[Ips-dsgr] ASWFC Daily Report - 27 September 23 issued 2330 UT on 27 Sep 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Thu Sep 28 09:30:07 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 SEPTEMBER AND FORECAST FOR 28 SEPTEMBER - 30 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Sep: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Sep: 156/110
1B. SOLAR FORECAST
28 Sep 29 Sep 30 Sep
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 160/114 158/112 155/109
COMMENT: Solar activity on UT day 27-Sep was R0, with no significant
solar flares. There are currently six numbered sunspots on the
solar disk, and also a new region rotating on near S20. A number
of these spots are magnetically complex, but most of them have
shown either stability or decay in the past 24 hours. AR3449
(N15E38, gamma) has shown some minor growth over the past day.
Solar activity is expected to be R0-R1 over 28-30 Sep, with a
slight chance for R2. A CME was observed to the north-northwest
from 27/1124 UT but is not expected to be geoeffective. No other
CMEs were observed in the available coronagraph imagery. The
solar wind speed on UT day 27-Sep was variable and ranged between
526 to 417 km/s. The solar wind speed began the UT day relatively
strong but on a declining trend, then increased from 17/1640
UT. The peak total interplanetary field strength (IMF, Bt) was
7 nT and the north-south IMF component (Bz) range was +6 to -5
nT. The solar wind is expected to return to background levels
on 38-Sep, but may possibly increase briefly on 29-Sep due to
a possible expected weak glancing blow from a CME. The solar
wind speed is then expected to be at background levels on 30-Sep.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 Sep: G0
Estimated Indices 27 Sep : A K
Australian Region 14 33343321
Cocos Island 11 23333320
Darwin 14 33343322
Townsville 14 33343321
Learmonth 17 33344421
Alice Springs 14 33343321
Gingin 12 33333321
Canberra 12 33342221
Hobart 10 33332211
Estimated Antarctic Regional K Indices 27 Sep :
Macquarie Island 10 33333110
Casey 21 45533221
Mawson 33 55454344
Observed Regional daily pc3 Indices 27 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 9 (Quiet)
Canberra 13 (Quiet)
Hobart 34 (Quiet to unsettled)
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 27 Sep : A
Fredericksburg 14
Planetary 16
Observed AFr/Ap Indices 26 Sep : A K
Fredericksburg 26
Planetary 32 3445 6434
2B. MAGNETIC FORECAST
Date Ap Conditions
28 Sep 9 G0
29 Sep 12 G0, slight chance for G1
30 Sep 8 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 27-Sep. G0-G1 geomagnetic conditions were observed
in the Antarctica region. Mostly G0 geomagnetic conditions are
expected over 28-30 Sep, but there is a slight chance for G1
on 29-Sep due to a possible weak glancing blow from a recent
CME.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 Sep Normal-fair Fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 Sep Normal Normal-fair Fair
29 Sep Normal Normal-fair Fair
30 Sep Normal Normal-fair Normal-fair
COMMENT: HF radio propagation conditions on UT day 27-Sep were
mostly normal, although some degradations were observed at middle
and high latitudes at local dawn hours. Generally normal HF propagation
conditions are expected over 28-30 Sep, with mild degradations
possible on 29-Sep during local dawn hours. Isolated shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 Sep 113
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 25% during local day.
Enhanced by 25% during local night.
Niue Island Region:
Enhanced by 25% during local day.
Enhanced by 25% 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):
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
28 Sep 115 10 to 15% above predicted monthly values
29 Sep 115 10 to 15% above predicted monthly values
30 Sep 115 10 to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 27-Sep were near predicted values to 15% enhanced.
Spread-F was observed at Hobart, Canberra and Perth during local
dawn hours. Sporadic-E was observed at Brisbane and Learmonth
during local dawn hours. Spread-F may continue at high-to-mid
latitudes over the next day, but generally HF conditions are
expected to recover over 28-30 Sep. Isolated minor shortwave
fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 Sep
Daily Proton Fluence >1 MeV: 4.0E+06
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 1.10E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 26 Sep
Speed: 474 km/sec Density: 7.4 p/cc Temp: 215000 K Bz: -3 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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