[Ips-dsgr] ASWFC Daily Report - 19 April 23 issued 2331 UT on 19 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Thu Apr 20 09:31:05 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 APRIL AND FORECAST FOR 20 APRIL - 22 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Apr: 147/101
1B. SOLAR FORECAST
20 Apr 21 Apr 22 Apr
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 145/99 140/94 135/89
COMMENT: Solar activity on UT day 19-Apr was at the R0 level,
with several low level C class flares. There are currently five
numbered sunspot regions on the solar disk. AR3281 (S21W07, beta)
has shown some growth. All other sunspot regions are either stable
or in decay. No geoeffective CMEs were observed. Solar activity
is expected to be at R0-R1 levels over 20-22 Apr. The solar wind
speed on UT day 19-Apr was on a general declining trend and ranged
between 601 to 435 km/s. The peak total interplanetary magnetic
field strength (IMF, Bt) was 10 nT and the north-south IMF component
(Bz) range was +6 to -8 nT. Bz was southward between 19/0825-1425UT.
The solar wind speed is expected to increase over 20-22 Apr due
to anticipated impacts from recent CMEs, and a small coronal
hole wind stream expected to become geoeffective by the end of
the period.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 19 Apr: G0
Estimated Indices 19 Apr : A K
Australian Region 9 22233311
Cocos Island 6 21232210
Darwin 8 12233311
Townsville 9 22233311
Learmonth 8 22233310
Alice Springs 8 12233311
Gingin 8 22233310
Canberra 7 11133301
Hobart 9 12133401
Estimated Antarctic Regional K Indices 19 Apr :
Macquarie Island 16 01155400
Casey 12 24333221
Mawson 18 53223343
Observed Regional daily pc3 Indices 19 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 2 (Quiet)
Hobart 3 (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 19 Apr : A
Fredericksburg 16
Planetary 21
Observed AFr/Ap Indices 18 Apr : A K
Fredericksburg 9
Planetary 13 1110 3543
2B. MAGNETIC FORECAST
Date Ap Conditions
20 Apr 20 G0, chance G1
21 Apr 16 G0, chance G1
22 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 region on UT day 19-Apr. Mostly G0
geomagnetic conditions were observed in the Antarctic region,
with isolated periods of G1 observed at Macquarie Island and
Mawson. Mostly G0 geomagnetic conditions are expected over 20-22
Apr, with possible isolated periods of G1 due to weak glancing
blow(s) from recent CME activity over 20-21 Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
19 Apr Normal-fair Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
20 Apr Normal Normal-fair Normal-fair
21 Apr Normal Normal-fair Normal-fair
22 Apr Normal Normal-fair Normal-fair
COMMENT: Mostly normal HF propagation conditions were observed
on 19-Apr, with some mild degradations during local night hours.
Mostly normal HF propagation conditions are expected over 20-22
Apr, with further mild degradations possible over 20-21 Apr.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
19 Apr 127
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 25% during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 25% during local day.
Enhanced by 15% during local night.
Enhanced by 20% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 50% during local night.
Enhanced by 20% after local dawn.
Southern Australian Region:
Enhanced by 25% during local day.
Enhanced by 20% during local night.
Enhanced by 20% after local dawn.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Enhanced by 15% 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
20 Apr 120 15-20% above predicted monthly values
21 Apr 120 15-20% above predicted monthly values
22 Apr 110 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 19-Apr in
the Australian region were enhanced by 15-50%, with the largest
enhancements observed in the northern regions. Sporadic-E was
observed in Brisbane and Townsville and spread-F was observed
at Hobart during local night hours. Scintillation was observed
at Weipa from 19/1150-1420UT. MUFs are expected to be 15-20%
enhanced over 20-22 Apr. Mildly degraded conditions are possible
during local night hours over 20-21 Apr due to possible geomagnetic
activity.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 18 Apr
Daily Proton Fluence >1 MeV: 3.4E+05
Daily Proton Fluence >10 MeV: 2.2E+04
Daily Electron Fluence >2 MeV: 1.50E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 18 Apr
Speed: 478 km/sec Density: 5.1 p/cc Temp: 236000 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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