[Ips-dsgr] ASWFC Daily Report - 11 February 24 issued 2330 UT on 11 Feb 2024 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Mon Feb 12 10:30:56 EST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/11 FEBRUARY 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 11 FEBRUARY AND FORECAST FOR 12 FEBRUARY - 14 FEBRUARY
STATUS INDICATORS SOL:** YELLOW ** MAG:** YELLOW ** ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 11 Feb: R1
Flares Max Fadeout Freq. Sectors
M9.0 10/2307UT probable lower West Pacific
M1.0 2245UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Feb: 180/133
1B. SOLAR FORECAST
12 Feb 13 Feb 14 Feb
Activity Moderate Moderate Moderate
Fadeouts Possible Possible Possible
10.7cm/SSN 182/135 180/133 180/133
COMMENT: Solar activity on UT day 11-Feb was R1, with an M1 solar
flare observed at 11/2245 UT. Also, an M9 level solar flare (R2)
was observed at 10/2300 UT from AR3576 (S17W23, beta-gamma-delta).
There are currently six numbered sunspots on the solar disk.
AR3576 still remains the largest and most magnetically complex,
but it has shown overall decay. This region still maintains at
least one delta spot however and still may have the potential
for X-class solar flares. AR3582 (N06E05, beta) and AR3584 (S16E58,
beta) have also shown noticeable growth over the past day, but
have not yet produced any significant solar flares. Solar activity
is expected to be mostly R1-R2 over 12-14 Feb, with a slight
chance for R3.
An Earth-directed CME was associated with the
M9 solar flare from AR3576 and was first seen at 10/2348 UT.
While the bulk of this CME was deflected to the northwest, an
impact is still expected by 13/1000 UT +/- 12 hours. Two other
CMEs were observed today at 11/0600 UT in the southeast and then
at 11/0800 UT in the southwest. Both of these events are considered
to be farside and not geoeffective.
On UT day 11-Feb a moderate
shock in the solar wind was observed at 0125 UT. This is suspected
to be a glancing blow from the CME that was associated with the
X3 solar flare on 09-Feb, which is considered to have been a
farside event.
The peak total interplanetary field strength (IMF,
Bt) was 20 nT and the north-south IMF component range was +15
to -15 nT. While there were several intermittent periods of southward
oriented Bz, the event was relatively short lived. The solar
wind speed reached a peak of 678 km/s and is currently near 550
km/s.
The solar wind is expected to remain enhanced on 12-Feb,
particularly near the end of the UT day when a CME is expected
to arrive. It is also possible further enhancements may be observed
throughout the day due to the CME associated with the M3 solar
flare on 10-Feb; while this CME was launched from the eastern
limb, it had a similarly wide extent as the X3 associated CME.
Additional to these CMEs is a possible glancing blow from a CME
first observed on 08-Feb, although this is not expected to be
significant. Further enhancements are then expected on 13-Feb
due to the arrival of the CME associated with the M9 solar flare.
Solar wind is expected to begin a return to background levels
on 14-Feb. The 10 MeV protons were at S2 solar radiation storm
levels, but began declining after the CME passed at around 400
UT. The 10 MeV protons reached a peak of 132 pfu, but are now
at S0 levels near 7 pfu. S0 solar radiation storm conditions
are expected over 12-14 Feb, however may fluctuate around the
S1 threshold. It may also see an increase if AR3576 produces further
solar flares.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 11 Feb: G1
Estimated Indices 11 Feb : A K
Australian Region 16 53431312
Cocos Island 13 53331201
Darwin 12 -4331312
Townsville 21 63431322
Learmonth 21 63432312
Alice Springs 16 53431302
Gingin 15 43432322
Canberra 13 43431212
Hobart 13 43432212
Estimated Antarctic Regional K Indices 11 Feb :
Macquarie Island 15 33353211
Casey 44 67543333
Mawson 24 45432344
Observed Regional daily pc3 Indices 11 Feb :
Darwin 0 (Quiet)
Townsville 2 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 6 (Quiet)
Canberra 4 (Quiet)
Hobart 16 (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 11 Feb : A
Fredericksburg 13
Planetary 15
Observed AFr/Ap Indices 10 Feb : A K
Fredericksburg 4
Planetary 4 0111 1102
2B. MAGNETIC FORECAST
Date Ap Conditions
12 Feb 18 G1-G2
13 Feb 26 G2, chance G3
14 Feb 10 G0, chance G1
COMMENT: ASWFC Geomagnetic Warning 5 was issued on 10 February
and is current for 12-13 Feb. The Australian region as a whole
reached G1 geomagnetic conditions on UT day 12-Feb due to the
CME associated with the recent X3 solar flare. Townsville and
Learmonth both recorded a single period of G2. G1-G3 geomagnetic
conditions were observed in Antarctica, and G0 geomagnetic conditions
were observed on the planetary scale.
G0 geomagnetic conditions
are expected initially on 12-Feb, however a shock from a CME
that was associated with an M3 solar flare that was first seen
from 10/0348 UT is possible. While this CME was launched from
the eastern limb, it was very wide, and may have a glancing impact
today. Additionally, G1-G2 geomagnetic conditions may arise due
to another expected impact from a CME that was first seen 10/0724
UT associated with AR3576. Another CME is expected to arrive
near 13/1000 UT +/- 12 hours that was associated with the M9
flare from AR3576. All together, these events may reach G3 geomagnetic
conditions on 13-Feb. Conditions are expected to begin to return
to normal on 14-Feb.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
11 Feb Normal Normal-fair Poor(PCA)
PCA Event : 10MeV Proton/PCA Event Began at 1515UT 09/02, Ended at 1750UT 11/02
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
12 Feb Normal Normal Fair
13 Feb Normal-fair Fair Fair-poor
14 Feb Normal-fair Fair Fair
COMMENT: HF radio communication conditions on UT day 11-Feb were
generally normal at low latitudes. Poor conditions were observed
at high latitudes due to polar cap absorption (PCA), and fair
conditions were observed at middle latitudes. Conditions are
expected to be generally normal at all latitudes at the beginning
of 12-Feb, but may become degraded by the end of the UT day due
to anticipated geomagnetic activity. Degradations are likely
to continue over 13-14 Feb due to further expected geomagnetic
activity. Shortwave fadeouts are possible.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
11 Feb 157
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 15% during local day.
Enhanced by 35% during local night.
Niue Island Region:
Enhanced by 30% during local day.
Enhanced by 35% during local night.
Enhanced by 20% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 35% during local night.
Southern Australian Region:
Near predicted monthly values during local day.
Enhanced by 20% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values over the UT day.
Monthly T index:
Month T index
Jan 144
Feb 108
Mar 108
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
12 Feb 140 Near predicted monthly values to 20% enhanced
13 Feb 115 Near predicted monthly values to 20% depressed
14 Feb 130 Near predicted monthly values to 20% depressed
COMMENT: ASWFC SWF HF Communications Warning 16 was issued on
10 February and is current for 11-12 Feb. ASWFC HF Communications
Warning 17 was issued on 11 February and is current for 11-12
Feb. Maximum usable frequencies (MUFs) on UT day 11-Feb were
near predicted values to 35% enhanced in the Australian region.
A polar cap absorption event has been ongoing since 09/1520 UT
affecting high latitudes, but is expected to end on 12-Feb. Spread-F
was observed at Hobart during local night hours. MUFs are expected
to be near predicted values on 12-Feb, but some enhancements
may be observed at the start of the UT day. MUFs are expected
to be near predicted monthly values to 20% depressed over 13-14
Feb, with the worst depressions likely on 13-Feb due to anticipated
geomagnetic activity. Shortwave fadeouts are possible.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 10 Feb
Daily Proton Fluence >1 MeV: 3.8E+07
Daily Proton Fluence >10 MeV: 1.1E+07
Daily Electron Fluence >2 MeV: 1.80E+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 10 Feb
Speed: 387 km/sec Density: 7.0 p/cc Temp: 58400 K Bz: 1 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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