[Ips-dsgr] ASWFC Daily Report - 30 September 23 issued 2331 UT on 30 Sep 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Oct 1 10:31:23 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/30 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 30 SEPTEMBER AND FORECAST FOR 01 OCTOBER - 03 OCTOBER
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 30 Sep: R1
Flares Max Fadeout Freq. Sectors
M1.2 1635UT possible lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 30 Sep: 159/113
1B. SOLAR FORECAST
01 Oct 02 Oct 03 Oct
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 156/110 154/109 154/109
COMMENT: Solar activity on UT day 30-Sep was at the R1 level,
with an M1.2 flare at 30/1635UT produced by, newly numbered region,
AR3451 (N15E64, gamma). There are currently 6 numbered sunspot
regions visible on the solar disk and one unnumbered region.
AR3451 is the most significant sunspot region on the solar disk,
displaying significant spot development over 30-Sep and producing
the only M-class flare of the day. AR3449 (N15W04, beta-gamma)
and AR3450 (S18E30, beta-gamma) are also magnetically complex.
AR3450 showed spot development over the UT day and AR3449 displayed
trailer spot movement. AR3447 (S22W54, beta) also showed development.
All other sunspot regions are either stable or in decay. An unnumbered
region is visible at S24W41 with beta magnetic complexity, but
this region is currently very small. Solar activity is expected
to be at R0-R1 levels over 1-3 Oct. No geoeffective CMEs were
observed on 30-Sep. An eruption visible in SDO and GOES SUVI
imagery from 30/0336UT at around S20E30 is associated with a
slow southeast directed CME visible in SOHO and STEREO-A imagery
from 30/0430UT. Modelling indicates this CME is not geoeffective.
A broader, southwest directed, CME is visible in SOHO and SDO
imagery from 30/1905UT. This CME is associated with coronal movement
beyond the western limb, visible in GOES SUVI imagery from 30/1836UT.
Modelling indicates this CME is not geoeffective. The solar wind
speed on UT day 30-Sep was steady, ranging from 386 km/s to 474
km/s. The solar wind speed is currently around 420 km/s. The
total interplanetary field strength (IMF, Bt) was 6 nT and the
north-south IMF component (Bz) range was +3 to -5 nT. A sustained
period of mostly southward Bz began at 30/1455UT and is currently
ongoing. The solar wind speed is expected to remain steady, with
an increase possible over 2-3 Oct due to a coronal hole in the
northern hemisphere, which is expected to rotate into a geoeffective
position over the coming days.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 30 Sep: G0
Estimated Indices 30 Sep : A K
Australian Region 9 22223232
Cocos Island 8 22222232
Darwin 7 21222232
Townsville 8 21223232
Learmonth 9 22223232
Alice Springs 8 21123232
Gingin 8 21223232
Canberra 7 12223222
Hobart 9 12233232
Estimated Antarctic Regional K Indices 30 Sep :
Macquarie Island 16 22344341
Casey 15 44223233
Mawson 25 23323356
Observed Regional daily pc3 Indices 30 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 23 (Quiet to unsettled)
Canberra 32 (Quiet to unsettled)
Hobart 32 (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 30 Sep : A
Fredericksburg 8
Planetary 9
Observed AFr/Ap Indices 29 Sep : A K
Fredericksburg 13
Planetary 14 1222 2122
2B. MAGNETIC FORECAST
Date Ap Conditions
01 Oct 8 G0
02 Oct 14 G0, slight chance of G1
03 Oct 12 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 30-Sep. Mostly G0 geomagnetic conditions were
observed in the Antarctic region, with G2 conditions observed
at Mawson. G0 geomagnetic conditions are expected over 1-3 Oct,
with a slight chance of G1 on 2-Oct due to coronal hole high
speed wind stream effects from a coronal hole in the northern
hemisphere rotating towards a geoeffective position.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
30 Sep Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
01 Oct Normal Normal Normal-fair
02 Oct Normal Normal Normal-fair
03 Oct Normal Normal Normal-fair
COMMENT: HF radio propagation conditions were mostly normal on
30-Sep. Generally normal HF propagation conditions are expected
over 1-3 Oct, although some mild degradations may be observed
over 2-3 Oct at high latitudes due to coronal hole high speed
wind stream effects. Isolated minor shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
30 Sep 108
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Enhanced by 50% during local night.
Niue Island Region:
Enhanced by 40% during local day.
Near predicted monthly values during local night.
Northern Australian Region:
Near predicted monthly values.
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
01 Oct 125 Near to 15% above predicted monthly values
02 Oct 125 Near to 15% above predicted monthly values
03 Oct 120 Near to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Australian
region on UT day 30-Sep were near predicted monthly values in
the northern and southern Australian region. Spread-F was observed
at Hobart during local night hours. MUFs are expected to be near
predicted monthly values to 15% enhanced over 1-3 Oct. There
is a slight chance for minor depressions in the southern Australian
region on 2-3 Oct due to coronal hole high speed wind stream
effects. Isolated minor shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 29 Sep
Daily Proton Fluence >1 MeV: 5.0E+05
Daily Proton Fluence >10 MeV: 1.8E+04
Daily Electron Fluence >2 MeV: 8.90E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:10%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 29 Sep
Speed: 452 km/sec Density: 6.4 p/cc Temp: 122000 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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