[Ips-dsgr] ASWFC Daily Report - 18 March 23 issued 2330 UT on 18 Mar 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Sun Mar 19 10:30:14 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 MARCH 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 MARCH AND FORECAST FOR 19 MARCH - 21 MARCH
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 18 Mar: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Mar: 140/94
1B. SOLAR FORECAST
19 Mar 20 Mar 21 Mar
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 138/92 138/92 138/92
COMMENT: Solar activity on UT day 18-Mar was at the R0 level.
Solar region AR3256(S22E63, beta) produced two C class flares,
the largest a C9.4 at 18/0716UT. This regions trailer spot has
now rotated into view, with another new region just visible to
the south and east of the trailer spot, numbered AR3257. Solar
region AR3234 appears not to have returned. In SDO171 imagery
at N22 on the north east limb there is some minor emission that
has yet to rotate onto the disk, but at this stage does not appear
that significant. The small spot groups in the south west solar
quadrant have decayed. There are currently only 3 numbered sunspot
regions on the visible disk. The other solar region AR3251(S15W49,alpha)
is small and uninteresting. No new Earth directed CMEs were observed.
Two behind the limb CMEs were observed off the north east limb
from 18/0124UT and 18/0744UT and another CME off the top of the
Sun from 18/0639UT from an erupting prominence. A south east
CME was observed from 18/1847UT associated with a limb prominence.
South west directed CME activity observed in LASCO C2 late on
17-Mar is considered as limb or behind the limb activity. Solar
activity is expected to be R0-R1, with an isolated low level
R1 flare possible from AR3256 and to a lesser extent from possible
activity on the north east solar limb. The solar wind speed on
UT day 18-Mar was steady and ranged from 409 to 472 km/s, and
is currently near 425 km/s. The peak total interplanetary field
strength (IMF, Bt) was 7 nT and the north-south IMF component
(Bz) range was +6 to -6 nT. The solar wind possibly remained
slightly elevated due to a small coronal hole now west of solar
central meridian. Solar wind parameters are expected to become
enhanced mid to late 19-Mar due to a recent filament eruption.
This CME is directed both south and west with modelling showing
a component will reach the Earth's magnetosphere but there is
a chance it will pass under the Earth. A large coronal hole is
visible in the far south east solar quadrant.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 18 Mar: G0
Estimated Indices 18 Mar : A K
Australian Region 7 22232121
Cocos Island 4 12122120
Darwin 7 23222122
Townsville 7 23222122
Learmonth 7 12232221
Alice Springs 7 23222122
Gingin 7 22232121
Canberra 6 22232111
Hobart 7 12233120
Estimated Antarctic Regional K Indices 18 Mar :
Macquarie Island 9 12153010
Casey 14 34433122
Mawson 20 44332253
Observed Regional daily pc3 Indices 18 Mar :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 4 (Quiet)
Canberra 0 (Quiet)
Hobart 6 (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 18 Mar : A
Fredericksburg 8
Planetary 9
Observed AFr/Ap Indices 17 Mar : A K
Fredericksburg 7
Planetary 6 1112 3112
2B. MAGNETIC FORECAST
Date Ap Conditions
19 Mar 30 Initially G0, increasing to G1 later in UT day,
with the chance of an isolated G2 period.
20 Mar 18 G1 periods early in UT day then G0.
21 Mar 8 G0
COMMENT: ASWFC Geomagnetic Warning 12 was issued on 18 March
and is current for 19-20 Mar. G0 geomagnetic conditions were
observed in the Australian region UT day 18-Mar. G0 conditions
generally observed in the Antarctic region, with an isolated
period of G1 observed at Mawson and Macquarie Island. ASWAS G1,
with the chance of a G2 period are expected from second half
of 19-Mar to early 20-Mar, due to a recent solar filament eruption/CME.
This CME has a southward component so there is a chance it may
pass under the Earth.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
18 Mar Normal Normal Fair-normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
19 Mar Normal Normal-poor Normal-poor
20 Mar Normal Poor-fair Poor
21 Mar Normal Fair-normal Fair-normal
COMMENT: HF propagation conditions on 18-Mar were normal. HF
propagation conditions on 19-Mar are initially expected to be
normal, then becoming degraded later in the UT day at middle
to high latitudes due to the anticipated arrival of a recent
CME associated with a solar filament eruption. Isolated minor
fadeouts possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
18 Mar 133
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 30% during local night.
Enhanced by 25% after local dawn.
Niue Island Region:
Enhanced by 35-70%.
Northern Australian Region:
Enhanced by 15-20%
Southern Australian Region:
Enhanced by 25-30%
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Feb 117
Mar 80
Apr 80
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
19 Mar 125 15 to 30% above predicted monthly values
20 Mar 80 Depressed 15%/15% above predicted monthly values
21 Mar 100 Near predicted monthly values
COMMENT: ASWFC Preliminary HF Communications Warning 30 was issued
on 18 March and is current for 20 Mar only. Maximum usable frequencies
(MUFs) on UT day 18-Mar in the Australian region were enhanced
by 15-70%. MUFs are expected to be enhanced by 15-30% on 19-Mar.
Southern Australian region MUFs are expected to become depressed
on 20-Mar if geomagnetic activity induced from a recent erupting
solar filament eventuates. Northern Australian region MUFs are
expected to remain enhanced. Isolated minor fadeouts possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 17 Mar
Daily Proton Fluence >1 MeV: 1.1E+06
Daily Proton Fluence >10 MeV: 4.7E+04
Daily Electron Fluence >2 MeV: 2.90E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B8.4
DSCOVR Satellite Solar Wind Day Averaged Data for 17 Mar
Speed: 435 km/sec Density: 4.4 p/cc Temp: 141000 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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