[Ips-dsgr] ASWFC Daily Report - 21 December 24 issued 2330 UT on 21 Dec 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Dec 22 10:30:49 AEDT 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 DECEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 21 DECEMBER AND FORECAST FOR 22 DECEMBER - 24 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 21 Dec: R1
Flares Max Fadeout Freq. Sectors
M1.9 0039UT possible lower West Pacific
Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Dec: 195/147
1B. SOLAR FORECAST
22 Dec 23 Dec 24 Dec
Activity R0-R1, chance R2 R0-R1, chance R2 R0-R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 190/143 190/143 190/143
COMMENT: Solar activity on UT day 21-Dec was at the R1 level,
due to an M1.9 flare at 21/0039UT. There are currently nine numbered
sunspot regions visible on the disk. Newly numbered region AR3932
(S18E41, beta) was responsible for the only M-class flare of
the UT day and appears stable. AR3928 (S17E38, beta-gamma), AR3930
(S20W57, beta) and AR3934 (N12E65, alpha) all showed spot development
on 21-Dec. AR3927 (S11E33, beta-gamma) and AR3928 are the most
magnetically complex regions on the solar disk. All other sunspot
regions are either stable or in decline. Solar activity is expected
to be at R0-R1 levels over 22-24 Dec, with a chance of isolated
R2 flares. S0 solar radiation storm conditions were observed
on UT day 21-Dec, however the >10MeV proton flux as measured
at GOES is elevated just below the S1 threshold. S0-S1 solar
radiation storm conditions are expected on 22-Dec. S0 conditions,
with a chance of S1 are expected on 23-24 Dec. Multiple CMEs
were observed on 21-Dec, but none are considered geoeffective.
A large filament eruption is visible in GOES SUVI and H-Alpha
imagery from 21/1945UT at around N35 on the east limb. This eruption
has an associated CME visible from 21/2000UT in SOHO imagery.
There is not enough imagery to fully analyse this CME yet, further
analysis will be performed once more imagery becomes available.
This CME is not expected to be geoeffective based on the location
and direction of the eruption. The solar wind speed increased
over the UT day, ranging between 440 km/s and 600 km/s. The solar
wind speed is currently at around 570 km/s. The peak total interplanetary
field strength (IMF, Bt) was 9 nT and the north-south IMF component
(Bz) was +8 to -8 nT. The current enhancement in the solar wind
environment may be due to ongoing effects from a recent CME impact.
The solar wind is expected to be elevated over 22-23 Dec, with
a decline towards background levels possible over 23-24 Dec.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 21 Dec: G0
Estimated Indices 21 Dec : A K
Australian Region 12 32232333
Cocos Island 7 21222232
Darwin 8 22122233
Townsville 13 32233333
Learmonth 12 31233333
Alice Springs 11 22232333
Gingin 13 32233333
Canberra 11 22232333
Kennaook Cape Grim 13 32332333
Hobart 13 32332333
Estimated Antarctic Regional K Indices 21 Dec :
Macquarie Island 11 22224233
Casey 40 55654344
Mawson 36 54444464
Observed Regional daily pc3 Indices 21 Dec :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 12 (Quiet)
Canberra 2 (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 21 Dec : A
Fredericksburg 11
Planetary 14
Observed AFr/Ap Indices 20 Dec : A K
Fredericksburg 10
Planetary 11 3201 3332
2B. MAGNETIC FORECAST
Date Ap Conditions
22 Dec 10 G0
23 Dec 8 G0
24 Dec 5 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 21-Dec. G2 conditions were observed in the Antarctic
region. G0 geomagnetic conditions are expected over 22-24 Dec.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
21 Dec Normal-fair Normal-fair Fair-poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
22 Dec Normal-fair Normal-fair Fair-poor
23 Dec Normal-fair Normal-fair Fair-poor
24 Dec Normal-fair Normal-fair Fair-poor
COMMENT: HF radio propagation conditions were mildly degraded
at the start and end of 21-Dec, with poor conditions observed
at high latitudes at these times. HF radio propagation conditions
are expected to be mostly normal to fair over 22-24 Dec, with
fair to poor conditions expected at high latitudes. Shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
21 Dec 127
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Mostly near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Nov 127
Dec 117
Jan 114
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
22 Dec 120 Near predicted monthly values
23 Dec 120 Near predicted monthly values
24 Dec 120 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 147 was issued on
21 December and is current for 21-23 Dec. Maximum usable frequencies
(MUFs) in the Australian region on UT day 21-Dec were mostly
near predicted monthly values. Mild spread F was observed at
Hobart during local night. MUFs are expected to be near predicted
monthly values over 22-24 Dec. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 20 Dec
Daily Proton Fluence >1 MeV: 2.4E+05
Daily Proton Fluence >10 MeV: 2.8E+04
Daily Electron Fluence >2 MeV: 1.00E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.6
DSCOVR Satellite Solar Wind Day Averaged Data for 20 Dec
Speed: 469 km/sec Density: 2.6 p/cc Temp: 126000 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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