[Ips-dsgr] ASWFC Daily Report - 19 December 23 issued 2330 UT on 19 Dec 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Wed Dec 20 10:30:08 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 DECEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 DECEMBER AND FORECAST FOR 20 DECEMBER - 22 DECEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Dec: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Dec: 179/132
1B. SOLAR FORECAST
20 Dec 21 Dec 22 Dec
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 180/133 178/131 178/131
COMMENT: Solar activity on UT day 19-Dec was at the R0 level.
Solar regions AR3528(N09E03, beta-delta) and AR3529(S20E44, beta)
produced C class flares. Both these regions are currently growing.
Solar regions AR3519(S10W39, beta), AR3526(N15E46, beta) and
AR3530(N09E68, beta) are also growing though have been flare
quiet. There are currently ten numbered regions on the solar
disk. All other sunspot regions are small and mostly stable.
Solar activity is expected to be at R0-R1 levels over 20-22 Dec.
In GONG H-alpha imagery a solar filament in the south east solar
quadrant centred at S20E25 appears to have partially lifted off
over an extended period 18/22UT to 19/05UT. Another filament
nearby centred at S10E38 also appears unstable. The long solar
filament in the north east solar quadrant centred at N40E22 now
appears more segmented and is perhaps becoming less stable. No
Earth directed CMEs were observed. A very faint minor south east
CME is visible in LASCO C2 difference imagery from 19/0812UT
possibly associated with the minor slow south east partial filament
lift off. The solar wind speed observed by the ACE satellite,
on UT day 19-Dec was elevated with a decreasing trend, ranging
from 600 to 704 km/s and is currently near 589km/s. The peak
total interplanetary field strength (IMF, Bt) was 9 nT and the
north south IMF component (Bz) range was +6 to -7 nT. The solar
wind speed is expected to remain elevated over 20-21 Dec with
a declining trend due to waning coronal hole wind stream effects.
Another isolated coronal hole is across the solar central meridian
in the southern solar hemisphere centred at S25W10 and may moderately
increase solar wind speeds 24-25 Dec. There is some activity
on the south east solar limb at solar latitude S20, possibly
indicating the return of old solar region AR3500, but at this
stage it does not appear that significant.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 19 Dec: G0
Estimated Indices 19 Dec : A K
Australian Region 9 33321122
Cocos Island 5 32211111
Darwin 8 33311112
Townsville 9 33321122
Learmonth 10 33322222
Alice Springs 9 33321212
Gingin 9 33321222
Canberra 8 33311122
Hobart 8 33311122
Estimated Antarctic Regional K Indices 19 Dec :
Macquarie Island 9 33311222
Casey 34 56633233
Mawson 30 55443425
Observed Regional daily pc3 Indices 19 Dec :
Darwin 22 (Quiet to unsettled)
Townsville 0 (Quiet)
Learmonth 4 (Quiet)
Alice Springs 0 (Quiet)
Gingin 41 (Unsettled)
Canberra 47 (Unsettled)
Hobart 65 (Active)
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 19 Dec : A
Fredericksburg 12
Planetary 16
Observed AFr/Ap Indices 18 Dec : A K
Fredericksburg 16
Planetary 20 2354 4324
2B. MAGNETIC FORECAST
Date Ap Conditions
20 Dec 10 G0
21 Dec 10 G0
22 Dec 8 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 19-Dec. In the Antarctic region G2 geomagnetic
conditions were observed at Casey, G1 conditions at Mawson and
G0 conditions at Macquarie Island. G0 geomagnetic conditions
are expected over 20-22 Dec.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 Dec Normal Fair-normal Fair-normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 Dec Normal Normal Normal-fair
21 Dec Normal Normal Normal-fair
22 Dec Normal Normal Normal-fair
COMMENT: HF radio communication conditions on UT day 19-Dec were
fair to normal. Normal conditions are expected over 20-22 Dec.
Isolated shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 Dec 91
Observed Australian Regional MUFs
Cocos Island Region:
Mostly near predicted monthly values.
Depressed by 20% after local dawn.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 15% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
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 114
Dec 100
Jan 98
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
20 Dec 100 Near predicted monthly values
21 Dec 100 Near predicted monthly values
22 Dec 100 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 19-Dec in
the Australian region were generally depressed 15% to near predicted
monthly values. Sporadic E was observed at Townsville, Canberra
and Hobart. MUFs are generally expected to be near predicted
monthly values for 20-22 Dec. Isolated shortwave fadeouts are
possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 Dec
Daily Proton Fluence >1 MeV: 1.0E+06
Daily Proton Fluence >10 MeV: 1.8E+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: C1.6
DSCOVR Satellite Solar Wind Day Averaged Data for 18 Dec
Speed: 472 km/sec Density: 8.7 p/cc Temp: 74800 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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