[Ips-dsgr] ASWFC Daily Report - 31 December 23 issued 2330 UT on 31 Dec 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Mon Jan 1 10:30:08 EST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/31 DECEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 31 DECEMBER AND FORECAST FOR 01 JANUARY - 03 JANUARY
STATUS INDICATORS SOL:** RED **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 31 Dec:  R3

Flares    Max     Fadeout    Freq.  Sectors
  M1.0    1913UT  possible   lower  East Pacific/
                                    North American
  X5.0    2155UT  probable   all    East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Dec: 146/100


1B. SOLAR FORECAST
             01 Jan             02 Jan             03 Jan
Activity     R2, chance R3      R2, chance R3      R2, chance R3
Fadeouts     Probable           Probable           Probable
10.7cm/SSN   145/99             140/94             140/94

COMMENT: Solar activity on UT day 31-Dec was at the R3 level 
due to an X5.0 flare at 31/2155UT from AR3536 (N06E76, beta). 
AR3536 is the returning AR3514 which previously produced an X-class 
flare on 14-Dec. There are currently four numbered sunspot regions 
visible on the solar disk. AR3536 recently rotated over the eastern 
limb and is the most significant region on the disk. This region 
likely contains additional spots which are yet to rotate onto 
the visible disk, making its magnetic complexity difficult to 
determine. AR3533 (N15W75, beta) has decayed and will soon rotate 
over the western limb. All other sunspot regions are either stable 
or in decay. Solar activity is expected to be at the R2 level 
over 01-03 Jan, with a chance of further R3 level flares. Several 
CMEs were observed on UT day 31-Dec. A filament eruption was 
observed, visible in H-alpha imagery near N35W55 at 31/0935UT. 
A subsequent CME is visible in LASCO C2 coronagraph imagery from 
31/1000UT. Modelling indicates this CME does not contain a geoeffective 
component. Two additional filament eruptions were observed in 
the southeast quadrant at 31/0509UT and 31/1609UT. These eruptions 
both produced narrow CMEs neither of which are considered to 
be Earth-directed. A west directed CME observed at 31/2000UT 
is considered a farside event. A CME is yet to be observed in 
association with the X5.0 flare. No other Earth-directed CMEs 
have been observed. The solar wind speed on UT day 31-Dec was 
mostly stable, ranging from 305 to 335 km/s and is currently 
near 305 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 8 nT and the north south IMF component (Bz) range was 
+5 to -5 nT. The solar wind speed is expected to increase over 
01-03 Jan due to coronal hole high speed wind stream effects 
from an equatorial coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 31 Dec: G0

Estimated Indices 31 Dec : A   K           
   Australian Region       3   12001112
      Cocos Island         1   01100010
      Darwin               3   11000113
      Townsville           5   12001114
      Learmonth            3   12111102
      Alice Springs        3   12000013
      Gingin               3   12001112
      Canberra             2   01001112
      Hobart               2   12001102    

Estimated Antarctic Regional K Indices 31 Dec :
      Macquarie Island     1   01000002
      Casey               12   23422214
      Mawson               9   23211233

Observed Regional daily pc3 Indices 31 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               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 31 Dec : A 
           Fredericksburg         3
           Planetary              4                         

Observed AFr/Ap Indices 30 Dec :  A   K
           Fredericksburg         4
           Planetary              3   1210 1001     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
01 Jan    10    G0
02 Jan     8    G0
03 Jan     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 31-Dec. G0 geomagnetic conditions 
are expected over 01-03 Jan.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
31 Dec      Normal         Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
01 Jan      Normal         Normal         Normal-fair
02 Jan      Normal         Normal         Normal-fair
03 Jan      Normal         Normal         Normal-fair

COMMENT: HF radio communication conditions on UT day 31-Dec were 
mostly normal. Mostly normal conditions are expected over 01-03 
Jan. Shortwave fadeouts are probable.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
31 Dec   135

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Nov      114
Dec      100
Jan      98

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
01 Jan   130    Near to 15% above predicted monthly values
02 Jan   130    Near to 15% above predicted monthly values
03 Jan   130    Near to 15% above predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 134 was issued on 
31 December and is current for 1-3 Jan. Maximum usable frequencies 
(MUFs) on UT day 31-Dec in the Australian region were near predicted 
monthly values to 15% enhanced. A shortwave fadeout was experienced 
throughout much of the Australian region due to the X5.0 flare 
at 31/2155UT. MUFs are expected to be near predicted monthly 
values to 15% enhanced over 01-03 Jan. Shortwave fadeouts are 
probable.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 30 Dec
       Daily Proton Fluence >1 MeV:   1.8E+05
       Daily Proton Fluence >10 MeV:  1.8E+04
       Daily Electron Fluence >2 MeV: 5.40E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B9.9

DSCOVR Satellite Solar Wind Day Averaged Data for 30 Dec
Speed: 344 km/sec  Density:    5.5 p/cc  Temp:    25200 K  Bz:   2 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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