[Ips-dsgr] ASWFC Daily Report - 03 September 23 issued 2330 UT on 03 Sep 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Mon Sep 4 09:30:44 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/03 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 03 SEPTEMBER AND FORECAST FOR 04 SEPTEMBER - 06 SEPTEMBER
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 03 Sep: R2
Flares Max Fadeout Freq. Sectors
M1.1 0023UT possible lower West Pacific
M6.0 0836UT probable lower Mid East/Indian
Observed 10.7 cm flux/Equivalent Sunspot Number for 03 Sep: 131/85
1B. SOLAR FORECAST
04 Sep 05 Sep 06 Sep
Activity R0 R0 R0
Fadeouts None expected None expected None expected
10.7cm/SSN 130/84 135/89 130/84
COMMENT: Solar activity on UT day 03-Sep was R2. Solar region
AR3413 produced M1 and M6 flares from behind the north west solar
limb and is due back to the north east limb on 16-Sep. There
are currently 5 numbered solar regions on the the disk, with
newly emerging AR3420(S21E37, beta), and two new small unnumbered
regions at N15E19 and N13E40. Stable solar region AR3415(S07W88,
beta) is rotating off disk. All solar regions are currently small,
with region AR3417(S05W02, beta-gamma) the most complex. No new
significantly Earth directed CMEs were observed on 03-Sep. In
LASCO C2 westward CME events were observed at 03/0036UT, 03/0536UT,
03/0912UT and 03/1325UT which are considered associated with
behind the limb activity from AR3413 and are not Earth directed.
A small solar filament was active in GONG Big Bear imagery centred
at N15W08 at 03/1937UT. The solar wind speed on UT day 03-Sep
declined, ranging from 430 to 550km/sec. No shocks were observed
in the solar wind on 03-Sep. The peak total interplanetary field
strength (IMF, Bt) was 9 nT and the north-south IMF component
(Bz) range was +5 to -7 nT. The IMF Bz component was orientated
mildly southward during the period 03/0718-1823UT. The ACE EPAM
CME precursor data channel now shows a peak at 02/1600UT with
the flux currently declining and has not reassumed an increasing
trend. This suggests that a weak indistinct CME transit may have
passed the Earth combined with elevated coronal hole solar wind
conditions. However, the IMF total field (Bt) profile over recent
days has not shown a significant increase which is typical of
CME transients. At this stage it is considered more likely that
the CME that was expected over 02-03 Sep from the filament eruption
late on 30-Aug has transited the Earth's orbital distance. A
small coronal hole is visible just to the east of solar central
meridian at N40.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 03 Sep: G0
Estimated Indices 03 Sep : A K
Australian Region 13 33442212
Cocos Island 11 33422311
Darwin 12 33432212
Townsville 15 33443222
Learmonth 19 43543312
Alice Springs 14 33532212
Gingin 14 42432322
Canberra 13 33442212
Hobart 18 33552212
Estimated Antarctic Regional K Indices 03 Sep :
Macquarie Island 35 43574312
Casey 18 44532213
Mawson 45 64533437
Observed Regional daily pc3 Indices 03 Sep :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 44 (Unsettled)
Canberra 41 (Unsettled)
Hobart 72 (Active)
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 03 Sep : A
Fredericksburg 20
Planetary 28
Observed AFr/Ap Indices 02 Sep : A K
Fredericksburg 25
Planetary 38 3455 5445
2B. MAGNETIC FORECAST
Date Ap Conditions
04 Sep 15 G0, chance of G1
05 Sep 15 G0, chance of G1
06 Sep 10 G0, slight chance of G1
COMMENT: ASWFC Geomagnetic Warning 48 was issued on 1 September
and is current for 2-4 Sep. G0 geomagnetic conditions were observed
in the Australian region on UT day 03-Sep. A period of planetary
G2 was observed 03/00-03UT. In the Antarctic region G1-G3 periods
were observed at Macquarie Island, a G1 period was observed at
Casey and isolated periods of G1-G2 at Mawson. The anticipated
CME induced activity expected on 03-Sep did not eventuate. There
is a chance for weak glancing blows from recent predominately
westward directed CMEs over the next few days.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
03 Sep Normal Fair Fair-poor
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
04 Sep Normal Normal-fair Fair
05 Sep Normal Normal Normal-fair
06 Sep Normal Normal Normal-fair
COMMENT: HF radio propagation conditions on UT day 03-Sep were
degraded at middle to high latitudes. Generally improving HF
conditions are expected with degraded conditions possible during
local night hours for middle to high latitudes.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
03 Sep 76
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Depressed by 20% during local night.
Niue Island Region:
Enhanced by 20-30%.
Northern Australian Region:
Near predicted monthly values to 15% enhanced.
Southern Australian Region:
Depressed by 20-25% local day.
Near predicted monthly values to 15-20% depressed,
local night.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 35% over the UT day.
Monthly T index:
Month T index
Aug 115
Sep 84
Oct 81
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
04 Sep 90 Near predicted monthly values
05 Sep 90 Near predicted monthly values
06 Sep 90 Near predicted monthly values
COMMENT: ASWFC Preliminary HF Communications Warning 84 was issued
on 31 August and is current for 3-4 Sep. Maximum usable frequencies
(MUFs) on UT day 03-Sep were depressed by 15-25% for the southern
Australian region. Northern Australian region MUFs were generally
near predicted monthly values to 15% enhanced. Strong spread
F was observed at Hobart during local night hours. A very minor
brief fadeout only impacting the ionospheric E region was observed
at Darwin in association with the M1 flare. For 04-06 Sep MUFs
now expected to be near predicted monthly values, with degraded
HF conditions likely during local night hours 04-05 Sep for the
southern Australian region.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 02 Sep
Daily Proton Fluence >1 MeV: 2.0E+07
Daily Proton Fluence >10 MeV: 1.6E+05
Daily Electron Fluence >2 MeV: 5.00E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B6.3
DSCOVR Satellite Solar Wind Day Averaged Data for 02 Sep
Speed: 538 km/sec Density: 1.5 p/cc Temp: 62700 K Bz: -4 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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