[Ips-dsgr] ASWFC Daily Report - 31 July 23 issued 2330 UT on 31 Jul 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Tue Aug 1 09:30:09 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 JULY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 JULY AND FORECAST FOR 01 AUGUST - 03 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 31 Jul: R1
Flares Max Fadeout Freq. Sectors
M1.7 0900UT possible lower Mid East/Indian
Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Jul: 177/131
1B. SOLAR FORECAST
01 Aug 02 Aug 03 Aug
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 175/129 175/129 170/124
COMMENT: Solar activity on UT day 31-Jul was at the R1 level,
with an M1.7 flare at 31/0951UT from AR3390 (S18E37, beta). There
are currently eleven numbered sunspot regions on the solar disk
and one unnumbered region. AR3380 (S11W37, beta-gamma-delta)
and AR3386 (N11W05, beta-gamma) are the largest and most magnetically
complex regions on the solar disk and showed development over
the UT day. However, neither region has produced any significant
flare activity aside from an M1.4 flare on 29-Jul from AR3380.
AR3384 (S16W21, beta), AR3389 (S08E29, alpha), AR3392 (N10E48,
beta) and AR3393 (N17E28, alpha) have also shown growth in the
past 24 hours. AR3390, which produced the only M-class flare
of the day, appears stable. An unnumbered region has recently
rotated on to the solar disk at around N18E72 with alpha magnetic
complexity. All other regions were stable over the UT day. Solar
activity is expected to be at the R1 level, with a chance of
R2 over 1-3 Aug. The 10 MeV proton flux declined over 31-Jul
and is currently enhanced but at the S0 level and declining.
No further enhancements are expected, and conditions are likely
to remain at S0. No geoeffective CMEs were observed over 31-Jul.
A filament eruption is visible in GOES SUVI and H-Alpha imagery
from 31/0656UT at around N20E45. A slow filament liftoff is visible
in SDO, GOES SUVI and H-Alpha imagery from 31/1500UT at around
S12E01, although the start time is difficult to discern. No CMEs
are visible in currently available coronagraph imagery. There
is a possibility a CME associated with the slow filament lift
off has occurred, further analysis will be performed when more
imagery becomes available. The solar wind speed declined on 31-Jul,
ranging between 504 to 343 km/s and is currently near 380 km/s.
The peak total interplanetary field strength (IMF, Bt) was 6
nT and the north-south IMF component (Bz) range was +3 to -5
nT. An increase in solar wind speed is expected on 1-Aug due
to an anticipated impact from a CME first observed on 28-July.
The solar wind speed is expected to remain elevated on 2-Aug,
with a decline expected on 3-Aug as CME effects wane.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 31 Jul: G0
Estimated Indices 31 Jul : A K
Australian Region 3 11112201
Cocos Island 3 12111101
Darwin 4 21111202
Townsville 5 12212212
Learmonth 4 21221201
Alice Springs 3 11111201
Gingin 4 11122202
Canberra 3 11112201
Hobart 4 11122201
Estimated Antarctic Regional K Indices 31 Jul :
Macquarie Island 6 11223300
Casey 5 22211202
Mawson 13 23422314
Observed Regional daily pc3 Indices 31 Jul :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 4 (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 31 Jul : A
Fredericksburg 8
Planetary 8
Observed AFr/Ap Indices 30 Jul : A K
Fredericksburg 18
Planetary 9 2322 2222
2B. MAGNETIC FORECAST
Date Ap Conditions
01 Aug 30 G1-G2
02 Aug 12 G0
03 Aug 5 G0
COMMENT: ASWFC Geomagnetic Warning 42 was issued on 30 July and
is current for 1-2 Aug. G0 geomagnetic conditions were observed
in the Australian and Antarctic regions on UT day 31-Jul. G1-G2
geomagnetic conditions are expected on 1-Aug due to an impact
from a CME first observed on 28-Jul. G0 conditions are expected
on 2-3 Aug.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
31 Jul Normal Normal Normal-fair
PCA Event : 10MeV Proton/PCA Event Began at 0035UT 29/07, Ended at 1615UT 30/07
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
01 Aug Fair Fair Fair-poor
02 Aug Normal Normal Normal-fair
03 Aug Normal Normal Normal
COMMENT: HF propagation conditions on UT day 31-Jul were mostly
normal. Mildly degraded conditions are possible over 1-2 Aug,
particularly at high latitudes due to anticipated geomagnetic
activity, from a CME first observed on 28-Jul. Isolated shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
31 Jul 112
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.
Enhanced by 25% after local dawn.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Enhanced by 15% during local day.
Enhanced by 20% during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jun 98
Jul 91
Aug 88
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
01 Aug 100 Near predicted monthly values/depressed 10 to
15%
02 Aug 90 Near predicted monthly values/depressed 10 to
15%
03 Aug 115 Near to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 31-Jul were
near predicted monthly values with enhancements of up to 20%
observed in the southern Australian region. Sporadic-E was observed
at Cocos Islands, Niue and Darwin during local night hours. Spread
F was observed at Hobart. Scintillation was observed at Niue
between 31/0808UT and 31/0908UT. MUFs are expected to be near
predicted monthly values to 15% depressed over 1-2 Aug, particularly
in the southern Australian region, due to anticipated geomagnetic
activity from a CME first observed on 28-Jul. MUFs are expected
to be near predicted monthly values to 15% enhanced on 3-Aug.
Isolated shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 30 Jul
Daily Proton Fluence >1 MeV: 3.0E+07
Daily Proton Fluence >10 MeV: 1.7E+06
Daily Electron Fluence >2 MeV: 1.50E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.3
DSCOVR Satellite Solar Wind Day Averaged Data for 30 Jul
Speed: 485 km/sec Density: 5.3 p/cc Temp: 216000 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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