[Ips-dsgr] ASWFC Daily Report - 15 December 23 issued 2330 UT on 15 Dec 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sat Dec 16 10:30:59 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/15 DECEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 15 DECEMBER AND FORECAST FOR 16 DECEMBER - 18 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 15 Dec: R2
Flares Max Fadeout Freq. Sectors
M6.3 0715UT probable lower Mid East/Indian
M6.9 0734UT probable lower Mid East/Indian
Observed 10.7 cm flux/Equivalent Sunspot Number for 15 Dec: 144/98
1B. SOLAR FORECAST
16 Dec 17 Dec 18 Dec
Activity R1-R2 R1-R2 R1-R2
Fadeouts Possible Possible Possible
10.7cm/SSN 145/99 145/99 140/94
COMMENT: Solar activity on UT day 15-Dec was at the R2 level,
due to an M6.9 flare at 15/0734UT from AR3514 (N05W65, beta-gamma-delta).
There are currently nine numbered sunspot regions visible on
the solar disk and one unnumbered region. AR3514 is the most
magnetically complex region on the solar disk and has shown significant
decay over the UT day. AR3519 (S10E11, beta-gamma) has exhibited
spot development over the 24-hour period, particularly in its
intermediate spots. Newly numbered AR3521 (N12E72, alpha) recently
rotated over the eastern limb and is stable. An unnumbered region
is visible near N01E44 (beta) and has shown minor growth since
appearing on the solar disk. All other sunspot regions are either
stable or in decay. Solar activity is expected to be at R1-R2
levels over 16-18 Dec. The solar proton flux increased over UT
day 15-Dec, although remained at the S0 level. S1 solar proton
conditions are expected over 16-18 Dec. A west directed CME was
observed, visible in LASCO C2 and STEREO-A coronagraph imagery
from 15/0748UT. This CME is associated with the aforementioned
M6.9 flare from AR3514. Modelling indicates this CME does not
contain a geoeffective component. A filament eruption was observed,
visible in H-alpha imagery near S18W07 at 15/2055UT. At this
stage no associated CME has been observed. No other Earth-directed
CMEs have been observed. The solar wind speed on UT day 15-Dec
increased, ranging from 280 to 520 km/s and is currently near
500 km/s. The peak total interplanetary field strength (IMF,
Bt) was 23 nT and the north south IMF component (Bz) range was
+18 to -13 nT. A solar wind shock was observed at 15/1058UT,
indicative of a CME arrival. Several short periods of southward
IMF conditions were observed following the CME arrival. The solar
wind speed is expected to remain elevated over 16-18 Dec. A moderate
sized northern hemisphere coronal hole is currently crossing
the central meridian and may influence the solar wind speed on
18-Dec.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 15 Dec: G0
Estimated Indices 15 Dec : A K
Australian Region 13 11144333
Cocos Island 10 11233332
Darwin 13 11144333
Townsville 16 11154333
Learmonth 18 11254433
Alice Springs 13 11144333
Gingin 12 20233343
Canberra 10 11043323
Hobart 12 11143333
Estimated Antarctic Regional K Indices 15 Dec :
Macquarie Island 17 10155422
Casey 21 34344433
Mawson 21 32235353
Observed Regional daily pc3 Indices 15 Dec :
Darwin 2 (Quiet)
Townsville 3 (Quiet)
Learmonth 4 (Quiet)
Alice Springs 6 (Quiet)
Gingin 7 (Quiet)
Canberra 5 (Quiet)
Hobart 13 (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 15 Dec : A
Fredericksburg 11
Planetary 12
Observed AFr/Ap Indices 14 Dec : A K
Fredericksburg 13
Planetary 13 3334 2212
2B. MAGNETIC FORECAST
Date Ap Conditions
16 Dec 16 G0, chance G1
17 Dec 35 G1, chance G2
18 Dec 12 G0
COMMENT: ASWFC Geomagnetic Warning 79 was issued on 15 December
and is current for 17 Dec only. G0 geomagnetic conditions were
observed in the Australian region on UT day 15-Dec. G0-G1 geomagnetic
conditions were observed in the Antarctic region. G0 geomagnetic
conditions are expected on 16-Dec, with a chance of G1 due to
a weak CME arrival. G1 geomagnetic conditions, with a chance
of G2 are expected on 17-Dec due to component arrival of CMEs
observed on 14-Dec. G0 geomagnetic conditions are expected on
18-Dec.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
15 Dec Normal Normal-fair Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
16 Dec Normal Normal-fair Fair
17 Dec Fair Fair Fair-poor
18 Dec Normal Normal Normal-fair
COMMENT: HF radio communication conditions on UT day 15-Dec were
mostly normal, with some fair conditions observed at mid to high
latitudes. Mostly normal HF communication conditions are expected
on 16-Dec. A mild degradation for middle to high latitudes is
possible on 16-Dec due to a weak CME, with further degraded conditions
expected over 17-18 Dec due to the anticipated arrivals of CMEs
observed on 14-Dec. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
15 Dec 82
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Depressed by 20% during local day.
Near predicted monthly values during local night.
Depressed by 20% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% 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
16 Dec 100 Near predicted monthly values
17 Dec 70 Near predicted monthly values/depressed 15 to
30%
18 Dec 80 Near predicted monthly values/depressed 0 to
15%
COMMENT: ASWFC SWF HF Communications Warning 129 was issued on
14 December and is current for 14-16 Dec. ASWFC Preliminary HF
Communications Warning 130 was issued on 15 December and is current
for 17-18 Dec. Maximum usable frequencies (MUFs) were near predicted
monthly values to 20% depressed in the Australian region on UT
day 15-Dec. MUFs are expected to be near predicted monthly values
over 16-18 Dec, with mildly degraded HF conditions possible for
the southern Australian region during local night hours on 16-Dec
due to an anticipated weak CME arrival. A further degradation
in ionospheric conditions is expected for the southern Australian
region over 17-18 Dec due to anticipated component arrivals of
CME activity observed on 14-Dec. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 14 Dec
Daily Proton Fluence >1 MeV: 1.4E+05
Daily Proton Fluence >10 MeV: 2.2E+04
Daily Electron Fluence >2 MeV: 1.20E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.4
DSCOVR Satellite Solar Wind Day Averaged Data for 14 Dec
Speed: 344 km/sec Density: 2.9 p/cc Temp: 62400 K Bz: -6 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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