[Ips-dsgr] ASWFC Daily Report - 25 September 24 issued 2330 UT on 25 Sep 2024 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Thu Sep 26 09:30:49 AEST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 SEPTEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 SEPTEMBER AND FORECAST FOR 26 SEPTEMBER - 28 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Sep: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Sep: 174/128
1B. SOLAR FORECAST
26 Sep 27 Sep 28 Sep
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 172/126 168/122 166/120
COMMENT: Solar activity was R0 on UT day 25-Sep, however there
was a long duration C9 flare from AR3836 (S12E47, beta-gamma).
There are currently eight numbered sunspots on the disk. AR3833
(N22W64, beta) and AR3835 (S23E26, beta) have shown some growth
over the past day, but still remain generally small regions.
All other sunspots are either stable or in decay. Solar activity
is expected to be R0-R1 over 26-28 Sep.
No CMEs were observed on UT day 25-Sep, however imagery is currently
heavily limited. Some faint material may have been ejected in
association with the C9 flare, however is not expected to be
geoeffective.
S0 solar radiation storm conditions were observed on UT day 25-Sep.
S0 solar radiation storm conditions are expected over 26-28 Sep.
The solar wind environment is currently on a decline from slightly
elevated conditions, likely due to a small coronal hole. The
solar wind speed ranged from 414 to 575 km/s and is currently
near 500 km/s. The peak total interplanetary field strength (IMF,
Bt) was 12 nT and the north-south IMF component range (Bz) was
+8 to -11 nT with some intermittent periods of southward Bz.
While effects from the coronal hole are expected to diminish
over 26-27 Sep, the ACE EPAM data is indicating an increase in
low-energy protons, possibly suggesting a recent CME may arrive
shortly. In this case, the solar wind is expected to be disturbed
over 26-27 Sep, but returning to background conditions by 28-Sep.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Sep: G0
Estimated Indices 25 Sep : A K
Australian Region 19 43334433
Cocos Island 15 33323433
Darwin 14 33333332
Townsville 19 43344333
Learmonth 19 43333443
Alice Springs 17 42334333
Gingin 22 52333444
Canberra 19 43334433
Kennaook Cape Grim 23 43435433
Hobart 23 43435433
Estimated Antarctic Regional K Indices 25 Sep :
Macquarie Island 44 33555743
Casey 25 55442333
Mawson 55 64543467
Observed Regional daily pc3 Indices 25 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 4 (Quiet)
Canberra 6 (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 25 Sep : A
Fredericksburg 24
Planetary 33
Observed AFr/Ap Indices 24 Sep : A K
Fredericksburg 12
Planetary 18 3323 3335
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Sep 12 G0-G1
27 Sep 8 G0, chance G1
28 Sep 8 G0
COMMENT: Geomagnetic conditions in the Australian region on UT
day 25-Sep were G0, however there were several periods where
the Australian K-index was 4. G1-G3 geomagnetic conditions were
observed in the Antarctica region. G0-G1 geomagnetic conditions
are possible over 26-27 Sep due to a possible CME arrival. Conditions
are expected to return to mostly background levels by 28-Sep.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Sep Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Sep Normal Normal Normal
27 Sep Normal Normal Normal
28 Sep Normal Normal Normal
COMMENT: HF radio communication conditions were generally normal
on 25-Sep, with equatorial scintillation present around local
midnight hours. HF radio communication conditions are expected
to be generally normal over 26-28 Sep, however may become mildly
degraded with the arrival of a possible CME over the period.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Sep 136
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 20% during local night.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Mostly near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 15% 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
26 Sep 140 Near to 20% above predicted monthly values
27 Sep 140 Near predicted monthly values
28 Sep 130 Near predicted monthly values to 15% depressed
COMMENT: ASWFC SWF HF Communications Warning 106 was issued on
25 September and is current for 25-27 Sep. Maximum usable frequences
(MUFs) in the Australian region on UT day 25-Sep were near predicted
values to 15% enhanced. Spread F was observed in Hobart and Niue
during local night hours. Scintillation was observed in Niue
from 1045 to 1120 UT. MUFs are expected to be near predicted
monthly values over 26-28 Sep, initially enhanced by 20% but
possibly becoming depressed by 15% by the end of the period.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Sep
Daily Proton Fluence >1 MeV: 1.0E+06
Daily Proton Fluence >10 MeV: 1.5E+04
Daily Electron Fluence >2 MeV: 2.20E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.4
DSCOVR Satellite Solar Wind Day Averaged Data for 24 Sep
Speed: 429 km/sec Density: 8.3 p/cc Temp: 95500 K Bz: -1 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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