[Ips-dsgr] ASWFC Daily Report - 02 September 23 issued 2333 UT on 02 Sep 2023 [SEC=OFFICIAL]
rwc
rwc at ips.gov.au
Sun Sep 3 09:33:19 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/02 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 02 SEPTEMBER AND FORECAST FOR 03 SEPTEMBER - 05 SEPTEMBER
STATUS INDICATORS SOL:GREEN MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 02 Sep: R1
Flares Max Fadeout Freq. Sectors
M3.3 0713UT possible lower Mid East/Indian
Observed 10.7 cm flux/Equivalent Sunspot Number for 02 Sep: 131/85
1B. SOLAR FORECAST
03 Sep 04 Sep 05 Sep
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 135/89 130/84 135/89
COMMENT: Solar activity on UT day 02-Sep was R1, due to a long
duration M3.3 flare from solar region AR3413(N09W83, beta). This
region showed signs of decay as it rotated off disk. There are
currently 5 small regions on the solar disk which are either
stable or in decay. An new small region has appeared in the north
west solar quadrant. A west directed semi halo CME was associated
with the M3 event, however due to the regions far western solar
longitude location at the time of the flare subsequent modelling
shows an Earth miss. No new significantly Earth directed CMEs
were observed on 02-Sep. A small solar filament located at N30W40
may have erupted at 02/1805UT (GONG H-alpha). Coronagraph imagery
will be checked as it becomes available for any associated CME.
The solar wind speed on UT day 02-Sep was elevated at approximately
500-600km/sec using data from the DSCOVR satellite, whilst the
ACE satellite shows peaks solar wind speeds of around 700km/sec
on 02-Sep. The DSCOVR solar wind parameters are very noisy, showing
increased speed and decreasing density indicating the Earth had
entered a coronal hole wind stream. This wind stream is likely
to have originated from a small narrow coronal hole which was
at solar central meridian at solar latitude N30 on 28-Aug. The
peak total interplanetary field strength (IMF, Bt) was 10 nT
and the north-south IMF component (Bz) range was +5 to -9 nT.
The IMF Bz component was frequently orientated mildly southward
during the UT day. At this stage a solar wind shock arrival remains
expected on 03-Sep due to a CME observed late on 30-Aug associated
with a solar filament eruption. The ACE EMPAM low energy ion
CME precursor channel does show an increasing trend, though it
now appears to be flattening out, if this recent trend continues
it may indicate that any shock arrival may be weaker than expected.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 02 Sep: G1
Estimated Indices 02 Sep : A K
Australian Region 24 33455333
Cocos Island 16 33334333
Darwin 23 33355333
Townsville 26 34455333
Learmonth 26 34455333
Alice Springs 24 33455333
Gingin 24 33455333
Canberra 22 33454333
Hobart 32 33565343
Estimated Antarctic Regional K Indices 02 Sep :
Macquarie Island 60 23776544
Casey 20 34434234
Mawson 79 47554486
Observed Regional daily pc3 Indices 02 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 26 (Quiet to unsettled)
Canberra 42 (Unsettled)
Hobart 61 (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 02 Sep : A
Fredericksburg 25
Planetary 36
Observed AFr/Ap Indices 01 Sep : A K
Fredericksburg 15
Planetary 12 3333 3232
2B. MAGNETIC FORECAST
Date Ap Conditions
03 Sep 30 G1, chance G2
04 Sep 18 G0-G1
05 Sep 12 G0
COMMENT: ASWFC Geomagnetic Warning 48 was issued on 1 September
and is current for 2-4 Sep. G1 geomagnetic conditions were observed
in the Australian region on UT day 01-Sep. In the Antarctic region
G2-G3 conditions were observed at Macquarie Island, G2-G4 conditions
were observed at Mawson, and G0 conditions were observed at Casey.
This geomagnetic activity is associated with a coronal hole wind
stream. The anticipated CME induced activity is yet to arrive,
though may now be weaker than originally expected. G1-G2 geomagnetic
conditions are expected on 03-Sep, due to an anticipated impact
from a CME.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
02 Sep Normal Normal-fair Fair-poor
PCA Event : 10MeV Proton/PCA Event Began at 0425UT 01/09, Ended at 2000UT 01/09
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
03 Sep Fair Fair Fair-poor
04 Sep Normal Normal-fair Fair
05 Sep Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 02-Sep were
degraded at mid to high latitudes. Degraded conditions are again
expected on 03-Sep due to further anticipated geomagnetic activity.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
02 Sep 109
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 30% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Enhanced by 35% after local dawn.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Enhanced 15% after local dawn.
Southern Australian Region:
Enhanced by 15% during local day.
Depressed 15-20% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day,
with spread F observed.
Monthly T index:
Month T index
Aug 115
Sep 84
Oct 81
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
03 Sep 60 Depressed 15 to 20%/near predicted monthly values
04 Sep 70 Depressed 10 to 15%/near predicted monthly values
05 Sep 95 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 85 was issued on
1 September and is current for 1-3 Sep. ASWFC HF Communications
Warning 86 was issued on 2 September and is current for 3 Sep
only. Maximum usable frequencies (MUFs) on UT day 02-Sep were
initially near predicted values to 15% enhanced, becoming depressed
by 15-20% after local dawn this morning for the southern Australian
region. Northern Australian region MUFs were 15% enhanced after
local dawn this morning. Strong spread F was observed at Hobart
during local night hours. MUFs at Hobart during local night hours
were depressed by 15-30%. A minor fadeout only impacting the
ionospheric E region was observed at Learmonth in association
with the M3 flare. For 03-Sep MUFs for the southern Australian
region are expected to be 15-20% depressed, whilst northern Australian
region MUFs are expected to remain near predicted monthly values
to 15% enhanced. Further depressed frequencies of ionospheric
support expected 04-Sep.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 01 Sep
Daily Proton Fluence >1 MeV: 2.4E+07
Daily Proton Fluence >10 MeV: 9.9E+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: B6.0
DSCOVR Satellite Solar Wind Day Averaged Data for 01 Sep
Speed: 408 km/sec Density: 6.0 p/cc Temp: 89600 K Bz: -3 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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