[Ips-dsgr] ASWFC Daily Report - 25 April 23 issued 2330 UT on 25 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Wed Apr 26 09:30:11 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 APRIL AND FORECAST FOR 26 APRIL - 28 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Apr: 131/85
1B. SOLAR FORECAST
26 Apr 27 Apr 28 Apr
Activity R0 R0, chance of R1 R0, chance of R1
Fadeouts None expected Possible Possible
10.7cm/SSN 130/84 130/84 130/84
COMMENT: Solar activity on UT day 25-Apr was at the R0 level.
There are currently four numbered sunspots regions visible on
the solar disk and one unnumbered region. AR3288 (S23E27, beta)
has recently appeared on the solar disk and displayed development
over the UT day. An unnumbered region appeared on 25-Apr at around
N15E10 with beta magnetic characteristics. All other sunspot
regions are either stable or in decay. Solar activity is expected
to be at the R0 level over 26-28 Apr, with a chance of R1 on
27-28 Apr. No Earth directed CMEs were observed. A NE directed
CME was observed from 25/1012UT in LASCO C2 and STEREO-A imagery.
No associated on disk activity was observed and this is considered
a far-side event. Two filament liftoffs were visible over the
UT day. One at around W50N50 from 25/0521UT, visible in GOES
SUVI, SDO and H-alpha imagery. No associated CME is visible following
this liftoff. A second liftoff was observed at around W20S40
from 25/1933UT in GOES SUVI, SDO and H-alpha imagery. No associated
CME is visible in currently available coronagraph imagery. Further
analysis will be performed when more imagery is available. The
solar wind speed was elevated over 25-Apr, with an increase over
the first two hours of the UT day. The wind speed ranged from
472 to 575 km/s and is currently at around 520 km/s. The peak
total interplanetary field strength (IMF, Bt) was 9 nT and the
north-south IMF component (Bz) range was +8 to -5 nT. The solar
wind speed is expected to increase on 26-Apr and remain elevated
over 27-28 Apr due to high speed wind stream effects from an
equatorial coronal hole rotating into a geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Apr: G0
Estimated Indices 25 Apr : A K
Australian Region 7 21113232
Cocos Island 5 11112231
Darwin 7 21113232
Townsville 8 21123232
Learmonth 9 31213232
Alice Springs 7 20113232
Gingin 6 20103232
Canberra 6 20113222
Hobart 6 11113231
Estimated Antarctic Regional K Indices 25 Apr :
Macquarie Island 7 20004232
Casey 13 33323242
Mawson 21 21222356
Observed Regional daily pc3 Indices 25 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 4 (Quiet)
Hobart 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 Apr : A
Fredericksburg 7
Planetary 9
Observed AFr/Ap Indices 24 Apr : A K
Fredericksburg 39
Planetary 72 7876 3334
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Apr 15 G0, chance of G1
27 Apr 20 G0-G1
28 Apr 12 G0, chance of G1
COMMENT: G0 geomagnetic conditions were observed in the Australian
region. Mostly G0 conditions were observed in the Antarctic region,
with periods of G1 and G2 at Mawson. G0 geomagnetic conditions,
with a chance of G1 are expected on 26-Apr due to coronal hole
high speed wind stream effects. G0-G1 conditions are expected
on 27-Apr due to a combination of ongoing high speed wind stream
effects and an anticipated glancing CME impact at around 27/0800UT
+/- 12 hours. G0 conditions, with a chance of G1 are expected
on 28-Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Apr Normal-fair Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Apr Normal Normal Normal-fair
27 Apr Normal Normal-fair Fair
28 Apr Normal Normal Normal-fair
COMMENT: Mostly normal HF propagation conditions were observed
in the Southern Hemisphere over 24-Apr. Mostly poor HF propagation
conditions were observed in the Northern Hemisphere over 24-Apr.
Mostly normal HF propagation conditions are expected over 26-28
Apr, with degradations possible over 27-28 Apr due to geomagnetic
activity.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Apr 103
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 30% during local day.
Enhanced by 70% during local night.
Niue Island Region:
Enhanced by 20% during local day.
Enhanced by 45% during local night.
Northern Australian Region:
Enhanced by 25% during local day.
Near predicted monthly values during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Depressed by 15% during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Depressed by 15% 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
26 Apr 110 Near to 15% above predicted monthly values
27 Apr 100 Near to 15% above predicted monthly values
28 Apr 90 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 25-Apr in
the Australian region were enhanced by up to 25% in the Northern
Australian region and 20% in the Southern Australian region during
local day. Sporadic E was observed at Learmonth during local
night. Spread F was observed at Hobart during local night. MUFs
are expected to be near predicted monthly values to 15% enhanced
over 26-28 Apr. Mild depressions are possible over 27-28 Apr
due to geomagnetic activity.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Apr
Daily Proton Fluence >1 MeV: 1.4E+07
Daily Proton Fluence >10 MeV: 2.6E+04
Daily Electron Fluence >2 MeV: 9.40E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B5.4
DSCOVR Satellite Solar Wind Day Averaged Data for 24 Apr
Speed: 528 km/sec Density: 8.8 p/cc Temp: 344000 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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