AFr/Ap Indices 22 Mar : A K
Fredericksburg 14
Planetary 16 3334 3331
2B. MAGNETIC FORECAST
Date Ap Conditions
24 Mar 45 G1-G2, chance of isolated G3 period early in UT
day.
25 Mar 25 G0-G1
26 Mar 18 G0-G1
COMMENT: ASWFC Geomagnetic Warning 14 was issued on 23 March
and is current for 24 Mar only. Unexpected G1-G2 geomagnetic
activity was observed in the Australian region on UT day 23-Mar
possibly due to a glancing blow from a recent filament eruption
and possible coronal hole wind stream entry effects. G1-G4 conditions
were observed in the Antarctic region. G1-G2 conditions are now
expected for the first half of 24 Mar. With the current sustained
southward IMF conditions there is a chance for the regional magnetic
field to reach G3 early in the UT day on 24-Mar. In general an
extended interval of mildly enhanced geomagnetic activity is
expected 25-27 Mar due to a broad coronal hole located in the
southern solar hemisphere.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
23 Mar Normal Normal-poor Fair-poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
24 Mar Normal Poor-fair Poor-fair
25 Mar Normal Normal-fair Poor-fair
26 Mar Normal Normal-fair Fair
COMMENT: HF propagation conditions on 23-Mar became degraded
during the second half of the UT day due to unexpectedly strong
geomagnetic activity. Degraded HF conditions are now expected
for middle to high latitudes for 24-Mar. An extended period of
mildly degraded HF conditions for middle to high latitudes is
expected due to a broad solar coronal hole wind stream during
25-27 Mar. Middle to low latitude HF conditions are expected
to remain normal.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
23 Mar 141
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 20-85%
Niue Island Region:
Enhanced by 40-55%
Northern Australian Region:
Enhanced by 20-35%
Southern Australian Region:
Enhanced by 30% during local day.
Enhanced by 45% during local night.
Depressed by 15% after local dawn.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Feb 117
Mar 80
Apr 80
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
24 Mar 65 20% depressed/20% enhanced
25 Mar 75 15% depressed/20% enhanced
26 Mar 125 Near predicted monthly values/20% enhanced
COMMENT: Maximum usable frequencies (MUFs) on UT day 23-Mar in
the Australian region were generally enhanced by 20-85%. Unexpected
degraded HF conditions were observed during local night hours
for southern region Australia with strong spread F observed at
Canberra, Norfolk Island and Hobart. Aurora displays were seen
at Canberra overnight in association with overnight geomagnetic
storm activity. Southern region Australia MUFs are expected to
be depressed 15-20% today following the overnight geomagnetic
activity. MUFs for northern region Australia are expected to
remain enhanced by 20-30% over the next three days. In general,
degraded HF conditions during local night hours for southern
region Australia are possible during 25-27 Mar due to an expected
extended interval of mildly increased geomagnetic activity from
a broad solar coronal hole. Ionospheric scintillation was observed
23/1246-1359UT at Darwin and Weipa.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 22 Mar
Daily Proton Fluence >1 MeV: 1.4E+06
Daily Proton Fluence >10 MeV: 4.1E+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: B7.9
DSCOVR Satellite Solar Wind Day Averaged Data for 22 Mar
Speed: 524 km/sec Density: 10.9 p/cc Temp: 357000 K Bz: 0 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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