[Ips-dsgr] ASWFC Daily Report - 22 April 23 issued 2330 UT on 22 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Apr 23 09:30:10 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/22 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 22 APRIL AND FORECAST FOR 23 APRIL - 25 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 22 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 22 Apr: 141/95
1B. SOLAR FORECAST
23 Apr 24 Apr 25 Apr
Activity R0, chance R1 R0, chance R1 R0, chance R1
Fadeouts Possible Possible Possible
10.7cm/SSN 140/94 135/89 135/89
COMMENT: Solar activity on UT day 22-Apr was at the R0 level,
with several low level C-class flares. There are currently six
numbered sunspot regions visible on the solar disk and one unnumbered
region. AR3282 (N11W47, beta) remains the largest region on the
disk and has shown some minor development in its intermediate
spots. AR3279 (S19W65, alpha) has exhibited spot growth over
the UT day. An unnumbered region recently appeared at N15E40
(alpha) and is stable and unremarkable. The background level
of X-ray flux has declined to B-class levels. Solar activity
is expected to be at the R0 level over 23-25 Apr, with a chance
of R1. Several CMEs were observed, but none are considered geoeffective.
An eastward CME was observed, visible in LASCO C2 coronagraph
imagery from 22/0424UT. This CME is considered to originate from
a farside source and is therefore not geoeffective. The solar
wind speed on UT day 22-Apr increased in the first half of the
UT day before decreasing late in the day, ranging from 370 to
450 km/s, and is currently near 380 km/s. The peak total interplanetary
field strength (IMF, Bt) was 6 nT and the north-south IMF component
(Bz) range was +5 to -5 nT. A large coronal hole in the southern
solar hemisphere may increase solar wind speeds over 23-24 Apr,
but its influence is likely limited due to its southern extent.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 22 Apr: G0
Estimated Indices 22 Apr : A K
Australian Region 3 22100112
Cocos Island 3 22000012
Darwin 3 22100012
Townsville 4 22100122
Learmonth 5 23100122
Alice Springs 2 12100011
Gingin 4 22000222
Canberra 3 12100112
Hobart 2 12100111
Estimated Antarctic Regional K Indices 22 Apr :
Macquarie Island 1 12000001
Casey 9 34311112
Mawson 20 43210146
Observed Regional daily pc3 Indices 22 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 0 (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 22 Apr : A
Fredericksburg 7
Planetary 8
Observed AFr/Ap Indices 21 Apr : A K
Fredericksburg 8
Planetary 9 2112 2323
2B. MAGNETIC FORECAST
Date Ap Conditions
23 Apr 60 G2-G3
24 Apr 30 G1, chance G2
25 Apr 12 G0
COMMENT: ASWFC Geomagnetic Warning 19 was issued on 21 April
and is current for 23-24 Apr. G0 geomagnetic conditions were
observed in the Australian region on UT day 22-Apr. Mostly G0
geomagnetic conditions were observed in the Antarctic region,
with an isolated period of G2 observed at Mawson. G2-G3 geomagnetic
conditions are expected on 23-Apr due to the expected arrival
of a CME first observed on 21-Apr. G1 geomagnetic conditions
are expected on 24-Apr, with a chance of G2 as CME impacts abate.
G0 geomagnetic conditions are expected on 25-Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
22 Apr Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
23 Apr Poor Poor Poor
24 Apr Fair Fair Fair-poor
25 Apr Normal Normal Normal-fair
COMMENT: Mostly normal HF propagation conditions were observed
on 22-Apr, with some degradations observed during local night
hours. Fair to poor HF conditions are expected over 23-24 Apr
due to a CME impact from a CME first observed on 21-Apr. Mostly
normal HF propagation conditions are expected on 25-Apr.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
22 Apr 116
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 25% during local day.
Enhanced by 95% during local night.
Niue Island Region:
Near predicted monthly values 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:
Enhanced by 20% during local day.
Near predicted monthly values 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
23 Apr 105 Near predicted monthly values
24 Apr 60 Depressed 15%/near predicted monthly values
25 Apr 95 Near predicted monthly values
COMMENT: ASWFC Preliminary HF Communications Warning 38 was issued
on 22 April and is current for 23-24 Apr. Maximum usable frequencies
(MUFs) on UT day 22-Apr in the Australian region were enhanced
by 15-20%. Sporadic-E was observed at Brisbane, Learmonth and
Perth. Spread F was observed at Hobart and Perth during local
night hours. MUFs are expected to be near predicted monthly values
on 23 and 25-Apr. MUFs are expected to be depressed by 15% on
24-Apr due to a CME impact on 23-Apr.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 21 Apr
Daily Proton Fluence >1 MeV: 4.3E+04
Daily Proton Fluence >10 MeV: 2.3E+04
Daily Electron Fluence >2 MeV: 1.40E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B6.5
DSCOVR Satellite Solar Wind Day Averaged Data for 21 Apr
Speed: 379 km/sec Density: 4.1 p/cc Temp: 48400 K Bz: -2 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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