[Ips-dsgr] ASWFC Daily Report - 14 September 24 issued 2330 UT on 14 Sep 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Sun Sep 15 09:30:54 AEST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/14 SEPTEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 14 SEPTEMBER AND FORECAST FOR 15 SEPTEMBER - 17 SEPTEMBER
STATUS INDICATORS SOL:** RED ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 14 Sep: R3
Flares Max Fadeout Freq. Sectors
M1.0 0433UT possible lower E. Asia/Aust.
M3.0 0741UT possible lower Mid East/Indian
X4.5 1529UT probable all South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 14 Sep: 172/126
1B. SOLAR FORECAST
15 Sep 16 Sep 17 Sep
Activity R1-R2, chance R3 R1-R2, chance R3 R1-R2, chance R3
Fadeouts Probable Probable Probable
10.7cm/SSN 175/129 175/129 170/124
COMMENT: Solar activity on UT day 14-Sep was at the R3 level
due to an X4.5 flare at 14/1529UT, there was also an M1.0 flare
at 14/0433UT and an M3.0 flare at 14/0741UT. There are currently
six numbered sunspot regions visible on the solar disk. The most
significant sunspot group on the solar disk is AR3825 (S15E54,
gamma-delta). This is the largest sunspot group, is the most
magnetically complex and was responsible for all the notable
flares of the UT day. AR3825 showed development in trailer spots
on 14-Sep, as did AR3814 (N16W54, alpha) and AR3824 (S04W07,
beta), whilst AR3826 (S28W16, beta) recently developed onto the
solar disk. All other sunspot regions are either stable or in
decay. Solar activity is expected to be at R1-R2 levels over
15-17 Sep, with a chance of R3. The >10MeV proton flux measured
at GOES has increased following the X4.5 flare at 14/1529UT.
The flux is currently below the S1 threshold, however if this
increase continues at the current pace S1 conditions will occur
at the end of UT day 14-Sep or early on 15-Sep. S1 conditions
are expected on 15-Sep, with a chance of S1 on 16-17 Sep. Two
significant CMEs were observed over the UT day. A southwest directed
CME was observed in STEREO-A imagery from 14/0423UT associated
with an eruption on the western limb at around S30 from 14/0312UT
visible in SDO, GOES SUVI and H-Alpha imagery. Modelling suggests
this CME is not geoeffective and will pass in front of Earth.
A fast, east directed, partial halo CME was observed in SOHO
imagery from 14/1536UT. This CME is associated with the X4.5
flare at 14/1529UT and a visible eruption on the disk at around
S15W50 from 14/1524UT, visible in SDO, GOES SUVI and H-Alpha
imagery. Modelling suggests this CME will impact Earth on 16-Sep
at 1200UT +/- 12 hours. The solar wind speed on UT day 14-Sep
was steady, with a slight dip in the middle of the UT day. The
solar wind speed ranged from 380 to 485 km/s and is currently
near 470 km/s. The peak total interplanetary field strength (IMF,
Bt) was 10 nT and the north-south IMF component (Bz) range was
+7 to -8 nT. A slight jump in IMF conditions at 14/1015UT could
be due to the anticipated impact of a CME first observed on 11-Sep.
An anticipated CME impact on 14-Sep may have occurred at 14/1015UT
but there is a chance of a late impact on 15-Sep. A coronal hole
in the northern hemisphere is expected to be in a geoeffective
position by 15-Sep, further enhancing solar wind speed. A significant
increase in wind speed is expected on 16-Sep due to an anticipated
impact from a fast halo CME, first observed on 14-Sep, around
the middle of the UT day, this is expected to combine with a
possible glancing impact from a CME first observed on 13-Sep
and high speed wind stream effects from the coronal hole mentioned
above and another coronal hole in the southern hemisphere, expected
to be in a geoeffective position by 16-Sep. The solar wind speed
is expected to continue to be elevated on 17-Sep.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 14 Sep: G0
Estimated Indices 14 Sep : A K
Australian Region 11 22343122
Cocos Island 10 21433022
Darwin 11 23343022
Townsville 12 21443122
Learmonth 14 32253123
Alice Springs 9 22243022
Gingin 17 31453133
Canberra 10 22343021
Kennaook Cape Grim 11 23243122
Hobart 11 23243122
Estimated Antarctic Regional K Indices 14 Sep :
Macquarie Island 19 32355132
Casey 10 33332122
Mawson 36 52454165
Observed Regional daily pc3 Indices 14 Sep :
Darwin 12 (Quiet)
Townsville 10 (Quiet)
Learmonth 13 (Quiet)
Alice Springs 7 (Quiet)
Gingin 17 (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 14 Sep : A
Fredericksburg 20
Planetary 24
Observed AFr/Ap Indices 13 Sep : A K
Fredericksburg 22
Planetary 31 5544 4345
2B. MAGNETIC FORECAST
Date Ap Conditions
15 Sep 20 G0-G1
16 Sep 65 G3, chance G4
17 Sep 25 G0-G1
COMMENT: ASWFC Geomagnetic Warning 55 was issued on 14 September
and is current for 15-17 Sep. Mostly G0 geomagnetic conditions
were observed in the Australian region on UT day 14-Sep. Isolated
periods of G1 were observed at Learmonth and Gingin. Mostly G1
geomagnetic conditions were observed in the Antarctic region,
with a period of G2 observed at Mawson and G0 conditions observed
at Casey. G0-G1 conditions are expected on 15-Sep due to a possible
late impact from a CME first observed on 11-Sep combined with
high speed wind stream effects from a coronal hole in the northern
hemisphere. G3 geomagnetic conditions, with a chance of G4 are
expected on 16-Sep due to an anticipated impact from a halo CME
first observed on 14-Sep, combined with a possible glancing impact
from a CME first observed on 13-Sep and high speed wind stream
effects from the northern hemisphere coronal hole and a southern
hemisphere coronal hole. G0-G1 geomagnetic conditions are expected
on 17-Sep due to ongoing CME and coronal hole high speed wind
stream effects.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
14 Sep Normal-fair Normal-fair Poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
15 Sep Normal Normal-fair Fair
16 Sep Poor Poor Poor
17 Sep Normal Normal-fair Fair
COMMENT: HF radio communication conditions on UT day 14-Sep were
mostly normal to fair at low and mid latitudes and poor at high
latitudes. Mostly normal to fair HF conditions are expected on
15-Sep, with poor conditions expected at high latitudes due to
ongoing solar proton enhancements combined with potential geomagnetic
activity. Degraded conditions are likely on 16-Sep due to anticipated
geomagnetic activity and possible ongoing solar proton enhancements.
Conditions are expected to improve towards normal on 17-Sep.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
14 Sep 120
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 25% during local day.
Enhanced by 40% during local night.
Niue Island Region:
Enhanced by 25% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Mostly near predicted monthly values.
Southern Australian Region:
Depressed by 30% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 20% 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
15 Sep 130 Near predicted monthly values
16 Sep 100 Depressed 5 to 15%/near predicted monthly values
17 Sep 120 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 101 was issued on
13 September and is current for 13-15 Sep. Maximum usable frequencies
(MUFs) in the northern Australian region on UT day 14-Sep were
near predicted monthly values. MUFs in the southern Australian
region were near predicted monthly values to depressed by up
to 30%, with the strongest depressions observed during local
daylight hours. Spread F was observed at Hobart, Perth and Canberra.
MUFs are expected to be near predicted monthly values on 15-Sep,
with depressions possible in the southern Australian region.
Significant depressions, especially at high latitudes, are expected
on 16-Sep due to anticipated geomagnetic activity. MUFs are expected
to be in recovery towards predicted monthly values on 17-Sep.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 13 Sep
Daily Proton Fluence >1 MeV: 2.5E+06
Daily Proton Fluence >10 MeV: 4.5E+04
Daily Electron Fluence >2 MeV: 1.80E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 3%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C5.2
DSCOVR Satellite Solar Wind Day Averaged Data for 13 Sep
Speed: 483 km/sec Density: 0.8 p/cc Temp: 105000 K Bz: -5 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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