[Ips-dsgr] ASWFC Daily Report - 22 December 24 issued 2330 UT on 22 Dec 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Mon Dec 23 10:30:48 AEDT 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/22 DECEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 22 DECEMBER AND FORECAST FOR 23 DECEMBER - 25 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 22 Dec: R1
Flares Max Fadeout Freq. Sectors
M1.0 0410UT possible lower E. Asia/Aust.
M1.1 1414UT possible lower South American/
Atlantic
M1.1 2049UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 22 Dec: 223/173
1B. SOLAR FORECAST
23 Dec 24 Dec 25 Dec
Activity R0-R1, chance R2 R0-R1, chance R2 R0-R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 220/170 220/170 215/165
COMMENT: Solar activity on UT day 22-Dec was at the R1 level,
due to an M1.0 flare at 22/0410UT, an M1.1 flare at 22/1414UT
and an M1.1 flare at 22/2049UT. There are currently eight numbered
sunspot regions visible on the solar disk and one unnumbered
region. AR3932 (S17E48, beta) and AR3930 (S22W58, beta) were
responsible for the three M-class flares on 22-Dec, both of these
regions appeared stable over the UT-day, although a lack of imagery
makes growth difficult to analyse. AR3926 (S20W09, alpha), AR3928
(S17E39, beta-gamma) and AR3934 (N12E65, alpha) all showed spot
development over the UT day. An unnumbered region has recently
rotated onto the solar disk at around S18E72 with alpha magnetic
complexity. All other sunspot regions are stable. Solar activity
is expected to be at R0-R1 levels over 23-25 Dec, with a chance
of isolated R2 flares. S0 solar radiation storm conditions were
observed on UT day 22-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 23-Dec. S0 conditions,
with a chance of S1 are expected on 24-25 Dec. Multiple CMEs
were observed on 22-Dec, but none are considered significantly
geoeffective. A CME first observed on 21-Dec at 2000UT in SOHO
and STEREO-A imagery associated with a filament eruption in the
northeast quadrant of the disk has been further analysed. Modelling
suggests this CME presents the chance of a glancing impact with
Earth on 24-Dec at 0700UT +/- 12 hours. A large CME directed
to the southwest is visible in SOHO and STEREO-A imagery from
22/0400UT. This CME is associated with coronal movement off the
western limb. Modelling uncertainty was increased due to a lack
of available STEREO-A imagery. Modelling suggests this CME presents
the chance of a glancing impact with Earth on 24-Dec at 2000UT
+/- 12 hours. The solar wind speed was elevated over the UT day,
mostly ranging between 520 km/s and 750 km/s. The solar wind
speed is currently at around 580 km/s. The peak total interplanetary
field strength (IMF, Bt) was 9 nT and the north-south IMF component
(Bz) was +8 to -7 nT. The current enhancement in the solar wind
environment may be due to ongoing effects from a recent CME impact.
The solar wind speed is expected to continue to be elevated on
23-Dec. Slight enhancements are possible on 24-Dec due to the
chance of two glancing impacts from CMEs first observed on 21-Dec
and 22-Dec, although if wind speed remains at current levels
these enhancements may not be noticeable. The solar wind is expected
to remain elevated on 25-dec.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 22 Dec: G0
Estimated Indices 22 Dec : A K
Australian Region 12 22233333
Cocos Island 8 22123322
Darwin 9 12223323
Townsville 12 22233333
Learmonth 10 22223332
Alice Springs 11 12233333
Gingin 12 22233333
Canberra 12 22233333
Kennaook Cape Grim 14 23333333
Hobart 14 23333333
Estimated Antarctic Regional K Indices 22 Dec :
Macquarie Island 17 2234443-
Casey 35 46644333
Mawson 30 34444554
Observed Regional daily pc3 Indices 22 Dec :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 15 (Quiet)
Canberra 4 (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 22 Dec : A
Fredericksburg 9
Planetary 12
Observed AFr/Ap Indices 21 Dec : A K
Fredericksburg 13
Planetary 12 3312 3333
2B. MAGNETIC FORECAST
Date Ap Conditions
23 Dec 10 G0
24 Dec 16 G0, chance of G1
25 Dec 10 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 22-Dec. G2 conditions were observed at Casey
station whilst G1 conditions were observed at Mawson. G0 geomagnetic
conditions are expected on 23-Dec. G0 conditions with a chance
of G1 are expected on 24-Dec due to two possible glancing CME
impacts. G0 conditions are expected on 25-Dec.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
22 Dec Normal-fair Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
23 Dec Normal-fair Normal-fair Fair-poor
24 Dec Normal-fair Normal-fair Fair-poor
25 Dec Normal-fair Normal-fair Fair-poor
COMMENT: HF radio propagation conditions were fair at the start
and end of 21-Dec at low and mid latitudes, with poor conditions
observed at high latitudes at these times. Conditions were mostly
normal in the middle of the UT day. HF radio propagation conditions
are expected to be mostly normal to fair over 23-25 Dec, with
fair to poor conditions expected at high latitudes. Shortwave
fadeouts are possible.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
22 Dec 101
Observed Australian Regional MUFs
Cocos Island Region:
Mostly near predicted monthly values.
Depressed by 20% after local dawn.
Niue Island Region:
Mostly near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Depressed by 15% during local day.
Near predicted monthly values during local night.
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
23 Dec 110 Near predicted monthly values
24 Dec 100 Near predicted monthly values
25 Dec 110 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 22-Dec were mostly
near predicted monthly values, with depressions of up to 15%
observed in the southern Australian region during local day.
Mild spread F was observed at Hobart during local day. Sporadic
E was observed at Hobart during local dawn and at Brisbane and
Perth spread throughout the day. MUFs are expected to be mostly
near predicted monthly values over 23-25 Dec. Shortwave fadeouts
are possible.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 21 Dec
Daily Proton Fluence >1 MeV: 4.8E+05
Daily Proton Fluence >10 MeV: 2.1E+05
Daily Electron Fluence >2 MeV: 2.10E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C2.0
DSCOVR Satellite Solar Wind Day Averaged Data for 21 Dec
Speed: 508 km/sec Density: 2.8 p/cc Temp: 202000 K Bz: 2 nT
(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------
Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au
More information about the ips-dsgr
mailing list