[Ips-dsgr] ASWFC Daily Report - 21 March 24 issued 2330 UT on 21 Mar 2024 [SEC=OFFICIAL]
Regional Warning Centre
rwc at ips.gov.au
Fri Mar 22 10:30:09 EST 2024
SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 MARCH 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 21 MARCH AND FORECAST FOR 22 MARCH - 24 MARCH
STATUS INDICATORS SOL:** RED ** MAG:GREEN ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 21 Mar: R0
Flares Max Fadeout Freq. Sectors
M2.0 20/2255UT possible lower East Pacific/
North American
Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Mar: 197/149
1B. SOLAR FORECAST
22 Mar 23 Mar 24 Mar
Activity R1-R2 R1-R2 R1-R2
Fadeouts Probable Probable Probable
10.7cm/SSN 180/133 178/131 174/128
COMMENT:
Solar activity on UT day 21-Mar was at the R0 level with the largest
flare being a C8.7 flare at 21/1132UT from AR3615 (S12E20, beta-gamma-delta).
A long duration C5.8 flare was also observed at 21/1819UT.
There are currently eight numbered active regions visible on the solar
disk and two unnumbered regions. AR3615 is the largest and most magnetically
complex visible region and showed spot development over 21-Mar. Newly
numbered region AR3618 (S20W61, beta) also showed spot development over
the UT day. All other numbered regions are stable. An unnumbered region
has appeared on the solar disk at around N18W08 with beta magnetic complexity,
a further unnumbered region has rotated on at around N20E60, also with
beta magnetic complexity.
Solar activity is expected to be at R1-R2 levels over 22-24 Mar.
No significantly Earth-directed CMEs were observed on 21-Mar. Several CMEs
were observed over the UT day, however many were clearly far-side events.
A fast, south directed CME is visible from 20/1736UT in SOHO imagery, associated
with a filament lift off discussed in yesterday's forecast. Analysis of
this event is difficult due to lack of available imagery, however it is not
considered geoeffective. A filament lift off is visible in SDO, H-Alpha and
GOES SUVI imagery from 21/1806UT at around S35W65. No associated CME is
visible in currently available imagery, any resulting CME will be analysed
once imagery becomes available. A fast, north-directed CME is visible from
21/1836UT in SOHO imagery. This CME is associated with an eruption at around
N30E30 from 21/1746UT visible in SDO, H-Alpha and GOES SUVI imagery, associated
with the long duration C5.8 flare at 21/1819UT. Very limited imagery is
currently available for this CME and further analysis will be performed once
more imagery becomes available. This CME is unlikely to be significantly
geoeffective.
A shock in the solar wind was observed at 21/0152UT resulting in a jump in
solar wind speed. The speed remained steady but varied for the rest of the UT
day. The solar wind speed ranged from 305 km/s to 383 km/s and is currently at
around 361 km/s. The peak total interplanetary field strength (IMF, Bt) was
15 nT and the north south IMF component (Bz) range was +11 to -12 nT. Two
periods
of extended significantly southward Bz were observed on 21-Mar. The first was
from 21/1103UT to 21/1335UT, the second began at 21/1516UT and is ongoing. Both
the shock in the solar wind speed and the periods of southward Bz are due to a
glancing impact from a CME first observed on 17-Mar.
The solar wind speed is expected to remain at current levels or decline slightly
over the majority of 22-23 Mar. An increase is expected late on 23-Mar or on
24-Mar
due to high speed wind stream effects from an equatorial coronal hole rotating
towards a geoeffective position.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 21 Mar: G0
Estimated Indices 21 Mar : A K
Australian Region 14 33224333
Darwin 14 43223333
Townsville 18 43334333
Learmonth 16 43223334
Alice Springs 13 33223333
Gingin 17 32223345
Canberra 14 33224333
Kennaook Cape Grim 16 32324343
Hobart 16 32324343
Estimated Antarctic Regional K Indices 21 Mar :
Macquarie Island 29 22336553
Casey 21 44433334
Mawson 36 33324475
Observed Regional daily pc3 Indices 21 Mar :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 5 (Quiet)
Canberra 3 (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 21 Mar : A
Fredericksburg 19
Planetary 26
Observed AFr/Ap Indices 20 Mar : A K
Fredericksburg 3
Planetary 5 2010 1223
2B. MAGNETIC FORECAST
Date Ap Conditions
22 Mar 12 G0, chance of G1
23 Mar 8 G0
24 Mar 15 G0, chance of G1
COMMENT: G1 geomagnetic conditions were observed at the planetary
level on UT day 21-Mar. Mostly G0 conditions were observed in
the Australian region, with a period of G1 observed at Gingin.
A weak impulse of 16nT was observed at 21/0250UT. Mostly G0 conditions
were observed in the Antarctic region, with G2 conditions observed
at Macquarie Island and G3 conditions observed at Mawson. This
geomagnetic activity was due to a glancing impact from a CME
first observed on 17-Mar. G0 geomagnetic conditions, with a chance
of G1 are expected on 22-Mar due to ongoing CME effects. G0 conditions
are expected on 23-Mar, G0 conditions with a chance of G1 are
expected on 24-Mar due to high speed wind stream effects from
an equatorial coronal hole rotating towards a geoeffective position.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
21 Mar Normal-fair Normal-fair Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
22 Mar Normal-fair Normal-fair Normal-fair
23 Mar Normal Normal Normal-fair
24 Mar Normal Normal Normal-fair
COMMENT: HF radio communication conditions on UT day 21-Mar were
mostly normal, with some degraded conditions observed in the
southern hemisphere from 21/2000UT. Normal to fair conditions
are expected on 22-Mar due to ongoing geomagnetic activity, with
fair conditions most likely at high latitudes. HF radio communication
conditions are expected to be mostly normal over 23-24 Mar. Shortwave
fadeouts are probable.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
21 Mar 138
Observed Australian Regional MUFs
Cocos Island Region:
Enhanced by 20% during local day.
Near predicted monthly values during local night.
Niue Island Region:
Mostly near predicted monthly values.
Depressed by 20% after local dawn.
Northern Australian Region:
Enhanced by 15% during local day.
Enhanced by 25% during local night.
Southern Australian Region:
Enhanced by 20% during local day.
Enhanced by 15% during local night.
Antarctic Region (Casey/Davis/Mawson):
Near predicted monthly values 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
22 Mar 125 Near predicted monthly values
23 Mar 135 Near to 15% above predicted monthly values
24 Mar 135 Near to 15% above predicted monthly values
COMMENT: ASWFC SWF HF Communications Warning 28 was issued on
20 March and is current for 20-22 Mar. Maximum usable frequencies
(MUFs) in the Australian region on UT day 21-Mar were enhanced
for the majority of the UT day, with the strongest enhancements
observed in the northern Australian region during local night.
Brief depressions of up to 10% were observed during local dawn
in the southern Australian region due to recent and ongoing geomagnetic
activity. MUFs are expected to be near predicted monthly values
on 22-Mar. MUFs are expected to be near predicted monthly values
to 15% enhanced over 23-24 Mar. Shortwave fadeouts are probable.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 20 Mar
Daily Proton Fluence >1 MeV: 2.3E+05
Daily Proton Fluence >10 MeV: 2.1E+04
Daily Electron Fluence >2 MeV: 1.20E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: C1.4
DSCOVR Satellite Solar Wind Day Averaged Data for 20 Mar
Speed: 345 km/sec Density: 3.7 p/cc Temp: 46600 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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