[Ips-dsgr] ASWFC Daily Report - 19 December 24 issued 2330 UT on 19 Dec 2024 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri Dec 20 10:30:50 AEDT 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 DECEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 DECEMBER AND FORECAST FOR 20 DECEMBER - 22 DECEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Dec:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.6    1038UT  possible   lower  European
  M3.8    1534UT  possible   lower  South American/
                                    Atlantic
  M1.7    1900UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Dec: 175/129


1B. SOLAR FORECAST
             20 Dec             21 Dec             22 Dec
Activity     R0-R1, chance R2   R0-R1, chance R2   R0-R2, chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   175/129            180/133            180/133

COMMENT: Solar activity on UT day 19-Dec was R1, with three low-level 
M-class solar flares. The highest flare of the day was M3.7, 
which originated from new region AR3928 (S11E63, beta). There 
are currently five numbered sunspots on the disk. AR3927 (S08E59, 
beta) and AR3928 have grown over the past day as it has rotated 
into view. AR3922 (S20W50, beta) has been mostly stable despite 
releasing two M1 flares. All other sunspot regions are stable. 
Solar activity is expected to be R0-R1, with a chance for isolated 
R2 flares. 

A CME was observed directed to the solar southwest 
from 19/1448 UT, but has been analysed as a farside event. No 
other noteworthy CMEs were observed on UT day 19-Dec. 

S0 solar radiation storm conditions were observed on UT day 19-Dec. S0 
solar radiation storm conditions are expected over 20-22 Dec. 

The solar wind environment on UT day 19-Dec was mostly undisturbed. 
The solar wind was on a decline and ranged from near 600 to 400 
km/s. The peak total interplanetary field strength (IMF, Bt) 
was 6 nT and the north-south IMF component (Bz) was +5 to -6 
nT. The solar wind is expected to be near background conditions 
over 20-22 Dec.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 19 Dec: G0

Estimated Indices 19 Dec : A   K           
   Australian Region       6   32211122
      Cocos Island         4   22111021
      Darwin               6   32111122
      Townsville           6   32112122
      Learmonth            6   32211122
      Alice Springs        5   32101112
      Gingin               6   32211022
      Canberra             6   32201122
      Kennaook Cape Grim   9   322-----
      Hobart               9   32312123    

Estimated Antarctic Regional K Indices 19 Dec :
      Macquarie Island     5   22212112
      Casey               33   56633133
      Mawson              25   54433235

Observed Regional daily pc3 Indices 19 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               2   (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 19 Dec : A 
           Fredericksburg         9
           Planetary             10                         

Observed AFr/Ap Indices 18 Dec :  A   K
           Fredericksburg        12
           Planetary             12   3123 3331     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
20 Dec     5    G0
21 Dec     5    G0
22 Dec     5    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 19-Dec. G0-G2 geomagnetic conditions were observed 
in the Antarctic region. G0 geomagnetic conditions are expected 
over 20-22 Dec.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
19 Dec      Normal-fair    Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
20 Dec      Normal         Normal         Normal
21 Dec      Normal         Normal         Normal
22 Dec      Normal         Normal         Normal

COMMENT: HF radio propagation conditions were mildly degraded 
at the start of the UT day, with improving conditions throughout 
the day. HF radio propagation conditions are expected to be mostly 
normal over 20-22 Dec. Shortwave fadeouts are possible.

-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
19 Dec   111

Observed Australian Regional MUFs
   Cocos Island Region:
      Depressed by 35% during local day.
      Depressed by 25% during local night.
   Niue Island Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values 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
20 Dec   110    Near predicted monthly values to 15% enhanced
21 Dec   115    Near predicted monthly values to 20% enhanced
22 Dec   120    Near predicted monthly values to 20% enhanced

COMMENT: ASWFC SWF HF Communications Warning 145 was issued on 
18 December and is current for 18-20 Dec. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 19-Dec were mostly 
near predicted monthly values. Sporadic-E was common at most 
sites during local night hours. Darwin and Learmonth were degraded 
during local daylight and night hours. MUFs are expected to be 
near predicted values and up to 15-20% enhanced over 20-22 Dec.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 18 Dec
       Daily Proton Fluence >1 MeV:   1.3E+06
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 5.50E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.7

DSCOVR Satellite Solar Wind Day Averaged Data for 18 Dec
Speed: 516 km/sec  Density:    2.8 p/cc  Temp:   216000 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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