[Ips-dsgr] ASWFC Daily Report - 10 September 24 issued 2330 UT on 10 Sep 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Sep 11 09:30:50 AEST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/10 SEPTEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 10 SEPTEMBER AND FORECAST FOR 11 SEPTEMBER - 13 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 10 Sep: R1
Flares Max Fadeout Freq. Sectors
M1.2 0018UT possible lower West Pacific
M1.6 1547UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 10 Sep: 205/156
1B. SOLAR FORECAST
11 Sep 12 Sep 13 Sep
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 205/156 200/152 200/152
COMMENT: Solar activity on UT day 10-Sep was at the R1 level
due to an M1.2 flare at 10/0028UT and an M1.6 flare at 10/1547UT.
There are currently eight numbered solar regions on the visible
solar disk. AR3811 (S10W67, beta), AR3813 (S22W41, beta-gamma),
AR3814 (N16W02, beta-delta) and AR3822 (N14E12, beta) all showed
spot development over the UT day. AR3814 was responsible for
the first M-class flare of the day, with the other flare occurring
over the western limb. AR3814 is the most significant sunspot
region currently visible on the solar disk due to its size and
complexity and will remain on the disk until 17-Sep. All other
regions are either stable or in decay. Solar activity is expected
to be at the R1 level over 11-13 Sep, with a chance of R2. S1
radiation storm conditions were observed from the beginning of
10-Sep until 10/0410UT when the >10MeV proton flux measured at
GOES dropped below the S1 threshold. The proton flux remained
elevated but in decline for the remainder of the UT day. S0 radiation
storm conditions are expected over 11-13 Sep, with a chance of
S1 on 11-Sep. Several CMEs were observed over the UT day. A north
directed partial halo CME is visible in SOHO and STEREO-A imagery
from 10/0036UT with STEREO-A imagery suggesting this CME is earth-directed.
An eruption on disk from 09/2348UT is visible at around N15E15
in SDO and GOES SUVI imagery associated with the M1.2 flare from
AR3814 at 10/0028UT. A small filament lift off is also visible
in H-Alpha imagery from 10/0026UT at around N10E15. These events
are all considered to be associated and modelling suggests this
CME is geoeffective with an impact expected at 12-Sep 2200UT
+/- 12 hours. All other CMEs observed on 10-Sep are not considered
geoeffective. The solar wind speed on UT day 10-Sep was steady
ranging from 365 to 490 km/s and is currently near 400 km/s.
The peak total interplanetary field strength (IMF, Bt) was 9
nT and the north-south IMF component (Bz) range was +8 to -4
nT. An increase in solar wind speed is expected in the early
hours of 11-Sep due to an anticipated impact from a CME first
observed on 08-Sep. Following this, the solar wind speed is expected
to decline over most of 12-Sep, before another increase late
on 12-Sep or early on 13-Sep, due to an anticipated impact from
a CME first observed on 10-Sep.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 10 Sep: G0
Estimated Indices 10 Sep : A K
Australian Region 6 23211022
Cocos Island 6 14210021
Darwin 8 33211032
Townsville 10 34212132
Learmonth 7 32211032
Alice Springs 10 25211022
Gingin 3 1211002-
Canberra 6 33111022
Kennaook Cape Grim 4 22102022
Hobart 4 22102022
Estimated Antarctic Regional K Indices 10 Sep :
Macquarie Island 2 02011011
Casey 13 34421132
Mawson 13 43320134
Observed Regional daily pc3 Indices 10 Sep :
Darwin 15 (Quiet)
Townsville 17 (Quiet)
Learmonth 17 (Quiet)
Alice Springs 21 (Quiet to unsettled)
Gingin 4 (Quiet)
Canberra 18 (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 10 Sep : A
Fredericksburg 14
Planetary 18
Observed AFr/Ap Indices 09 Sep : A K
Fredericksburg 9
Planetary 9 2122 1333
2B. MAGNETIC FORECAST
Date Ap Conditions
11 Sep 22 G1, chance of G2
12 Sep 15 Chance of G1
13 Sep 30 G1 - G2
COMMENT: ASWFC Geomagnetic Warning 49 was issued on 9 September
and is current for 10-11 Sep. Mostly G0 geomagnetic conditions
were observed in the Australian region on UT day 10-Sep, with
an isolated period of G1 observed at Alice Springs. G0 conditions
were observed in the Antarctic region on 10-Sep. G1 geomagnetic
conditions are expected on 11-Sep, with a chance of G2, due to
an anticipated impact from a CME first observed on 08-Sep. There
is a chance of G1 on 12-Sep as CME effects wane and the chance
of an early impact from a CME first observed on 10-Sep. G1-G2
conditions are expected on 13-Sep due to an anticipated impact
from the CME just mentioned.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
10 Sep Normal Normal Normal-fair
PCA Event : 10MeV Proton/PCA Event Began at 1625UT 09/09, Ended at 0410UT 10/09
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
11 Sep Normal Normal-fair Fair
12 Sep Normal Normal Normal-fair
13 Sep Fair Fair Fair-poor
COMMENT: HF radio communication conditions on UT day 10-Sep were
mostly normal. Increased absorption may have been experienced
at high latitudes in the early hours of the day due to S1 solar
radiation conditions. Mildly degraded conditions are expected
for middle to high latitudes on 11-13 Sep due to an expected
increase in geomagnetic activity over this period, stronger degradations
are expected at higher latitudes. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
10 Sep 166
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 35% during local day.
Enhanced by 90% during local night.
Niue Island Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Enhanced by 20% after local dawn.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 25% during local night.
Southern Australian Region:
Enhanced by 20% during local day.
Enhanced by 30% during local night.
Enhanced by 30% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Aug 159
Sep 117
Oct 116
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
11 Sep 160 Near to 15% above predicted monthly values
12 Sep 140 Near to 15% above predicted monthly values
13 Sep 130 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 99 was issued on
9 September and is current for 9-11 Sep. Maximum usable frequencies
(MUFs) in the Australian region on UT day 10-Sep were near predicted
monthly values to 30% enhanced, with the strongest enhancements
observed during local night. Ionospheric scintillation was observed
at multiple locations over the interval 10/0918-1348UT. Spread
F was observed during local night hours at Darwin and Cocos Islands.
MUFs are expected to be near predicted monthly values to enhanced
by 20% until anticipated geomagnetic activity occurs on 11-Sep.
Following geomagnetic activity MUFs are expected to be near monthly
predicted values with the chance of degradations at higher latitudes.
MUFs are expected to recover over 12-Sep until further geomagnetic
activity late on 12-Sep or early on 13-Sep when degradations
are again possible. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 09 Sep
Daily Proton Fluence >1 MeV: 5.4E+07
Daily Proton Fluence >10 MeV: 8.0E+05
Daily Electron Fluence >2 MeV: 1.30E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C3.0
DSCOVR Satellite Solar Wind Day Averaged Data for 09 Sep
Speed: 388 km/sec Density: 1.7 p/cc Temp: 120000 K Bz: 2 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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