[Ips-dsgr] ASWFC Daily Report - 09 April 23 issued 2330 UT on 09 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Mon Apr 10 09:31:00 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/09 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 09 APRIL AND FORECAST FOR 10 APRIL - 12 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 09 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 09 Apr: 140/94
1B. SOLAR FORECAST
10 Apr 11 Apr 12 Apr
Activity R1, chance R2 R1, chance R2 R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 140/94 145/99 150/105
COMMENT: Solar activity on UT day 09-Apr was at the R0 level,
with several C-class flares. The largest flare was a C9.0 at
09/0608UT produced by AR3272 (S21E30, beta-gamma). There are
currently two numbered sunspot regions visible on the solar disk
and three unnumbered regions. AR3272 is the largest sunspot region
and has shown some minor decay in its intermediate spots. Newly
numbered AR3273 (N10E27, beta-gamma) has shown rapid development
since appearing on the disk. Three unnumbered regions are visible
at S07E19 (beta), S23W02 (alpha) and N19E75 (alpha), all of which
are so far unremarkable. The background level of X-ray flux has
increased to C-class levels over the UT day. Solar activity is
expected to be at the R1 level over 10-12 Apr, with a chance
of R2. Several CMEs were observed over the UT day. A west directed
CME was observed, visible in LASCO C2 coronagraph imagery from
09/0948UT. This CME is likely associated with on-disk activity
near N15W62 visible in SDO imagery. Modelling indicates this
CME does not contain an Earth-directed component. A filament
was observed lifting off the solar disk in H-alpha imagery at
S20W50 from 09/0137UT. A subsequent CME was observed in STEREO-A
imagery from 09/0609UT. Modelling suggests this CME is not geoeffective.
An additional filament eruption was observed in H-alpha imagery
at 09/1900UT near S35W35. Initial modelling of the subsequent
CME suggests a slight chance of an Earth-directed component,
however further analysis is to be completed when additional imagery
becomes available. No other Earth-directed CMEs have been observed.
The solar wind speed on UT day 09-Apr declined, ranging from
295 to 350 km/s, and is currently near 335 km/s. The peak total
interplanetary field strength (IMF, Bt) was 7 nT and the north-south
IMF component (Bz) range was +4 to -4 nT. The solar wind speed
is expected to increase late on 10-Apr due to a small equatorial
coronal hole now rotating towards a geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 09 Apr: G0
Estimated Indices 09 Apr : A K
Australian Region 2 21100021
Cocos Island 3 22100121
Darwin 2 21100012
Townsville 2 211010--
Learmonth 2 21100021
Alice Springs 3 20100022
Gingin 3 22100022
Canberra 1 10000011
Hobart 3 11101121
Estimated Antarctic Regional K Indices 09 Apr :
Macquarie Island 1 10011100
Casey 8 23321122
Mawson 15 53222224
Observed Regional daily pc3 Indices 09 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 09 Apr : A
Fredericksburg 6
Planetary 6
Observed AFr/Ap Indices 08 Apr : A K
Fredericksburg 5
Planetary 4 1211 1101
2B. MAGNETIC FORECAST
Date Ap Conditions
10 Apr 6 G0
11 Apr 18 G0-G1
12 Apr 12 G0
COMMENT: ASWFC Geomagnetic Warning 17 was issued on 8 April and
is current for 11-12 Apr. G0 geomagnetic conditions were observed
in the Australian region on 09-Apr. Mostly G0 geomagnetic conditions
were observed in the Antarctic region, with an isolated period
of G1 observed at Mawson. G0 geomagnetic conditions are expected
on 10-Apr. G0-G1 geomagnetic conditions are expected on 11-Apr
due to the combined effects of a CME impact from a CME first
observed on 07-Apr and coronal hole high speed wind stream effects
from a small equatorial coronal hole. G0 geomagnetic conditions
are expected on 12-Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
09 Apr Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
10 Apr Normal Normal Normal
11 Apr Normal Normal-fair Fair
12 Apr Normal Normal Normal-fair
COMMENT: Normal HF propagation conditions were observed on 09-Apr.
Normal HF conditions are expected over 10-12 Apr. Mild degradations
at middle to high latitudes are possible on 11-Apr due to an
expected increase in geomagnetic activity. Isolated shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
09 Apr 122
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 45% during local day.
Enhanced by 65% during local night.
Niue Island Region:
Mostly near predicted monthly values.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 15-30% during local night and after local dawn.
Southern Australian Region:
Enhanced by 25% during local day.
Enhanced by 15-20% during local night and after local dawn.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values 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
10 Apr 130 Near to 15% above predicted monthly values
11 Apr 130 Near to 15% above predicted monthly values
12 Apr 130 Near to 15% above predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 09-Apr in
the Australian region were enhanced by 15-30%. MUFs are expected
to be near predicted monthly values to 15% enhanced over 10-12
Apr. Mild degradations are possible on 11-Apr due to expected
increase in geomagnetic activity. Isolated shortwave fadeouts
are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 08 Apr
Daily Proton Fluence >1 MeV: 2.6E+04
Daily Proton Fluence >10 MeV: 2.2E+04
Daily Electron Fluence >2 MeV: 7.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 9%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B7.7
DSCOVR Satellite Solar Wind Day Averaged Data for 08 Apr
Speed: 367 km/sec Density: 1.1 p/cc Temp: 33000 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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