[Ips-dsgr] ASWFC Daily Report - 26 October 24 issued 2338 UT on 26 Oct 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Oct 27 10:38:57 AEDT 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 OCTOBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 OCTOBER AND FORECAST FOR 27 OCTOBER - 29 OCTOBER
STATUS INDICATORS SOL:** RED ** MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 Oct: R3
Flares Max Fadeout Freq. Sectors
M9.5 0623UT probable lower Mid East/Indian
X1.8 0722UT probable all Mid East/Indian
M2.2 1150UT possible lower European
M2.8 1206UT possible lower European
M1.6 1416UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Oct: 238/187
1B. SOLAR FORECAST
27 Oct 28 Oct 29 Oct
Activity R2-R3 R2-R3 R2-R3
Fadeouts Probable Probable Probable
10.7cm/SSN 240/189 245/195 245/195
COMMENT: Solar activity on UT day 26-Oct was R3 due an X1.8 flare
from solar region AR3873 (S08E50, beta-gamma). This flare had
two peaks and was preceded by an M9.5 flare at 26/0623UT from
the same region. Three R1 class flares were also observed, two
were from a new region behind the northeast solar limb (N18)
and the M1.6 was from AR3872 ( S13E42, beta-gamma-delta). Solar
region AR3873 penumbra has declined slightly and AR3872 has been
mostly stable. Solar region AR3869 (S13E25, beta-gamma) intermediate
spots are slightly growing. These three regions located in the
southeast solar quadrant are currently the most significant on
the solar disk. Smaller solar regions AR3874 (N27E11, beta-gamma)
and AR3876 (S01E24, beta) are both growing. There are currently
eleven numbered sunspot regions on the solar disk. Other sunspot
regions are generally stable. Solar activity is expected to be
R2-R3 over 27-29 Oct. S1 solar radiation storm conditions were
observed from 26/1850UT following the X1.8 flare and remains
in progress. S1 solar radiation conditions are expected for 27-Oct
with S0 conditions on 28-29 Oct with a general increasing event
risk of further events. An asymmetric halo CME directed to the
southeast was observed in association with the X1.8 flare. The
analysis of the CME event considered both the central bulk of
the CME and the CME outer envelope, resulting in a shock arrival
window of 27/2100UT to 28/0400UT. The later arrival time is from
the bulk/centre of the CME and this model run shows a much weaker
impact than the outer envelope interpretation which is the earlier
arrival time and a much stronger impact. Both interpretations
show the bulk of the CME crossing the Earth's orbit behind and
below the Earth, with the degree of the top and one side of the
CME interacting with the Earth's magnetosphere the main difference.
The solar wind environment on UT day 26-Oct was initially slow
and steady with a weak indistinct shock observed at 26/1533UT.
The solar wind speed ranged from 299 to near 490 km/s and is
currently near 430 km/s. The peak total interplanetary field
strength (IMF, Bt) was 22 nT and the north-south IMF component
range (Bz) was +20 to -19 nT. The IMF Bt became enhanced post
shock arrival and the IMF Bz component fluctuated rapidly. The
solar wind speed is expected to again be enhanced from late 27-Oct
to 28-Oct due to another CME glancing blow from the X1.8 flare.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 26 Oct: G0
Estimated Indices 26 Oct : A K
Australian Region 11 11212434
Cocos Island 8 11212333
Darwin 11 21213334
Townsville 17 21223445
Learmonth 16 21223534
Alice Springs 13 22213434
Gingin 11 11212434
Canberra 11 11212344
Kennaook Cape Grim 9 11112334
Hobart 10 11212334
Estimated Antarctic Regional K Indices 26 Oct :
Macquarie Island 9 10123333
Casey 20 43432344
Mawson 22 33223455
Observed Regional daily pc3 Indices 26 Oct :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 20 (Quiet)
Canberra 14 (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 26 Oct : A
Fredericksburg 11
Planetary 15
Observed AFr/Ap Indices 25 Oct : A K
Fredericksburg 2
Planetary 2 1000 1011
2B. MAGNETIC FORECAST
Date Ap Conditions
27 Oct 25 Initially G0 then G1-G2 later in UT day.
28 Oct 45 G1-G2, then declining to G0
29 Oct 12 G0
COMMENT: ASWFC Geomagnetic Warning 71 was issued on 24 October
and is current for 26-27 Oct. G0 geomagnetic conditions were
observed in the Australian on UT day 26-Oct. G0-G1 conditions
were observed in the Antarctic region. The induced geomagnetic
activity from the anticipated CME arrival was less than expected,
with a weak impulse in the geomagnetic field observed at 26/1619UT
followed by a mild increase in geomagnetic activity. Another
CME glancing blow arrival is expected from late 27-Oct to early
28-Oct in association with the X1.8 flare.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
26 Oct Normal Normal Fair-poor(PCA)
PCA Event : 10MeV Proton/PCA Event Began 26 10 2024 1850UT and is in progress
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
27 Oct Normal Normal-fair Poor(PCA)
28 Oct Normal Fair Poor
29 Oct Normal Fair-normal Poor-fair
COMMENT: HF radio communication conditions on UT day 26-Oct were
mostly normal. Casey and Davis riometers observed a mild increase
in absorption of approximately 0.5 to 1dB late in the UT day
on 26-Oct in association with the S1 solar radiation storm. Due
to the induced geomagnetic activity being milder than forecast
the degraded HF conditions are now not expected for 27-Oct for
middle latitude locations. Degraded HF conditions are expected
on 28-Oct due to anticipated geomagnetic activity from another
CME. Shortwave fadeouts probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
26 Oct 154
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Enhanced by 20% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 35% during local night.
Enhanced by 25% after local dawn.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Proton event in progress, increased absorption observed.
Monthly T index:
Month T index
Sep 147
Oct 116
Nov 115
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
27 Oct 145 Near predicted monthly values to 20% enhanced.
28 Oct 90 Depressed 15 to 20%/near predicted monthly values
29 Oct 100 Depressed 10 to 15%/near predicted monthly values
COMMENT: ASWFC Preliminary HF Communications Warning 121 was
issued on 24 October and is current for 26-27 Oct. ASWFC SWF
HF Communications Warning 122 was issued on 26 October and is
current for 26-28 Oct. Maximum usable frequencies (MUFs) in the
Australian region on UT day 26-Oct were near predicted values
to 35% enhanced. Strong enhancements were observed during local
night hours at Darwin. Spread F was observed during local night
hours at Hobart. Equatorial scintillation was observed at Darwin
during the interval 26/1116-1410UT. A shortwave fadeout impacting
only the lower HF frequencies was observed in the northwest Australian
region (Darwin and Learmonth) during the approximate interval
26/0615-0720UT. Due to weaker overnight geomagnetic activity
depressed conditions are now not expected for the southern Australian
region on 27-Oct. MUFs are expected to be near normal to 20%
enhanced on 27-Oct. MUFs may become 15-20% depressed in the southern
Australian region on 28-Oct and possibly into 29-Oct due to anticipated
geomagnetic activity from another partially Earth directed CME.
Shortwave fadeouts are probable.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 25 Oct
Daily Proton Fluence >1 MeV: 4.7E+05
Daily Proton Fluence >10 MeV: 2.9E+04
Daily Electron Fluence >2 MeV: 1.70E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.8
DSCOVR Satellite Solar Wind Day Averaged Data for 25 Oct
Speed: 319 km/sec Density: 3.6 p/cc Temp: 40900 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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