[Ips-dsgr] ASWFC Daily Report - 25 March 24 issued 2331 UT on 25 Mar 2024 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Tue Mar 26 10:31:05 EST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 MARCH 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 25 MARCH AND FORECAST FOR 26 MARCH - 28 MARCH
STATUS INDICATORS SOL:** RED ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 25 Mar: R1
Flares Max Fadeout Freq. Sectors
M4.4 0644UT possible lower Mid East/Indian
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Mar: 190/143
1B. SOLAR FORECAST
26 Mar 27 Mar 28 Mar
Activity R1-R2, chance R3 R1-R2, chance R3 R1-R2, chance R3
Fadeouts Probable Probable Probable
10.7cm/SSN 195/147 200/152 200/152
COMMENT: Solar activity on UT day 25-Mar was at the R1 level
due to an M4.4 flare at 25/0644UT produced by AR3615 (S13W27,
beta-gamma-delta). There are currently seven numbered sunspot
regions on the solar disk. Most of these are small and magnetically
simple despite some growth in the case of AR3619 (N19E07, beta)
and AR3621 (N15E65, beta). By far the most significant sunspot
region is AR3615 which is large and magnetically complex, with
two visible delta spots, has produced the vast majority of M-class
flares over the previous few days, is currently in a geoeffective
location and continues to show growth. All other sunspot groups
were stable on 25-Mar.
Solar activity over 26-28 Mar is expected
to be at R1-R2 levels, with a chance of R3, predominantly due
to AR3615. S1 solar radiation conditions were observed on 25-Mar
following the S2 event on 23-24 Mar. The >10 MeV proton flux
remains enhanced but in decline. S0 conditions are expected over
26-28 Mar, however there is a chance of S1 conditions, especially
if significant flaring activity occurs from AR3615 as it approaches
the western limb.
No significantly geoeffective CMEs were observed
on UT day 25-Mar. A narrow, west directed CME was observed in
SOHO and STEREO-A imagery from 25/0125UT. Coronal movement over
the western limb is visible from 25/0037UT between S00 and S30
in SDO and GOES SUVI imagery. This CME is considered far side
and not geoeffective. An eruption on the disk at around N12E02
from 25/0737UT is visible in SDO, GOES SUVI and H-Alpha imagery.
However no associated CME is visible in available coronagraph
imagery. A northeast directed CME is visible from 25/1512UT in
SOHO and STEREO-A imagery. This event is associated with an eruption
at around N18E51, visible from 25/1416UT in SDO, GOES SUVI and
H-Alpha imagery. Modelling suggests the majority of the ejecta
from this event will pass behind the Earth, but there is a chance
of a weak glancing impact on 30-Mar at 0100UT +/- 12 hours.
The
solar wind speed was in decline over UT day 25-Mar, ranging from
837 km/s to 583 km/s and is currently at around 610 km/s. The
peak total interplanetary field strength (IMF, Bt) reached 27
nT and the north-south IMF component (Bz) was 23 nT to -13 nT.
Bz was predominantly northward for the entire UT day 25-Mar.
The IMF maximum values were observed in the first part of the
day and have since recovered to a maximum Bt of around 7 nT with
Bz ranging from 6 to -4 nT. The solar wind speed is expected
to continue to decline towards background levels and remain there
over 26-28 Mar as CME and coronal hole high speed wind stream
effects wane.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Mar: G1
Estimated Indices 25 Mar : A K
Australian Region 22 45444321
Darwin 24 55444221
Townsville 32 56454322
Learmonth 31 55455322
Alice Springs 22 45444321
Gingin 22 45444222
Canberra 22 45444321
Kennaook Cape Grim 20 35444320
Hobart 18 35433321
Estimated Antarctic Regional K Indices 25 Mar :
Macquarie Island 29 45454520
Casey 39 66643323
Mawson 27 55543332
Observed Regional daily pc3 Indices 25 Mar :
Darwin 13 (Quiet)
Townsville 30 (Quiet to unsettled)
Learmonth 69 (Active)
Alice Springs 50 (Unsettled)
Gingin NA
Canberra 174 (Severe storm)
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 Mar : A
Fredericksburg 23
Planetary 39
Observed AFr/Ap Indices 24 Mar : A K
Fredericksburg 43
Planetary 93 4344 5984
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Mar 14 G0, chance of G1
27 Mar 8 G0
28 Mar 5 G0
COMMENT: ASWFC Geomagnetic Warning 12 was issued on 23 March
and is current for 24-26 Mar. Geomagnetic conditions in the planetary
and Australian regions were at the G1 level, with a period of
G2 observed at Townsville. Mostly G1 conditions were observed
in the Antarctic region, with G2 conditions observed at Casey.
Geomagnetic conditions eased over the day at all locations. G0
geomagnetic conditions, with a chance of G1 are expected on 26-Mar
as CME and coronal hole high speed wind stream effects wane.
G0 conditions are expected over 27-28 Mar.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Mar Poor-fair Poor-fair Fair-poor
PCA Event : 10MeV Proton/PCA Event Began at 0805UT 23/03, Ended at 1405UT 25/03
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Mar Normal-fair Normal-fair Fair
27 Mar Normal Normal Normal-fair
28 Mar Normal Normal Normal
COMMENT: HF radio communications on UT day 25-Mar were poor to
fair, with the worst conditions observed in the first half of
the UT day as conditions eased over the day. Polar cap absorption
(PCA) contributed to poor conditions in high latitudes for the
first half of the UT day. Mild degradations in HF propagation
conditions are expected on 26-Mar, with the worst conditions
expected in the first part of the day and at higher latitudes.
Conditions are expected to have eased to mostly normal and remain
at this level over 27-28 Mar. Shortwave fadeouts are probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Mar 94
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 20% during local day.
Near predicted monthly values during local night.
Enhanced by 45% after local dawn.
Niue Island Region:
Near predicted monthly values.
Northern Australian Region:
Near predicted monthly values during local day.
Enhanced by 15% during local night.
Southern Australian Region:
Depressed by 25% during local day.
Depressed by 20% during local night.
Depressed by 20% after local dawn.
Antarctic Region (Casey/Davis/Mawson):
Depressed by 30% over the UT day.
Monthly T index:
Month T index
Feb 138
Mar 111
Apr 112
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
26 Mar 100 Near predicted monthly values/depressed 5 to
10%
27 Mar 110 Near predicted monthly values
28 Mar 120 Near predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 31 was issued on
23 March and is current for 24-26 Mar. ASWFC HF Communications
Warning 32 was issued on 24 March and is current for 24-26 Mar.
Maximum usable frequencies (MUFs) on UT day 25-Mar were near
predicted monthly values in the northern Australian region, with
enhancements observed during local night. MUFs in the southern
Australian region were depressed throughout 25-Mar, with some
sign of recovery near the end of the UT-day. Sporadic E was observed
at Brisbane and Canberra and spread F was observed at Canberra
and Hobart, disrupting HF communication conditions. A polar cap
absorption event (PCA) was present in the first half of 25-Mar
and affected ionospheric conditions in the polar regions. MUFs
are expected to be near predicted monthly values over 26-28 Mar,
with mild depressions possible in the southern Australian region
as conditions ease following recent geomagnetic activity. Shortwave
fadeouts are probable.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Mar
Daily Proton Fluence >1 MeV: 1.1E+09
Daily Proton Fluence >10 MeV: 2.6E+07
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: C2.7
DSCOVR Satellite Solar Wind Day Averaged Data for 24 Mar
Speed: 532 km/sec Density: 12.5 p/cc Temp: 311000 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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