[Ips-dsgr] ASWFC Daily Report - 04 December 23 issued 2330 UT on 04 Dec 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Tue Dec 5 10:30:08 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/04 DECEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 04 DECEMBER AND FORECAST FOR 05 DECEMBER - 07 DECEMBER
STATUS INDICATORS SOL:GREEN   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 04 Dec:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 04 Dec: 138/92


1B. SOLAR FORECAST
             05 Dec             06 Dec             07 Dec
Activity     R0,chance R1       R0,chance R1       R0,chance R1
Fadeouts     None expected      None expected      None expected
10.7cm/SSN   135/89             130/84             130/84

COMMENT: Solar activity on UT day 04-Dec was at the R0 level 
with the largest flare a minor C8.1 from solar region AR3511(S23E11, 
beta) at 04/0126UT. Solar regions currently on the visible solar 
disk are small to medium in size. Solar region AR3510(S15E11, 
beta) and AR3511 are currently growing. Region AR3500(S19W83, 
beta) that produced an R2 flare on 28-Nov continues to decay 
and is rotating off disk. Small spots have emerged below the 
main spot of region AR3507(N09E05, beta). There are currently 
eight numbered sunspot regions visible on the solar disk. All 
other sunspot regions are stable. Solar activity is expected 
to be at the R0 level over 05-07 Dec, with a slight chance of 
an isolated R1 flare due to the pair of developing solar regions. 
In GONG H-alpha imagery a thin 15 degree long solar filament 
located at S22E10 may have partially lifted off during the interval 
04/0551-0745UT. A smaller 5 degree long filament located at S10W00 
erupted at 04/1638UT. No Earth directed CMEs have been observed 
in the past 24 hours. An east directed CME was observed in LASCO 
C2 from 04/0700UT possibly associated with the earlier filament 
eruption. Event modelling shows an Earth miss, with only a slight 
grazing impact possible on 06-Dec. The solar wind speed on UT 
day 04-Dec was elevated and steady, ranging from 486 to 581 km/s 
and is currently near 560 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 14 nT and the north south IMF component 
(Bz) range was +12 to -9 nT. The IMF Bz component briefly fluctuated 
southward at times during the first half of the UT day. The solar 
wind total field (Bt) was more enhanced later in the UT day possibly 
indicating a weak indistinct CME component transient. The solar 
wind speed is expected to remain elevated 05-06 Dec due to a 
large equatorial coronal hole.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 04 Dec: G0

Estimated Indices 04 Dec : A   K           
   Australian Region      10   23332222
      Cocos Island         5   12321111
      Darwin               9   23332112
      Townsville          11   23432222
      Learmonth           10   23332222
      Alice Springs        8   12332122
      Gingin               8   22332122
      Canberra            11   13432222
      Hobart              11   13432222    

Estimated Antarctic Regional K Indices 04 Dec :
      Macquarie Island    13   13344221
      Casey               36   46654223
      Mawson              22   25534233

Observed Regional daily pc3 Indices 04 Dec : 
      Darwin               6   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              38   (Quiet to unsettled)
      Canberra            34   (Quiet to unsettled)
      Hobart              72   (Active)

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 04 Dec : A 
           Fredericksburg        14
           Planetary             17                         

Observed AFr/Ap Indices 03 Dec :  A   K
           Fredericksburg        10
           Planetary              8   2231 2312     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
05 Dec    18    G0, chance G1
06 Dec    14    G0, chance G1
07 Dec    12    G0

COMMENT: ASWFC Geomagnetic Warning 75 was issued on 3 December 
and is current for 4-5 Dec. G0 geomagnetic conditions were observed 
in the Australian region on UT day 04-Dec. In the Antarctic region 
G1-G2 periods were observed at Casey and G1 periods were observed 
at Mawson. G0, with the chance of G1 periods are expected on 
05-06 Dec due to coronal hole high speed wind stream effects. 
G0 geomagnetic conditions are expected on 07-Dec.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
04 Dec      Normal         Normal         Fair-normal    

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
05 Dec      Normal         Fair-normal    Fair
06 Dec      Normal         Fair-normal    Fair
07 Dec      Normal         Normal         Normal-fair

COMMENT: HF radio communication conditions on UT day 04-Dec were 
normal. Fair to normal HF radio communication conditions are 
expected over 05-06 Dec for middle to high latitudes due to an 
expected mild increase in geomagnetic activity. Mostly normal 
HF conditions are expected on 07-Dec. Isolated minor shortwave 
fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
04 Dec   132

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 15% during local day.
      Enhanced by 20% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Southern Australian Region:
      Near predicted monthly values.
   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
05 Dec    90    Depressed 10 to 15%/near predicted monthly values
06 Dec    95    Depressed 10 to 15%/near predicted monthly values
07 Dec   120    Near predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) were near predicted 
monthly values to 20% enhanced in the Australian region on UT 
day 04-Dec. No significant overnight geomagnetic activity was 
observed on 04-Dec. MUFs are generally expected to be near predicted 
monthly values 05-07 Dec, with brief mild depressions possible 
after local dawn during 05-06 Dec. Isolated minor shortwave fadeouts 
are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 03 Dec
       Daily Proton Fluence >1 MeV:   8.1E+05
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 1.30E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B9.6

DSCOVR Satellite Solar Wind Day Averaged Data for 03 Dec
Speed: 423 km/sec  Density:    7.1 p/cc  Temp:   104000 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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