[Ips-dsgr] ASWFC Daily Report - 27 February 23 issued 2331 UT on 27 Feb 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Tue Feb 28 10:31:07 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 FEBRUARY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 FEBRUARY AND FORECAST FOR 28 FEBRUARY - 02 MARCH
STATUS INDICATORS SOL:** YELLOW ** MAG:** RED ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Feb: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Feb: 161/115
1B. SOLAR FORECAST
28 Feb 01 Mar 02 Mar
Activity R0-R1 R0-R1 R0-R1
Fadeouts Possible Possible Possible
10.7cm/SSN 160/114 158/112 154/109
COMMENT: Solar activity on UT day 27-Feb was at the R0 level,
with multiple C-class flares. The largest was a C4.5 flare at
27/1022UT, produced by AR3234 (N24W21, beta-delta). There are
currently 7 numbered sunspot regions on the solar disk and 1
unnumbered region. AR3234 showed sunspot development over the
UT day and is the largest and most magnetically complex region
on the solar disk, although it has not produced an M-class flare
since 23-Feb. AR3229 (N26W73, alpha), which produced the major
flaring on 24-25 Feb, showed decay over the UT day and is soon
to rotate off the solar disk. All other numbered sunspot regions
are stable or in decay. An unnumbered region is present at S04W10
with beta magnetic characteristics, this region developed over
the UT day. Solar activity is expected to be at R0-R1 levels
over 28-Feb to 2-Mar, with a chance of R2. Several CMEs were
observed over the UT day, but none are considered to be geoeffective.
The solar wind speed on UT day 27-Feb increased, ranging between
523 and 883 km/s, and is currently near 700 km/s. A moderate
shock was observed in the solar wind at 27/1018UT, likely due
to an anticipated impact from a CME first observed on 25-Feb.
The peak interplanetary field strength (IMF, Bt) reached 20 nT
and the north-south IMF component (Bz) range was +13 to -19 nT.
Bz was predominately southward over 27-Feb, with the longest
period of sustained Bz at -5 nT or lower occurring from 27/0518UT
to 27/1141UT. The solar wind speed is expected to decline over
28-Feb to 2-Mar as coronal hole and CME induced high speed wind
stream effects wane. The shock in the solar wind on 27-Feb is
likely due to an impact from the CME forecast to arrive on 28-Feb,
however there is a slight chance that further CME-caused enhancements
may occur on 28-Feb. In the absence of further CME activity,
the solar wind speed is expected to return to background levels
on 2-Mar. The solar energetic proton flux (>10 MeV) remains enhanced,
but below the S1 threshold. Further S1 conditions are unlikely.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 27 Feb: G2
Estimated Indices 27 Feb : A K
Australian Region 46 44565555
Cocos Island 33 33354555
Darwin 41 44465455
Townsville 46 44565555
Learmonth 60 55566556
Alice Springs 49 54565555
Gingin 54 54466556
Canberra 44 44565554
Hobart 75 44677664
Estimated Antarctic Regional K Indices 27 Feb :
Macquarie Island 95 45776775
Casey 44 56545445
Mawson 83 65666676
Observed Regional daily pc3 Indices 27 Feb :
Darwin 2 (Quiet)
Townsville 4 (Quiet)
Learmonth 35 (Quiet to unsettled)
Alice Springs 16 (Quiet)
Gingin 95 (Minor storm)
Canberra 105 (Major storm)
Hobart NA
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 27 Feb : A
Fredericksburg 60
Planetary 102
Observed AFr/Ap Indices 26 Feb : A K
Fredericksburg 18
Planetary 22 3234 2155
2B. MAGNETIC FORECAST
Date Ap Conditions
28 Feb 32 G1-G2, chance of G3
01 Mar 18 G0-G1
02 Mar 12 G0, chance of G1
COMMENT: ASWFC Geomagnetic Warning 8 was issued on 26 February
and is current for 26-28 Feb. G3 geomagnetic conditions were
observed at the planetary level on UT day 27-Feb. Mostly G1 geomagnetic
conditions were observed in the Australian region on 27-Feb,
with one period of G2. Two periods of G3 conditions were observed
at Hobart. G3 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.
A very weak (6 nT) shock was observed at 27/1017UT, likely indicating
the arrival of a CME first observed on 25-Feb however there is
a slight chance that this CME is yet to arrive. G1-G2 geomagnetic
conditions, with a chance of an isolated period of G3, are expected
on 28-Feb due to ongoing geomagnetic activity. G0-G1 geomagnetic
conditions are expected on 1-Mar and G0 conditions with a chance
of G1 are expected on 2-Mar as coronal hole and CME effects wane.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
27 Feb Normal-fair Fair Fair-poor
PCA Event : 10MeV Proton/PCA Event Began at 2100UT 25/02, Ended at 1830UT 26/02
and, 10MeV Proton/PCA Event Began at 1935UT 26/02, Ended at 2005UT 26/02
and, 10MeV Proton/PCA Event Began at 2035UT 26/02, Ended at 2245UT 26/02
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
28 Feb Fair Fair Fair-poor
01 Mar Normal Normal-fair Fair
02 Mar Normal Normal Normal-fair
COMMENT: Degraded HF conditions are expected on 28-Feb particularly
at high latitudes, due to ongoing geomagnetic activity. HF conditions
are expected to recover over 1-2 Mar, with a chance of degraded
conditions on 1-Mar, particularly at high latitudes. Shortwave
fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
27 Feb 90
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Near predicted monthly values during local night.
Enhanced by 20% after local dawn.
Niue Island Region:
Enhanced by 35% during local day.
Enhanced by 50% during local night.
Enhanced by 45% after local dawn.
Northern Australian Region:
Depressed by 15% during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Mostly near predicted monthly values.
Depressed by 35% after local dawn.
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
28 Feb 80 Near predicted monthly values
01 Mar 95 Near to 15% above predicted monthly values
02 Mar 95 Near to 15% above predicted monthly values
COMMENT: ASWFC HF Communications Warning 23 was issued on 26
February and is current for 27-28 Feb. Maximum usable frequencies
(MUFs) in the Northern Australian region on UT day 27-Feb were
between 15% depressed and 15% enhanced. MUFs in the southern
Australian region were near monthly predicted values to 35% depressed,
with the strongest depressions occurring at Hobart during local
night. 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 27-Feb and 28-Feb. Significant
sporadic-E was observed at Norfolk Island and Niue during local
night and Brisbane during local dawn. Spread F was observed at
Hobart during local night. MUFs are expected to be near predicted
monthly values to 20% depressed over 28-Feb, due to ongoing geomagnetic
activity. The strongest depressions are expected at higher latitudes.
MUFs are expected to recover to near predicted monthly values
to 15% enhanced over 1-2 Mar as geomagnetic activity wanes, with
mild depressions possible on 1-Mar in the southern Australian
region. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 26 Feb
Daily Proton Fluence >1 MeV: 1.7E+08
Daily Proton Fluence >10 MeV: 2.8E+06
Daily Electron Fluence >2 MeV: 2.20E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.6
DSCOVR Satellite Solar Wind Day Averaged Data for 26 Feb
Speed: 474 km/sec Density: 18.3 p/cc Temp: 181000 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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