[Ips-dsgr] ASWFC Daily Report - 25 February 25 issued 2330 UT on 25 Feb 2025 [SEC=OFFICIAL]
Australian Space Weather Forecasting Centre
aswfc at bom.gov.au
Wed Feb 26 10:30:51 AEDT 2025
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 FEBRUARY 2025
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 FEBRUARY AND FORECAST FOR 26 FEBRUARY - 28 FEBRUARY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Feb: R1
Flares Max Fadeout Freq. Sectors
M3.9 24/2302UT possible lower West Pacific
M1.3 0247UT possible lower E. Asia/Aust.
M3.6 1159UT possible lower European
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Feb: 190/143
1B. SOLAR FORECAST
26 Feb 27 Feb 28 Feb
Activity R1, chance R2 R1, chance R2 R1, chance R2
Fadeouts Possible Possible Possible
10.7cm/SSN 190/143 190/143 185/138
COMMENT: Solar activity on UT day 25-Feb was at the R1 level
due to two M-class flares, the largest of which was an M3.6 flare
at 25/1159UT produced by AR3998 (S12W51, beta). There are currently
seven numbered sunspot regions visible on the solar disk. AR3998
is the largest region on the disk and has decayed over the UT
day. AR4000 (N18W44, beta) has also decayed. AR3996 (S15W65,
beta) has shown mild growth in its trailer spot. AR4006 (N17E34,
beta) has exhibited mild growth in its intermediate spots. AR4007
(S12E34, beta) has shown spot growth. Newly numbered region AR4008
(N07E68, alpha) recently rotated over the eastern limb and is
stable. All other sunspot regions are either stable or in decay.
Solar activity is expected to be at the R1 level over 26-28 Feb,
with a chance of R2. S1 solar radiation storm conditions were
observed on UT day 25-Feb, which declined to S0 in the second
half of the UT day. S0 solar proton conditions are expected over
26-28 Feb, with a chance of S1. A filament eruption was observed,
visible in H-alpha imagery from 25/1133UT immediately prior to
the M3.6 flare from AR3998. A subsequent southwest-directed CME
was observed, visible in STEREO-A coronagraph imagery from 25/1238UT.
Preliminary modelling suggests this CME does not have an Earth-directed
component, however further modelling will be completed when additional
coronagraph imagery becomes available. No other Earth-directed
CMEs have been observed. The solar wind speed on UT day 25-Feb
decreased, ranging from 330 to 430 km/s and is currently near
330 km/s. The peak total interplanetary field strength (IMF,
Bt) was 16 nT and the north-south IMF component (Bz) range was
+13 to -11 nT. A sustained period of southward IMF conditions
was observed over the interval 25/1840-2153UT. Two coronal holes
are currently crossing the central meridian and are expected
to influence the solar wind speed on 28-Feb. The solar wind speed
is expected to remain near background levels over 26-27 Feb,
then increase on 28-Feb due to coronal hole high speed wind stream
effects.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Feb: G0
Estimated Indices 25 Feb : A K
Australian Region 7 22221123
Cocos Island 6 22211132
Darwin 6 22221122
Townsville 8 22221133
Learmonth 9 32222133
Alice Springs 7 22221123
Gingin 7 22211133
Canberra 6 12221023
Kennaook Cape Grim 6 12221123
Hobart 6 12212123
Estimated Antarctic Regional K Indices 25 Feb :
Macquarie Island 7 11113223
Casey 20 44532233
Mawson 16 33522224
Observed Regional daily pc3 Indices 25 Feb :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 18 (Quiet)
Canberra 11 (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 25 Feb : A
Fredericksburg 7
Planetary 7
Observed AFr/Ap Indices 24 Feb : A K
Fredericksburg 10
Planetary 12 3012 2252
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Feb 8 G0
27 Feb 10 G0
28 Feb 20 G0-G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region on UT day 25-Feb. Mostly G0 geomagnetic conditions were
observed in the Antarctic region, with an isolated period of
G1 observed at Casey. G0 geomagnetic conditions are expected
over 26-27 Feb. G0-G1 geomagnetic conditions are expected on
28-Feb due to coronal hole high speed wind stream effects.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Feb Normal Normal Normal
PCA Event : 10MeV Proton/PCA Event Began at 0010UT 25/02, Ended at 0830UT 25/02
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Feb Normal Normal Normal-fair
27 Feb Normal Normal Normal-fair
28 Feb Normal Normal-fair Fair
COMMENT: HF radio propagation conditions were mostly normal on
UT day 25-Feb. Mostly normal HF conditions are expected over
26-27 Feb, tending to fair at middle and high latitudes on 28-Feb
due to anticipated geomagnetic activity. Shortwave fadeouts are
possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Feb 116
Observed Australian Regional MUFs
Cocos Island Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Enhanced by 25% after local dawn.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jan 124
Feb 118
Mar 115
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
26 Feb 120 Near predicted monthly values
27 Feb 120 Near predicted monthly values
28 Feb 120 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 25 was issued on
25 February and is current for 25-27 Feb. Maximum usable frequencies
(MUFs) on UT day 25-Feb in the Australian region were near predicted
monthly values. Mild spread F was observed at Hobart. MUFs are
expected to be near predicted monthly values over 26-28 Feb.
Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Feb
Daily Proton Fluence >1 MeV: 2.7E+06
Daily Proton Fluence >10 MeV: 6.3E+04
Daily Electron Fluence >2 MeV: 1.60E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C2.4
DSCOVR Satellite Solar Wind Day Averaged Data for 24 Feb
Speed: 359 km/sec Density: 7.3 p/cc Temp: 61400 K Bz: 4 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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