[Ips-dsgr] ASWFC Daily Report - 15 September 23 issued 2330 UT on 15 Sep 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sat Sep 16 09:30:42 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/15 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 15 SEPTEMBER AND FORECAST FOR 16 SEPTEMBER - 18 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 15 Sep: R1
Flares Max Fadeout Freq. Sectors
M1.7 2229UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 15 Sep: 139/93
1B. SOLAR FORECAST
16 Sep 17 Sep 18 Sep
Activity R1,chance R2 R1,chance R2 R1,chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 140/94 140/94 135/89
COMMENT: Solar activity on UT day 15-Sep was at the R1 level,
due to an M1.7 flare from AR3429(N11W06, beta-delta). This region has
showed development, with two main spots growing in area and other
surrounding spots relatively small. The eastern most of the two larger
spots within this region has developed a magnetic delta spot,
with a steep magnetic gradient evident, increasing the chance
of flare activity. Other regions are minor and either stable
or in decay. There are currently six numbered sunspot regions
visible on the solar disk. Solar activity is expected to be at
R1 level, with the chance of an R2 flare from AR3429, over 16-18
Sep. A previously flaring solar region AR3413 is due to return
around 16-Sep near solar latitude N10. There is some emission
visible at N10 in SDO171 imagery, and also some limb activity
in SDO304 imagery at 15/1848UT. No significantly Earth-directed
CMEs were observed on 15-Sep, with a faint eastward directed
CME in progress from 15/0000UT and a north directed CME observed
in LASCO C2 from 15/0449UT. A large solar filament near the centre
of the solar disk just to the north of AR3429 appears very unstable
in GONG H-alpha imagery, and may possibly erupt. The solar wind
speed was variable on 15-Sep, ranging from 426 to 498 km/s and
is currently near 449 km/s. The peak total interplanetary field
strength (IMF, Bt) was 9 nT and the north-south IMF component
(Bz) range was +7 to -5 nT. An enhancement in solar wind speed
is expected during the interval from late 16-Sep to mid 17-Sep
due to the anticipated arrival of a CME observed on 14-Sep. However,
at this stage the ACE EPAM CME precursor channel is only showing
a slight upward trend, possibly indicating a weak or later than
initially expected CME arrival.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 15 Sep: G0
Estimated Indices 15 Sep : A K
Australian Region 5 22101312
Cocos Island 3 22110201
Darwin 6 22101303
Townsville 8 32101323
Learmonth - --------
Alice Springs 5 21101303
Gingin 6 21101313
Canberra 5 12102312
Hobart 5 11102312
Estimated Antarctic Regional K Indices 15 Sep :
Macquarie Island 5 12002312
Casey 12 44322212
Mawson 19 33212336
Observed Regional daily pc3 Indices 15 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 4 (Quiet)
Canberra 2 (Quiet)
Hobart 12 (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 15 Sep : A
Fredericksburg 7
Planetary 9
Observed AFr/Ap Indices 14 Sep : A K
Fredericksburg 13
Planetary 24 4332 3554
2B. MAGNETIC FORECAST
Date Ap Conditions
16 Sep 18 G0, G1 periods possible late in UT day
17 Sep 25 G1, chance G2
18 Sep 16 G0, G1 periods early in UT day
COMMENT: ASWFC Geomagnetic Warning 51 was issued on 15 September
and is current for 15-17 Sep. G0 geomagnetic conditions were
observed in the Australian and Antarctic region on 15-Sep. G0-G1
geomagnetic conditions, with a chance of G2, are expected from
late 16-Sep to 17-Sep due to the anticipated arrival of a CME
first observed on 14-Sep.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
15 Sep Normal Normal Fair-normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
16 Sep Normal Normal-fair Normal-fair
17 Sep Normal Normal-fair Fair
18 Sep Normal Fair-normal Fair-normal
COMMENT: HF radio propagation conditions on UT day 15-Sep were
normal. Moderately degraded HF conditions are expected for middle
to high latitudes on 17-Sep due to anticipated geomagnetic activity
from a recent CME. Isolated shortwave fadeouts are expected.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
15 Sep 97
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values.
Niue Island Region:
Near predicted monthly values during local day.
Enhanced by 25-30%.
Northern Australian Region:
Enhanced by 20% during local day.
Near predicted monthly values during local night.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Aug 115
Sep 96
Oct 93
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
16 Sep 100 Near predicted monthly values
17 Sep 90 Near predicted monthly values/depressed 10 to
15%
18 Sep 90 Depressed 10 to 15%/near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 91 was issued on
14 September and is current for 14-16 Sep. ASWFC Preliminary
HF Communications Warning 92 was issued on 15 September and is
current for 17-18 Sep. Maximum usable frequencies (MUFs) on UT
day 15-Sep were generally near predicted monthly values. Spread
F was observed during local night hours at Hobart and Canberra.
A minor fadeout was observed at Niue in association with the
M1 flare at 15/2229UT. MUFs are expected to be near predicted
monthly values on 16-Sep, with depressions of up to 15% expected
on 17-18 Sep due to anticipated geomagnetic activity, with the
mild depressions expected to be more prevalent in the southern
Australian region. Isolated shortwave fadeouts are expected.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 14 Sep
Daily Proton Fluence >1 MeV: 1.0E+06
Daily Proton Fluence >10 MeV: 2.4E+04
Daily Electron Fluence >2 MeV: 6.20E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 14 Sep
Speed: 481 km/sec Density: 10.4 p/cc Temp: 148000 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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