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

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Tue Dec 24 10:30:49 AEDT 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/23 DECEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 23 DECEMBER AND FORECAST FOR 24 DECEMBER - 26 DECEMBER
STATUS INDICATORS SOL:** RED **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 23 Dec:  R2

Flares    Max     Fadeout    Freq.  Sectors
  M1.0    0231UT  possible   lower  E. Asia/Aust.
  M1.0    0629UT  possible   lower  Mid East/Indian
  M9.0    1112UT  probable   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Dec: 238/187


1B. SOLAR FORECAST
             24 Dec             25 Dec             26 Dec
Activity     R1-R2, chance R3   R1-R2, chance R3   R1-R2, chance R3
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   230/180            230/180            230/180

COMMENT: Solar activity on UT day 23-Dec was R2, with an isolated 
M8.9 solar flare from AR3928 (S08E05, beta-gamma). There are 
currently seven numbered sunspots on the disk, with several being 
highly complex regions. AR3927 (S03E05, beta-gamma) and AR3928 
have grown over the past day, and AR3932 (S12E30, beta-gamma) 
appears unstable. Other sunspots are either stable or in decay. 
Solar activity is expected to be R1-R2 with a slight chance for 
R3 over 24-26 Dec. 

A partial halo CME was observed from 23/1136 
UT. This CME was associated with the M8.9 flare near S10E20, although 
was directed relatively southward. This CME is expected to have an Earth
 arrival from either late 25-Dec or early 26-Dec UT day, however given 
limited available imagery analysis of this event was limited.

 S0 solar radiation storm conditions were observed on UT day 23-Dec, 
with the 10 MeV protons peaking at 4.17 pfu. S0-S1 solar radiation 
storm conditions are expected over 24-26 Dec.

 The solar wind environment was mostly undisturbed on UT day 23-Dec. The solar 
wind speed ranged from 485 to 630 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 7 nT and the north-south IMF component 
range (Bz) was +4 to -6 nT. The solar wind speed may remain elevated 
in the next 24 hours due to a small coronal hole wind stream. 
The solar wind may become mildly disturbed on UT day 24-Dec due 
to two possible CME glancing blows. A further, likely stronger, 
disturbance is expected at the end of UT day 25-Dec or early 
26-Dec.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 23 Dec: G0

Estimated Indices 23 Dec : A   K           
   Australian Region      10   32212333
      Cocos Island         6   21112322
      Darwin               8   22112323
      Townsville          10   32212333
      Learmonth           10   32212333
      Alice Springs        8   31102323
      Gingin              10   32212333
      Canberra            10   31212333
      Kennaook Cape Grim  10   31212333
      Hobart              10   32212333    

Estimated Antarctic Regional K Indices 23 Dec :
      Macquarie Island     9   12213422
      Casey               34   45644434
      Mawson              24   44424444

Observed Regional daily pc3 Indices 23 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             4   (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 Dec : A 
           Fredericksburg         9
           Planetary             11                         

Observed AFr/Ap Indices 22 Dec :  A   K
           Fredericksburg        15
           Planetary             11   1113 3333     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
24 Dec    16    G0-G1
25 Dec    20    G1-G2
26 Dec    14    G0-G1, chance G2

COMMENT: G0 geomagnetic conditions were observed on UT day 23-Dec 
in the Australian region. G1-G2 geomagnetic conditions were observed 
in the Antarctic regions. G0-G1 geomagnetic conditions are expected 
on 24-Dec due to two possible CME glancing blows. G1-G2 geomagnetic 
conditions are possible by the end of UT day 25-Dec or early 
26-Dec due to a CME launched on 23-Dec.

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

PCA Event : No event.

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

COMMENT: HF radio propagation conditions were fair to poor at 
high latitudes due to ongoing polar cap absorption (PCA). Conditions 
were generally normal at mid to low latitudes. PCA is expected 
to continue over 24-25 Dec, but ease towards normal conditions. 
HF propagation may become degraded due to expected geomagnetic 
activity though over 24-26 Dec, with harshest degradations during 
local night hours. Shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
23 Dec   114

Observed Australian Regional MUFs
   Cocos Island Region:
      Mostly near predicted monthly values.
   Niue Island Region:
      Mostly near predicted monthly values.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed by 15% over the UT day.

Monthly T index:
Month  T index
Nov      127
Dec      117
Jan      114

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
24 Dec   120    Near predicted monthly values to 10-15% depressed
25 Dec   115    Near predicted monthly values to 10-15% depressed
26 Dec   105    Near predicted monthly values to 15% depressed

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 23-Dec were mostly near predicted values. Sporadic 
E was common at most sites during local night hours. Polar cap 
absorption affected mid to high latitudes. MUFs are expected 
to be near predicted values to 15% depressed over 24-26 Dec due 
to multiple CME impacts expected. Sporadic E is expected to continue.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 22 Dec
       Daily Proton Fluence >1 MeV:   9.4E+05
       Daily Proton Fluence >10 MeV:  3.4E+05
       Daily Electron Fluence >2 MeV: 2.40E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 4%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C2.2

DSCOVR Satellite Solar Wind Day Averaged Data for 22 Dec
Speed: 590 km/sec  Density:    1.2 p/cc  Temp:   237000 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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