[Ips-dsgr] ASWFC Daily Report - 29 April 23 issued 2330 UT on 29 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Apr 30 09:30:58 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/29 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 29 APRIL AND FORECAST FOR 30 APRIL - 02 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 29 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 29 Apr: 156/110
1B. SOLAR FORECAST
30 Apr 01 May 02 May
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 155/109 150/105 150/105
COMMENT: Solar activity on UT day 29-Apr was at the R0 level,
with several high level C-class flares. There are currently five
numbered sunspot regions visible on the solar disk and one unnumbered
region. AR3288 (S21W30, beta-gamma-delta) is the most magnetically
complex region and has exhibited trailer spot development over
the UT day. AR3289 (N20E26, gamma-delta) also showed development
over 29-Apr. Both AR3288 and AR3289 were responsible for the
high level C-class flares over the day, with AR3288 responsible
for the vast majority. AR3291 (N08W26, beta) displayed trailer
spot development over the UT day. All other sunspot regions are
stable. An unnumbered sunspot region is visible at N18W36 with
beta magnetic characteristics. Solar activity is expected to
be at the R1 level over 30-Apr to 2-May, with a chance of R2.
A filament eruption is visible in GOES SUVI, SDO and H-Alpha
imagery from 29/0249UT at around N35E60. An associated northeast
directed CME is visible in LASCO and STEREO-A imagery from 29/0353UT.
Modelling suggests this CME has a chance of a glancing impact
with Earth at 02/1800UT +/- 12 hours. An eruption is visible
in GOES SUVI, SDO and H-Alpha imagery from 29/0137UT between
S20-S30 and E10-W35. An associated south directed CME is visible
in LASCO and STEREO-A imagery from 29/0353UT. Modelling suggests
this CME has a chance of a glancing impact with Earth at 02/2200UT
+/- 12 hours. Both of these CMEs are slow and were produced by
small solar filaments. Any geomagnetic activity due to glancing
impacts from these CMEs is unlikely to exceed the G1 level. Other
eruptions were also visible on the solar disk from 29/1221UT
at around S27E22 and 29/1617UT at around N05W20. No associated
CME is visible for either of these in currently available coronagraph
imagery. Further analysis will be performed when more imagery
is available. The solar wind speed on UT day 29-Apr was elevated,
ranging from 554 to 720 km/s, and is currently near 580 km/s.
The peak total interplanetary field strength (IMF, Bt) was 6
nT and the north-south IMF component (Bz) range was +5 to -6
nT. A period of sustained Bz from -5 to -6 nT occurred from 29/0900UT
to 29/1052UT. The solar wind speed is expected to remain elevated
over 30-Apr, with a decline possible from 1-May onwards as coronal
hole high speed wind stream effects wane. However, there is a
chance that a coronal hole in the northern hemisphere will cause
the solar wind speed to remain elevated over 1-2 May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 29 Apr: G0
Estimated Indices 29 Apr : A K
Australian Region 13 22343332
Cocos Island 11 22234321
Darwin 8 22233221
Townsville 13 22343332
Learmonth 18 22344442
Alice Springs 12 22343322
Gingin 18 22344442
Canberra 13 22343332
Hobart 17 22453332
Estimated Antarctic Regional K Indices 29 Apr :
Macquarie Island 38 33665443
Casey 21 44444332
Mawson 63 55555675
Observed Regional daily pc3 Indices 29 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 32 (Quiet to unsettled)
Canberra 65 (Active)
Hobart 63 (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 29 Apr : A
Fredericksburg 15
Planetary 20
Observed AFr/Ap Indices 28 Apr : A K
Fredericksburg 16
Planetary 22 4523 3433
2B. MAGNETIC FORECAST
Date Ap Conditions
30 Apr 12 G0, chance of G1
01 May 12 G0, chance of G1
02 May 18 G0-G1
COMMENT: Mostly G0 geomagnetic conditions were observed in the
Australian region on UT day 29-Apr, with an isolated period of
G1 at Hobart. G0 geomagnetic conditions were observed at Casey,
mostly G1 conditions with periods of G2 and G3 were observed
at Mawson and G2 conditions were observed at Macquarie Island.
G0 geomagnetic conditions, with a chance of G1, are expected
over 30-Apr to 1-May due to ongoing coronal hole high speed wind
stream effects. G0-G1 conditions are expected on 2-May due to
ongoing coronal hole high speed wind stream effects combined
with the chance of two glancing impacts from CMEs, first observed
on 29-Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
29 Apr Fair Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
30 Apr Normal Normal Normal-fair
01 May Normal Normal Normal-fair
02 May Normal Normal-fair Fair
COMMENT: Mostly normal HF propagations conditions were observed
on 29-Apr. Mostly normal HF propagation conditions are expected
over 30-Apr to 2-May. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
29 Apr 100
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 45% during local day.
Near predicted monthly values during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 15% during local day.
Depressed by 15% during local night.
Enhanced by 20% after local dawn.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Depressed by 35% 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
30 Apr 100 Near to 15% above predicted monthly values
01 May 100 Near to 15% above predicted monthly values
02 May 100 Near to 15% above predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 40 was issued on
28 April and is current for 28-30 Apr. Maximum usable frequencies
(MUFs) on UT day 29-Apr in the Australian region were near predicted
monthly values, with mild enhancements during local day. Spread
F was observed at Hobart and Canberra during local night hours.
Sporadic E was observed at Brisbane, Cocos Islands, Hobart, Learmonth
and Townsville during local night hours. MUFs are expected to
be near predicted monthly values to 15% enhanced over 30-Apr
to 2-May. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 28 Apr
Daily Proton Fluence >1 MeV: 1.9E+05
Daily Proton Fluence >10 MeV: 2.2E+04
Daily Electron Fluence >2 MeV: 1.40E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:13%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B6.9
DSCOVR Satellite Solar Wind Day Averaged Data for 28 Apr
Speed: 656 km/sec Density: 1.2 p/cc Temp: 249000 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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