[Ips-dsgr] ASWFC Daily Report - 17 April 23 issued 2330 UT on 17 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Tue Apr 18 09:30:10 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 APRIL AND FORECAST FOR 18 APRIL - 20 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Apr: 167/121
1B. SOLAR FORECAST
18 Apr 19 Apr 20 Apr
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 170/124 168/122 168/122
COMMENT: Solar activity on UT day 17-Apr was at the R0 level,
with several C-class flares. There are currently eight numbered
sunspot regions visible on the solar disk and one unnumbered
region. AR3282 (N11E14, beta) is the largest sunspot region and
has shown growth in its leader spot over the UT day. AR3283 (S19E42,
beta) has exhibited minor growth in its main spot. AR3280 (S08W77,
beta) will soon rotate over the western limb. An unnumbered region
recently rotated over the eastern limb at S08E81 (alpha) and
appears to be growing. All other sunspot regions are either stable
or in decay. The background level of X-ray flux remains at C-class
levels. Solar activity is expected to be at R0-R1 levels over
18-20 Apr. Several CMEs were observed, but none are considered
geoeffective. A filament eruption was observed, visible in H-alpha
imagery at ~N20W02 from 17/0408UT. However, no associated CME
has been observed in the available coronagraph imagery. The solar
wind speed on UT day 17-Apr increased, ranging from 325 to 480
km/s, and is currently near 480 km/s. The peak total interplanetary
field strength (IMF, Bt) was 10 nT and the north-south IMF component
(Bz) range was +8 to -8 nT. The solar wind speed is expected
to remain elevated over 18-20 Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 17 Apr: G0
Estimated Indices 17 Apr : A K
Australian Region 4 12211201
Cocos Island 2 12210100
Darwin 4 21211201
Townsville 5 22212201
Learmonth 4 22212200
Alice Springs 3 11211201
Gingin 3 12211200
Canberra 3 11211201
Hobart 3 11211201
Estimated Antarctic Regional K Indices 17 Apr :
Macquarie Island 1 00011200
Casey 11 34421201
Mawson 8 22212204
Observed Regional daily pc3 Indices 17 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 2 (Quiet)
Hobart 0 (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 17 Apr : A
Fredericksburg 5
Planetary 5
Observed AFr/Ap Indices 16 Apr : A K
Fredericksburg 4
Planetary 5 1122 1122
2B. MAGNETIC FORECAST
Date Ap Conditions
18 Apr 8 G0
19 Apr 16 G0, chance G1
20 Apr 12 G0
COMMENT: ASWFC Geomagnetic Warning 18 was issued on 17 April
and is current for 19-21 Apr. G0 geomagnetic conditions were
observed in the Australian and Antarctic regions on 17-Apr. G0
geomagnetic conditions are expected over 18-20 Apr, with a chance
of G1 on 19-Apr due to weak glancing blow(s) from recent CME
activity.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
17 Apr Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
18 Apr Normal Normal Normal-fair
19 Apr Normal Normal-fair Fair
20 Apr Normal Normal Normal-fair
COMMENT: Normal HF propagation conditions were observed on 17-Apr.
Mostly normal HF propagation conditions are expected over 18-20
Apr. Mild degradations are possible for middle to high latitudes
on 19-Apr. Isolated shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
17 Apr 119
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 25% during local day.
Enhanced by 100% during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 20-30% during local night and after local dawn.
Northern Australian Region:
Mostly near predicted monthly values.
Southern Australian Region:
Enhanced by 15% during local day.
Enhanced by 20-25% during local night and after local dawn.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Enhanced by 20% over the UT day.
Monthly T index:
Month T index
Mar 132
Apr 84
May 84
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
18 Apr 115 15-20% above predicted monthly values
19 Apr 115 15-20% above predicted monthly values
20 Apr 115 15-20% above predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 37 was issued on
16 April and is current for 17-19 Apr. Maximum usable frequencies
(MUFs) on UT day 17-Apr in the Australian region were enhanced
by 15-25%. Strong enhancements were observed at Cocos Island.
Spread F was observed during local night hours at Hobart. MUFs
are expected to be 15-20% enhanced over 18-20 Apr. Isolated shortwave
fadeouts are possible. Mildly degraded conditions are possible
during local night hours on 19-Apr for southern Australian regions
due to possible arrival of a weak CME component.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 16 Apr
Daily Proton Fluence >1 MeV: 3.3E+04
Daily Proton Fluence >10 MeV: 2.3E+04
Daily Electron Fluence >2 MeV: 1.30E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 16 Apr
Speed: 335 km/sec Density: 2.0 p/cc Temp: 42700 K Bz: 0 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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