[Ips-dsgr] ASWFC Daily Report - 26 April 23 issued 2331 UT on 26 Apr 2023 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Thu Apr 27 09:31:19 EST 2023
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/26 APRIL 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 26 APRIL AND FORECAST FOR 27 APRIL - 29 APRIL
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 26 Apr: R0
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Apr: 137/91
1B. SOLAR FORECAST
27 Apr 28 Apr 29 Apr
Activity R0, chance R1 R0, chance R1 R0, chance R1
Fadeouts Possible Possible Possible
10.7cm/SSN 135/89 135/89 135/89
COMMENT: Solar activity on UT day 26-Apr was at the R0 level.
There are currently 3 numbered sunspot regions on the solar disk.
Regions AR3285 (S19E06, beta) and AR3287 (S25E39, alpha) have
shown some growth over the 24 hour period. A new region has rotated
onto the disk near N20E58 but is yet to be classified. All other
sunspot regions are either stable or in decay. Solar activity
is expected to be at predominantly R0 levels over 27-29 Apr,
with a chance of R1. A faint CME was observed from the SW quadrant
following a filament eruption on 25/1933UT, but is not expected
to be geoeffective. Several filament eruptions were observed
on 26-Apr: in the southwest from 0537UT, in the northeast from
0625UT and in the northwest from 0937UT. CMEs were observed following
all of these filament eruptions, but none are considered geoeffective.
No other CMEs were observed. The solar wind speed on UT day 26-Apr
was on a general inclining trend and ranged between 504 to 701
km/s, and is currently near 650 km/s. The peak total interplanetary
field strength (IMF, Bt) was 10 nT and the north-south IMF component
range was +8 to -7 nT. The solar wind speed is expected to be
elevated over 27-28 due to an equatorial coronal hole high speed
wind stream, with further enhancements from an anticipated impact
from a CME on 27-Apr. Solar wind speeds may begin to decline
on 29-Apr.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 26 Apr: G1
Estimated Indices 26 Apr : A K
Australian Region 12 22234332
Cocos Island 8 22123321
Darwin 11 22234322
Townsville 12 22234332
Learmonth 16 22245332
Alice Springs 12 21234332
Gingin 15 22235332
Canberra 9 12233322
Hobart 11 22234322
Estimated Antarctic Regional K Indices 26 Apr :
Macquarie Island 26 23356432
Casey 15 33334332
Mawson 27 34543453
Observed Regional daily pc3 Indices 26 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 2 (Quiet)
Gingin 22 (Quiet to unsettled)
Canberra 29 (Quiet to unsettled)
Hobart 44 (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 26 Apr : A
Fredericksburg 11
Planetary 13
Observed AFr/Ap Indices 25 Apr : A K
Fredericksburg 7
Planetary 8 2011 2233
2B. MAGNETIC FORECAST
Date Ap Conditions
27 Apr 20 G0-G1
28 Apr 14 G0-G1
29 Apr 10 G0
COMMENT: Mostly G0 geomagnetic conditions were observed in the
Australian region on UT day 26-Apr, with isolated periods of
G1 observed at Learmonth and Gingin. Mostly G0-G1 geomagnetic
conditions were observed in the Antarctic region, with a period
of G2 observed at Macquarie Island. G0-G1 geomagnetic conditions
are expected over 27-28 Apr due to the combination of an equatorial
coronal hole high speed wind steam and anticipated CME impact.
Mostly G0 geomagnetic conditions are expected on 29-Apr.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
26 Apr Normal-fair Normal-fair Fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
27 Apr Normal-fair Fair Fair
28 Apr Normal-fair Fair Fair
29 Apr Normal Normal Normal-fair
COMMENT: Mildly degraded HF propagation conditions were observed
in the Australian region on 26-Apr, primarily due to sporadic-E
at most sites. Mildly degraded HF propagation conditions are
expected over 27-28 Apr due to anticipated geomagnetic activity,
with normal conditions expected by 29-Apr.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
26 Apr 99
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 50% during local day.
Enhanced by 20% during local night.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Enhanced by 20% during local day.
Near predicted monthly values during local night.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Near predicted monthly values 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
27 Apr 90 Near predicted monthly values to 15% depressed
28 Apr 85 Near predicted monthly values to 15% depressed
29 Apr 85 Near predicted monthly values
COMMENT: Maximum usable frequencies (MUFs) on UT day 26-Apr in
the Australian region were enhanced by 20% in the northern region
in local day time, and near predicted monthly values otherwise.
Sporadic-E was observed at most sites during local night hours.
Spread F was observed at Hobart. MUFs are expected to be near
predicted monthly values to 15% depressed over 27-28 Apr due
to anticipated geomagnetic activity. MUFs are expected to be
near predicted values on 29-Apr.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 25 Apr
Daily Proton Fluence >1 MeV: 1.1E+06
Daily Proton Fluence >10 MeV: 2.2E+04
Daily Electron Fluence >2 MeV: 1.30E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B6.1
DSCOVR Satellite Solar Wind Day Averaged Data for 25 Apr
Speed: 527 km/sec Density: 9.2 p/cc Temp: 385000 K Bz: 0 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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