[Ips-dsgr] ASWFC Daily Report - 24 December 23 issued 2330 UT on 24 Dec 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Mon Dec 25 10:30:09 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/24 DECEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 24 DECEMBER AND FORECAST FOR 25 DECEMBER - 27 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 24 Dec: R1
Flares Max Fadeout Freq. Sectors
M2.9 1118UT possible lower European
M2.6 1649UT possible lower South American/
Atlantic
M1.1 1951UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 24 Dec: 183/136
1B. SOLAR FORECAST
25 Dec 26 Dec 27 Dec
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 180/133 170/124 165/119
COMMENT: Solar activity on UT day 24-Dec was at the R1 level
due to an M2.9 flare at 24/1118UT, an M2.6 flare at 24/1649UT
and an M1.1 flare at 24/1951UT. There are currently seven numbered
sunspot regions visible on the solar disk. AR3530 (N09W02, beta-delta)
displayed significant development over the UT day, although it
is yet to produce any significant flaring. The largest two M-class
flares of the day were produced by AR3529 (S20W24, beta). This
is the largest sunspot region visible on the solar disk and displayed
some decay in its trailer spots over the UT day. The M1.1 flare
was produced by an active region off the eastern limb. AR3531
(S20E17, beta) also developed on 24-Dec, but is small, simple
and has no history of flaring. All other sunspot regions are
either stable or in decay. Solar activity is expected to be at
R0-R1 levels over 25-27 Dec. A large filament extending from
around N56W07 to N20W50 lifted off the solar disk from 24/1016UT,
predominantly directed to the north. This event is visible in
SDO, GOES SUVI and H-Alpha imagery. This liftoff produced a slow,
partial halo CME directed to the north, visible from 24/1212UT
in SOHO and STEREO-A imagery. Modelling indicates there is a
chance of a glancing impact from this CME on 27-Dec at 1700UT
+/- 12 hours. A southwest directed CME is visible in SOHO and
STEREO-A imagery from 24/1709UT. A filament lift off is visible
in SDO, GOES SUVI and H-Alpha imagery from 24/1441UT at around
S20W45. Modelling indicates this CME will impact Earth on 28-Dec
at 0200UT +/- 12 hours. An eruption off the eastern limb at around
N35 is visible in SDO, GOES SUVI and H-Alpha imagery from 24/1608UT.
An associated, east directed CME is visible in SOHO and STEREO-A
imagery from 24/1723UT. This CME is not considered to be geoeffective.
An eruption is visible of the southeast limb at around S20 from
24/1924UT in SDO, GOES SUVI and H-Alpha imagery. This eruption
is associated with the M1.1 flare at 24/1951UT. No CME associated
with this eruption is visible in available imagery, given the
location and direction of this event, any associated CME is unlikely
to be geoeffective. The solar wind speed on UT day 24-Dec was
steady, ranging from 366 to 468 km/s and is currently near 390
km/s. The peak total interplanetary field strength (IMF, Bt)
was 9 nT and the north south IMF component (Bz) range was +7
to -7 nT. A sustained period of mostly negative Bz was observed
from 24/0142UT to 24/1033UT. The solar wind speed is expected
to continue to remain at background levels over 25-27 Dec, an
increase is possible late in the day on 27-Dec, due to a possible
glancing impact from a CME first observed on 24-Dec.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 24 Dec: G0
Estimated Indices 24 Dec : A K
Australian Region 6 22221221
Cocos Island 3 11121210
Darwin 5 21221211
Townsville 6 12221222
Learmonth 5 21221221
Alice Springs 5 21221221
Gingin 6 22222221
Canberra 5 12221121
Hobart 8 12332221
Estimated Antarctic Regional K Indices 24 Dec :
Macquarie Island 10 13343110
Casey 15 34432322
Mawson 20 45432323
Observed Regional daily pc3 Indices 24 Dec :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 6 (Quiet)
Hobart 8 (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 24 Dec : A
Fredericksburg 9
Planetary 10
Observed AFr/Ap Indices 23 Dec : A K
Fredericksburg 5
Planetary 6 0020 2311
2B. MAGNETIC FORECAST
Date Ap Conditions
25 Dec 5 G0
26 Dec 5 G0
27 Dec 14 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 24-Dec. Mostly G0 conditions were observed in
the Antarctic region, with an isolated period of G1 observed
at Mawson. G0 geomagnetic conditions are expected over 25-26
Dec. G0 conditions with a chance of G1 are expected on 27-Dec,
due to a possible glancing impact from a CME first observed on
24-Dec.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
24 Dec Normal-fair Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
25 Dec Normal Normal Normal
26 Dec Normal Normal Normal
27 Dec Normal Normal Normal-fair
COMMENT: HF radio communication conditions on UT day 24-Dec were
normal to fair for the first half of the day, with fair conditions
mostly at low and high latitudes. Mostly normal conditions were
observed at all latitudes for the second half of the day. Mostly
normal conditions are expected over 25-27 Dec. Shortwave fadeouts
are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
24 Dec 126
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 35% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Nov 114
Dec 100
Jan 98
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
25 Dec 115 Near predicted monthly values
26 Dec 115 Near predicted monthly values
27 Dec 115 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 133 was issued on
24 December and is current for 24-26 Dec. Maximum usable frequencies
(MUFs) on UT day 24-Dec in the Australian region were near predicted
monthly values, with enhancements of up to 15% observed in the
northern Australian region during local day. Sporadic E obscured
the foF2 at Canberra at times between 24/0300UT and 24/0900UT.
MUFs are expected to be near predicted monthly values over 25-27
Dec, with the possibility of further periods of sporadic E. Shortwave
fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 23 Dec
Daily Proton Fluence >1 MeV: 4.4E+04
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 4.00E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 6%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 23 Dec
Speed: 344 km/sec Density: 3.1 p/cc Temp: 46100 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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