[Ips-dsgr] ASWFC Daily Report - 11 August 23 issued 2334 UT on 11 Aug 2023 [SEC=OFFICIAL]
rwc
rwc at ips.gov.au
Sat Aug 12 09:34:24 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/11 AUGUST 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 11 AUGUST AND FORECAST FOR 12 AUGUST - 14 AUGUST
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 11 Aug: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Aug: 153/108
1B. SOLAR FORECAST
12 Aug 13 Aug 14 Aug
Activity R0-R1, chance R2 R0-R1, chance R2 R0-R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 150/105 145/99 140/94
COMMENT: Solar activity on UT day 11-Aug was at the R0 level,
with several high C-class flares. There are currently seven numbered
sunspot regions visible on the solar disk. AR3394 (S20W44, beta)
and AR3395 (N15W30, gamma-delta) are the largest and most significant.
AR3394 exhibited spot decay and has reduced in magnetic complexity,
whilst AR3395 showed significant development. Neither active
region has produced an M-class flare during their time on the
solar disk. All other sunspot regions are either stable or in
decay. Solar activity is expected to be at R0-R1 levels, with
a chance of R2 over 12-14 Aug. The >10 MeV proton flux was enhanced
over 11-Aug but was below the S1 threshold. The flux is expected
to remain enhanced over 12-13 Aug with the chance of an S1 event
if significant flare activity occurs near the west limb. No geoeffective
CMEs were observed on 11-Aug. A slow southeast directed CME was
observed in LASCO C2 imagery from 11/0125UT. This CME is considered
far side and not geoeffective. An east directed CME is visible
in LASCO C2 and STEREO-A imagery from 11/0653UT, associated with
an eruption on the east limb visible in GOES SUVI and SDO imagery
from 11/0525UT at around N20. This CME is not considered geoeffective.
A slow southwest directed CME is visible in LASCO C2 and STEREO-A
imagery from 11/1038UT, associated with an eruption beyond the
western limb visible in GOES SUVI imagery from 11/0903UT. Modelling
indicates this CME has no geoeffective component and will pass
ahead of the Earth. The solar wind speed on 11-Aug was moderate
and steady, ranging from 380 to 500 km/s and is currently near
435 km/s. The peak total interplanetary field strength (IMF,
Bt) was 8 nT and the north-south IMF component (Bz) range was
+7 to -5 nT. The solar wind speed is expected to remain moderate
over 12-13 Aug, with a gradual decline towards background levels.
An increase is expected on 14-Aug due to high speed wind stream
effects from a northern hemisphere coronal hole, rotating towards
a geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 11 Aug: G0
Estimated Indices 11 Aug : A K
Australian Region 2 11100111
Cocos Island 2 -1210100
Darwin 4 22210112
Townsville 3 11210112
Learmonth 3 21200111
Alice Springs 2 12100102
Gingin 2 20100110
Canberra 1 11000101
Hobart 1 11100101
Estimated Antarctic Regional K Indices 11 Aug :
Macquarie Island 0 00000000
Casey 8 43310111
Mawson 9 32321123
Observed Regional daily pc3 Indices 11 Aug :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (Quiet)
Hobart 0 (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 11 Aug : A
Fredericksburg 6
Planetary 5
Observed AFr/Ap Indices 10 Aug : A K
Fredericksburg 8
Planetary 8 2222 2322
2B. MAGNETIC FORECAST
Date Ap Conditions
12 Aug 5 G0
13 Aug 8 G0
14 Aug 12 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
and Antarctic regions on UT day 11-Aug. G0 geomagnetic conditions
are expected over 12-13 Aug. G0 conditions, with a chance of
G1 are expected on 14-Aug due to high speed wind stream effects
from a coronal hole rotating towards a geoeffective position.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
11 Aug Normal-fair Normal-fair Fair-normal
PCA Event : 10MeV Proton/PCA Event Began at 0105UT 08/08, Ended at 0915UT 10/08
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
12 Aug Normal Normal Normal
13 Aug Normal Normal Normal-fair
14 Aug Normal Normal Normal-fair
COMMENT: HF propagation conditions on UT day 11-Aug were generally
normal to fair, with more degraded conditions at high latitudes
during the first half of the day due to enhanced solar proton
conditions. HF propagation conditions are expected to be mostly
normal over 12-14 Aug. Isolated shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
11 Aug 112
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 50% during local day.
Enhanced by 90% during local night.
Niue Island Region:
Mostly near predicted monthly values.
Enhanced by 20% after local dawn.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Enhanced by 15% during local day.
Enhanced by 15% during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jul 103
Aug 88
Sep 84
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
12 Aug 110 Near to 15% above predicted monthly values
13 Aug 110 Near to 15% above predicted monthly values
14 Aug 110 Near to 15% above predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 79 was issued on
11 August and is current for 11-13 Aug. Maximum usable frequencies
(MUFs) on UT day 11-Aug were near predicted monthly values to
15% enhanced in the southern Australian region and near predicted
monthly values in the northern Australian region. Spread-F was
observed in Hobart and Canberra during local night hours. MUFs
are expected to be near predicted monthly values to 15% enhanced
over 12-14 Aug. Isolated shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 10 Aug
Daily Proton Fluence >1 MeV: 1.3E+07
Daily Proton Fluence >10 MeV: 7.4E+05
Daily Electron Fluence >2 MeV: 3.50E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B9.6
DSCOVR Satellite Solar Wind Day Averaged Data for 10 Aug
Speed: 379 km/sec Density: 3.4 p/cc Temp: 48200 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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