[Ips-dsgr] ASWFC Daily Report - 28 April 23 issued 2331 UT on 28 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sat Apr 29 09:31:26 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/28 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 28 APRIL AND FORECAST FOR 29 APRIL - 01 MAY
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 28 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Apr: 150/105
1B. SOLAR FORECAST
29 Apr 30 Apr 01 May
Activity R1, chance of R2 R1, chance of R2 R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 145/99 145/99 145/99
COMMENT: Solar activity on UT day 28-Apr was at the R0 level,
with multiple flares at the C6 level. There are currently six
numbered sunspot regions visible on the solar disk. AR3288 (S23W15,
beta-gamma-delta) is the most magnetically complex region and
has exhibited spot development over the UT day, particularly
in its intermediate spots. AR3289 (N20E39, beta) also showed
development over 28-Apr. Both AR3288 and AR3289 were responsible
for the high C-class flares over the day, with AR3288 responsible
for the vast majority. All other sunspot regions are stable or
in decay. Solar activity is expected to be at the R1 level over
29-Apr to 1-May, with a chance of R2. No geoeffective CMEs were
observed over 28-Apr. An erupting prominence is visible from
the west limb at around S23 from 28/0953UT in H-Alpha, GOES SUVI
and SDO imagery. An associated west directed CME is visible from
28/1124UT in LASCO C2 and STEREO-A imagery. This CME is not geoeffective.
The solar wind speed on UT day 28-Apr increased, ranging from
516 to 740 km/s, and is currently near 685 km/s. The peak total
interplanetary field strength (IMF, Bt) was 5 nT and the north-south
IMF component (Bz) range was +5 to -5 nT. The solar wind is expected
to remain elevated over 29-Apr, with a decline expected over
30-Apr to 1-May as coronal hole high speed wind stream effects
wane. There is a slight change of an increase in the solar wind
speed over the second half of UT day 29-Apr, due to a possible
glancing impact from a CME first observed on 27-Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 28 Apr: G0
Estimated Indices 28 Apr : A K
Australian Region 16 23334432
Cocos Island 9 23223321
Darwin 10 23223322
Townsville 14 23333432
Learmonth 16 23334432
Alice Springs 16 23334432
Gingin 18 32334443
Canberra 12 23333322
Hobart 14 23234422
Estimated Antarctic Regional K Indices 28 Apr :
Macquarie Island 25 34445433
Casey 16 33343333
Mawson 57 44644675
Observed Regional daily pc3 Indices 28 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 2 (Quiet)
Alice Springs 0 (Quiet)
Gingin 28 (Quiet to unsettled)
Canberra 28 (Quiet to unsettled)
Hobart 32 (Quiet to unsettled)
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 28 Apr : A
Fredericksburg 18
Planetary 22
Observed AFr/Ap Indices 27 Apr : A K
Fredericksburg 20
Planetary 25 5533 4433
2B. MAGNETIC FORECAST
Date Ap Conditions
29 Apr 14 G0, chance of G1
30 Apr 10 G0
01 May 10 G0
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 28-Apr. Mostly G0 geomagnetic conditions were
observed at Macquarie Island and Casey, with an isolated period
of G1 at Macquarie Island. G1-G2 conditions were observed at
Mawson. G0 geomagnetic conditions, with a chance of G1 are expected
on 29-Apr due to ongoing coronal hole high speed wind stream
effects combined with a possible glancing impact in the second
half of the day from a CME first observed on 27-Apr. G0 geomagnetic
conditions are expected over 30-Apr to 1-May.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
28 Apr Normal Normal Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
29 Apr Normal Normal Normal-fair
30 Apr Normal Normal Normal-fair
01 May Normal Normal Normal-fair
COMMENT: Mostly normal HF propagations conditions were observed
on 28-Apr. Mostly normal HF propagation conditions are expected
over 29-Apr to 1-May. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
28 Apr 107
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 45% during local day.
Enhanced by 25% during local night.
Enhanced by 25% after local dawn.
Niue Island Region:
Enhanced by 15% during local day.
Enhanced by 20% during local night.
Northern Australian Region:
Enhanced by 20% during local day.
Near predicted monthly values during local night.
Southern Australian Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Depressed 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
29 Apr 110 Near to 15% above predicted monthly values
30 Apr 110 Near to 15% above predicted monthly values
01 May 110 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 28-Apr in the Australian region were near predicted
monthly values to 20% enhanced during local day. Strong spread
F was observed at Hobart during local night hours. Significant
spread E was observed at Brisbane and Mawson, with some spread
E observed at Cocos Islands, Hobart and Perth all during local
night hours. MUFs are expected to be near predicted monthly values
to 15% enhanced over 29-Apr to 1-May. Shortwave fadeouts are
possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 27 Apr
Daily Proton Fluence >1 MeV: 3.14E+5
Daily Proton Fluence >10 MeV: 2.21E+4
Daily Electron Fluence >2 MeV: 9.28E+7
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 27 Apr
Speed: 604 km/sec Density: 1.2 p/cc Temp: 224000 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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