[Ips-dsgr] ASWFC Daily Report - 25 November 23 issued 2331 UT on 25 Nov 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Nov 26 10:31:11 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 NOVEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 NOVEMBER AND FORECAST FOR 26 NOVEMBER - 28 NOVEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: ** RED **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Nov: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Nov: 176/130
1B. SOLAR FORECAST
26 Nov 27 Nov 28 Nov
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 175/129 175/129 175/129
COMMENT: Solar activity on UT day 25-Nov was low. The larger
solar regions currently on disk have shown some decline in the
past 24 hours. Solar region AR3500(S17E36, beta-gamma-delta)
is currently the largest region on disk. Though magnetically
complex the magnetic gradients within the region are not steep
and this region has yet to produce significant flare activity.
This region has shown decay in the last 24 hours with an overall
increase in spot separation. Other solar regions of recent interest,
AR3490(N21W12, beta-delta), AR3492(N20E01, beta) and AR3502(N12E02,
beta) have also shown decline. Solar region AR3499(S18W22, beta-gamma)
has shown slight development in its intermediate spots, though
at present this region is not very large. Small solar region
AR3503(N20E70, alpha) has been recently numbered. No significantly
Earth directed CMEs have been observed in the past 24 hours.
A long duration C5 flare was observed beginning at 24/2220UT,
associated with minor plasma motion across solar regions AR3490
and AR3492. A narrow northward non Earth directed CME was observed
in coronagraph imagery following this minor long duration flare.
There are currently twelve numbered solar regions on the visible
solar disk. Solar activity is expected to be R0-R1 over 25-27
Nov. No significantly Earth directed CMEs have been observed.
The solar wind gradually rose early in the UT day on 25-Nov,
possibly ue to an earlier than expected coronal hole wind stream
onset, then becoming steady at around 480km/sec before a moderate
shock was observed at 25/0754UT. Solar wind speed increased to
approximately 550km/sec post shock arrival. The solar wind speed
is currently at 598km/sec. The shock was probably the edge of
a CME from a solar filament eruption on 22-Nov, with a more significant
Earth directed component than modelled. The peak total interplanetary
field strength (MF, Bt) was 18 nT and the north-south IMF component
(Bz) range was +12 to -16 nT. Strong southward fluctuations in
Bz were observed following the shock arrival. The solar wind
is expected to be moderately enhanced over 25-26-Nov due to a
combination of a coronal hole wind stream and a possible weak
CME arrival.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Nov: G1
Estimated Indices 25 Nov : A K
Australian Region 28 22455543
Cocos Island 17 32434432
Darwin 25 22445543
Townsville - --------
Learmonth 32 32555543
Alice Springs 31 22555543
Gingin 32 32455553
Canberra 23 22454443
Hobart 32 23455553
Estimated Antarctic Regional K Indices 25 Nov :
Macquarie Island 62 23666763
Casey 33 54554443
Mawson 58 34576654
Observed Regional daily pc3 Indices 25 Nov :
Darwin 0 (Quiet)
Townsville NA
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 18 (Quiet)
Canberra 32 (Quiet to unsettled)
Hobart 89 (Minor storm)
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 Nov : A
Fredericksburg 23
Planetary 35
Observed AFr/Ap Indices 24 Nov : A K
Fredericksburg 5
Planetary 5 1110 2222
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Nov 25 G1, chance G2 early in UT day.
27 Nov 16 G0, chance G1 early in UT day.
28 Nov 10 G0
COMMENT: ASWFC Geomagnetic Warning 71 was issued on 24 November
and is current for 26 Nov only. G1 geomagnetic conditions were
observed in the Australian region and G2 planetary conditions
on UT day 25-Nov. In the Antarctic region G2-G3 periods were
observed at Macquarie Island and Mawson, with G1 periods observed
at Casey. The stronger than expected geomagnetic activity was
due to a component of a CME observed on 22-Nov. A weak (23nT)
impulse was observed at 25/0835UT. A combination of coronal hole
wind stream and a weaker CME arrival is expected on 26-Nov inducing
G1 periods. G0 conditions are expected on 27-Nov.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Nov Normal Normal-poor Normal-poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Nov Normal Poor-fair Poor
27 Nov Normal Fair Poor-fair
28 Nov Normal Normal Normal-fair
COMMENT: HF radio communication conditions on UT day 25-Nov were
initially normal then became poor following geomagnetic storm
activity associated with a CME arrival. HF radio communication
conditions are expected to be strongly degraded for middle to
high latitudes on 26-Nov. Further degradations are possible 27-Nov.
Isolated shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Nov 114
Observed Australian Regional MUFs
Cocos Island Region:
Mostly near predicted monthly values.
Enhanced by 20% after local dawn.
Niue Island Region:
Mostly near predicted monthly values.
Depressed by 20% after local dawn.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Depressed by 30% after local dawn.
Southern Australian Region:
Enhanced by 20% during local day.
Enhanced by 30% during local night.
Depressed by 40% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% over the UT day.
Monthly T index:
Month T index
Oct 130
Nov 100
Dec 98
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
26 Nov 30 15 to 30% below predicted monthly values
27 Nov 70 Depressed 10 to 20%/near predicted monthly values
28 Nov 110 Near predicted monthly values
COMMENT: ASWFC HF Communications Warning 120 was issued on 25
November and is current for 26 Nov only. Maximum usable frequencies
(MUFs) were initially near predicted monthly values to 15% enhanced,
becoming depressed by up to 40% after local dawn this morning
following overnight geomagnetic storm activity. Strong spread-F
was observed at Hobart during local night hours. Australian regional
MUFs are expected to be depressed by 20-30% for 26-Nov. Further
less severe depressions may be experienced on 27-Nov.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Nov
Daily Proton Fluence >1 MeV: 1.5E+05
Daily Proton Fluence >10 MeV: 1.9E+04
Daily Electron Fluence >2 MeV: 3.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 24 Nov
Speed: 357 km/sec Density: 3.4 p/cc Temp: 44900 K Bz: -3 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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