[Ips-dsgr] ASWFC Daily Report - 28 February 23 issued 2331 UT on 28 Feb 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Wed Mar 1 10:31:05 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/28 FEBRUARY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 28 FEBRUARY AND FORECAST FOR 01 MARCH - 03 MARCH
STATUS INDICATORS SOL:** YELLOW ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 28 Feb: R2
Flares Max Fadeout Freq. Sectors
M8.6 1750UT probable lower South American/
Atlantic
Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Feb: 161/115
1B. SOLAR FORECAST
01 Mar 02 Mar 03 Mar
Activity R0-R1, chance of R2R0-R1, chance of R2R0-R1, chance of R2
Fadeouts Possible Possible Possible
10.7cm/SSN 160/114 160/114 156/110
COMMENT: Solar activity on UT day 28-Feb was at the R2 level,
with an M8.6 flare at 28/1750UT produced by AR3234 (N24W33, beta).
There are currently 5 numbered sunspot regions on the solar disk
and 1 unnumbered region. AR3234 is the largest and most significant
sunspot region on the solar disk and produced an M-class flare
and several C-class flares on 28-Feb, this region showed decay
in its trailer spots over the 24 hour period. All other numbered
sunspot regions are either stable or in decay. An unnumbered
region is present at S15E70 with alpha magnetic characteristics.
An active sunspot region is visible over the northeast limb at
around N30, this could be returning region AR3213 which produced
15 M-class flares when last on the solar disk. This region is
expected to rotate onto the solar disk on 2-Mar. Solar activity
is expected to be at R0-R1 levels over 1-3 Mar, with a chance
of R2. A northwest directed CME was observed from 28/1758UT in
LASCO and STEREO-A imagery. An eruption is visible at around
N30W30 from 28/1744UT in H-Alpha and GOES SUVI imagery, associated
with the M8.6 flare from AR3234 at 28/1750UT. Modelling indicates
that this CME has a geoeffective component which is expected
to impact Earth on 4-Mar at 0600UT +/- 12 hours. This CME is
very slow and only a glancing impact is predicted, so any effects
are expected to be very mild. Several other CMEs were observed
over the UT day, but none are considered to be geoeffective.
The solar wind speed on UT day 28-Feb decreased for the majority
of the day, with an increase at around 28/1700UT followed by
another decrease. The wind speed ranged between 548 and 745 km/s,
and is currently near 630 km/s. The peak interplanetary field
strength (IMF, Bt) reached 10 nT and the north-south IMF component
(Bz) range was +9 to -7 nT. There was no shock associated with
the wind speed rise at 28/1700UT. The solar wind speed is expected
to decline over 1-2 Mar as coronal hole and CME induced high
speed wind stream effects wane. The solar wind speed is expected
to return to background levels by 3-Mar. The solar energetic
proton flux (>10 MeV) decreased to around background levels over
28-Feb. Further S1 conditions are unlikely.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 28 Feb: G0
Estimated Indices 28 Feb : A K
Australian Region 12 33332133
Cocos Island 7 32221122
Darwin - --------
Townsville 13 33332233
Learmonth 13 33332233
Alice Springs 12 33331133
Gingin 11 33322133
Canberra 11 33332132
Hobart 11 34331013
Estimated Antarctic Regional K Indices 28 Feb :
Macquarie Island 26 55443143
Casey 30 56542233
Mawson 53 64543276
Observed Regional daily pc3 Indices 28 Feb :
Darwin NA
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 23 (Quiet to unsettled)
Canberra 11 (Quiet)
Hobart 58 (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 Feb : A
Fredericksburg 18
Planetary 24
Observed AFr/Ap Indices 27 Feb : A K
Fredericksburg 60
Planetary 109 4578 7875
2B. MAGNETIC FORECAST
Date Ap Conditions
01 Mar 15 G0, chance G1
02 Mar 10 G0
03 Mar 8 G0
COMMENT: G2 and G1 geomagnetic conditions were observed at the
planetary level for one period each in the first part of the
UT day 28-Feb. G0 geomagnetic conditions were observed in the
Australian region on 28-Feb. G1 geomagnetic conditions were observed
at Macquarie Island, G1 conditions with a period of G2, were
observed at Casey and G2 conditions with a period of G3 were
observed at Mawson. G0 geomagnetic conditions, with a chance
of G1 are expected on 1-Mar as coronal hole and CME effects wane
and G0 conditions are expected on 2-3 Mar.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
28 Feb Fair Poor-fair Poor-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
01 Mar Normal Normal Normal-fair
02 Mar Normal Normal Normal-fair
03 Mar Normal Normal Normal-fair
COMMENT: HF propagation conditions were degraded on 28-Feb due
to geomagnetic activity. There is a chance of degraded conditions
on 1-Mar as geomagnetic activity subsides. Normal HF propagation
conditions are expected on 2-3 Mar. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
28 Feb 69
Observed Australian Regional MUFs
Cocos Island Region:
Mostly near predicted monthly values.
Enhanced by 45% after local dawn.
Niue Island Region:
Enhanced by 25% during local day.
Enhanced by 45% during local night.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Depressed by 35% during local day.
Depressed by 15% during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jan 119
Feb 75
Mar 76
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
01 Mar 75 Near predicted monthly values
02 Mar 90 Near predicted monthly values
03 Mar 90 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) in the Northern Australian
region on UT day 27-Feb were near monthly predicted values. MUFs
in the southern Australian region were depressed by up to 35%,
depressions of up to 35% were also observed at Learmonth during
local day. The depressed HF conditions are due to ongoing geomagnetic
activity due to a combination of coronal hole high speed wind
stream effects and two CME impacts on 26-Feb and 27-Feb. Significant
sporadic-E was observed at Hobart, Norfolk Island, Brisbane and
Townsville, mostly during local night. Spread F was observed
at Hobart and Perth during local night. MUFs are expected to
recover to near predicted monthly values, with some mild depressions
possible at high latitudes on 1-Mar as geomagnetic activity wanes.
MUFs are expected to be near monthly predicted values over 2-3
Mar. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 27 Feb
Daily Proton Fluence >1 MeV: 7.1E+07
Daily Proton Fluence >10 MeV: 2.3E+05
Daily Electron Fluence >2 MeV: 2.40E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.0
DSCOVR Satellite Solar Wind Day Averaged Data for 27 Feb
Speed: 687 km/sec Density: 4.8 p/cc Temp: 406000 K Bz: -5 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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