[Ips-dsgr] ASWFC Daily Report - 23 March 24 issued 2330 UT on 23 Mar 2024 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sun Mar 24 10:30:56 EST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 MARCH 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 MARCH AND FORECAST FOR 24 MARCH - 26 MARCH
STATUS INDICATORS SOL:** RED **   MAG:** RED **     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Mar:  R3

Flares    Max     Fadeout    Freq.  Sectors
  X1.1    0134UT  probable   all    West Pacific
  M1.2    0434UT  possible   lower  E. Asia/Aust.
  M1.1    0655UT  possible   lower  Mid East/Indian
  M2.4    0709UT  possible   lower  Mid East/Indian
  M3.1    0739UT  possible   lower  Mid East/Indian
  M1.0    1129UT  possible   lower  European
  M1.3    1247UT  possible   lower  European
  M1.9    1337UT  possible   lower  European
  M5.2    1352UT  possible   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Mar: 209/160


1B. SOLAR FORECAST
             24 Mar             25 Mar             26 Mar
Activity     R1-R2, chance R3   R1-R2, chance R3   R1-R2 chance, R3
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   210/161            210/161            210/161

COMMENT: Solar activity on UT day 23-Mar reached R3, with a long 
duration X1 level solar flare from both AR3615 (S12W01, beta-gamma-delta) 
and AR3614 (N21W04) from 23/0132 UT contributing to the Xray 
flux. Approximately eleven other R1-R2 level solar flares were 
observed with AR3615. AR3615 is currently the most complex sunspot 
region on the solar disk and has a high potential for solar activity. 
This region has grown significantly in the past 24 hours. AR3617 
(S15E29, alpha) has also shown some minor growth over the past 
day, otherwise all other sunspot regions are stable. Solar activity 
is expected to be R1-R2 with a chance for R3 over 24-26 Mar. 


A full halo CME was observed at 23/0125 UT. The source of the 
CME may be from near AR3614, of which significant coronal dimming 
can be observed as well as post flare arcades. A secondary CME 
may also have been launched from AR3615 shortly after, although 
it is difficult to distinguish in available imagery. This CME 
activity has been modelled and is expected to impact Earth near 
the end of UT day 24-Mar to early 25-Mar. No other CMEs were 
observed on 23-Mar. 

An increase to the 10 MeV, 50 MeV and 100 
MeV protons was observed associated with the X1 solar flare. 
The 10 MeV protons have reached a peak of 956 pfu, slightly under 
the S3 solar radiation storm threshold. At time of writing, an 
S2 solar radiation storm is ongoing. S2, declining to S1 solar 
radiation storm conditions are expected over 24-25 Mar.

 Earth 
fell under influence of a coronal hole wind stream on 23-Mar. 
The solar wind speed reached a maximum of 509 km/s and is currently 
near 500 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 17 nT and the north-south IMF component (Bz) range was 
+11 to -14 nT. Several periods of sustained southward Bz were 
observed on 23-Mar. The solar wind is expected to remain elevated 
from the coronal hole on 24-Mar, followed by a further increase 
due to the expected CME arrival. Solar wind speeds are expected 
to be elevated on 25-Mar, declining by 26-Mar.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 23 Mar: G1

Estimated Indices 23 Mar : A   K           
   Australian Region      20   34234344
      Darwin              18   34234334
      Townsville          24   34245344
      Learmonth           25   33245345
      Alice Springs       19   33235334
      Gingin              20   33234444
      Canberra            21   34334344
      Kennaook Cape Grim  22   34334444
      Hobart              21   34333444    

Estimated Antarctic Regional K Indices 23 Mar :
      Macquarie Island    29   34543544
      Casey               21   44333434
      Mawson              35   25632455

Observed Regional daily pc3 Indices 23 Mar : 
      Darwin               2   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             8   (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 23 Mar : A 
           Fredericksburg        19
           Planetary             29                         

Observed AFr/Ap Indices 22 Mar :  A   K
           Fredericksburg        10
           Planetary              9   3333 1111     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
24 Mar    30    G1 initially, then G2-G3 with a slight chance 
                of G4
25 Mar    40    G2-G3 with a slight chance of G4
26 Mar    20    G1-G2

COMMENT: ASWFC Geomagnetic Warning 11 was issued on 23 March 
and is current for 25-26 Mar. G0-G1 geomagnetic conditions were 
observed in the Australian region on UT day 23-Mar, with mostly 
the low latitude sites experiencing G1 geomagnetic conditions. 


G1 geomagnetic conditions are expected to continue at the beginning 
of UT day 24-Mar due to ongoing coronal hole high speed wind 
stream effects. G2-G3 geomagnetic conditions with a slight chance 
of G4 are expected by the end of 24-Mar leading into the beginning 
of 25-Mar. These conditions are expected to ease to G1-G2 by 
26-Mar.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
23 Mar      Normal         Normal-fair    Poor(PCA)      

PCA Event : 10MeV Proton/PCA Event Began 23 03 2024 0805UT and is in progress

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
24 Mar      Normal-fair    Fair           Poor(PCA)
25 Mar      Fair           Poor-fair      Poor
26 Mar      Fair           Fair           Poor-fair

COMMENT: HF radio communication conditions on UT day 23-Mar were 
mostly normal in low latitudes, normal to fair in middle latitudes 
and poor in high latitudes due to a polar cap absorption (PCA) 
event.

 The PCA event is expected to continue over 24-25 Mar, 
such that HF conditions in high latitudes are expected to be 
poor. In addition, HF conditions are expected to be fair to poor 
over 24-26 Mar due to expected geomagnetic activity. Shortwave 
fadeouts are probable.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
23 Mar   129

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 25% during local day.
      Enhanced by 50% during local night.
   Niue Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Enhanced by 20% after local dawn.
   Southern Australian Region:
      Mostly near predicted monthly values.
      Depressed by 20% after local dawn.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 20% over the UT day.
      Proton event in progress, increased absorption observed.

Monthly T index:
Month  T index
Feb      138
Mar      111
Apr      112

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
24 Mar    90    Near predicted monthly values initially, then 
                depressed 20-30%
25 Mar    80    Depressed 20-30%
26 Mar    75    Depressed 20-30%, possibly returning to near 
                predicted monthly values

COMMENT: ASWFC Preliminary HF Communications Warning 30 was issued 
on 23 March and is current for 25-26 Mar. ASWFC SWF HF Communications 
Warning 31 was issued on 23 March and is current for 24-26 Mar. 
Maximum usable frequencies (MUFs) in the Australian region on 
UT day 23-Mar were near predicted values mostly; with some depressions 
in the southern regions and enhancements in the northern regions. 
Spread-F was observed at southern Australian sites such as Hobart 
and Perth. A HF fadeout may have affected lower frequencies of 
radio communication between 23/0108 - 0512 UT in the Australian 
region, with the most impacts likely around 0134 UT. 

MUFs are 
expected to become depressed by 20-30% by the beginning of UT 
day 25-Mar, with depressions continuing over 25-26 Mar due to 
current and expected geomagnetic activity. Shortwave fadeouts 
are probable.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 22 Mar
       Daily Proton Fluence >1 MeV:   7.0E+04
       Daily Proton Fluence >10 MeV:  1.8E+04
       Daily Electron Fluence >2 MeV: 9.20E+05   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C2.2

DSCOVR Satellite Solar Wind Day Averaged Data for 22 Mar
Speed: 354 km/sec  Density:    5.1 p/cc  Temp:    25400 K  Bz:   4 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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