[Ips-dsgr] ASWFC Daily Report - 18 December 24 issued 2330 UT on 18 Dec 2024 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Thu Dec 19 10:30:48 AEDT 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/18 DECEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 18 DECEMBER AND FORECAST FOR 19 DECEMBER - 21 DECEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: ** YELLOW **
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 18 Dec:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Dec: 174/128


1B. SOLAR FORECAST
             19 Dec             20 Dec             21 Dec
Activity     R0-R1, chance R2   R0-R1, chance R2   R0-R1, chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   175/129            185/138            190/143

COMMENT: Solar activity on UT day 18-Dec was R0, with no significant 
solar flares. There are currently four numbered sunspot regions 
on the solar disk. AR3922 (S19WW37, beta-gamma) and AR3924 (S19W65, 
beta) have shown some consolidation in their spots. All other 
sunspot regions are either stable or in decay. Solar activity 
is expected to be R0-R1, chance R2 over 19-21 Dec. 

S0 solar radiation storm conditions were observed on UT day 18-Dec.
 S0 solar radiation storm conditions are expected over 19-21 Dec. 

No CMEs were observed on UT day 18-Dec. 

The solar wind speed on UT day 18-Dec was generally 
undisturbed, with lingering CME effects at the beginning
of the day. The peak total interplanetary field strength (IMF, 
Bt) was 13 nT and the north-south IMF component range (Bz) was 
+6 to -8 nT. The solar wind speed ranged between 548 to 722 as 
reported by the ACE satellite, but is expcted to begin to decline 
to near background conditions on 19-Dec and over 20-21 Dec.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 18 Dec: G0

Estimated Indices 18 Dec : A   K           
   Australian Region      12   32323332
      Cocos Island         9   32222330
      Darwin               8   21223322
      Townsville          12   32323332
      Learmonth           12   32332332
      Alice Springs       11   31323332
      Gingin              12   32322432
      Canberra            11   32323331
      Kennaook Cape Grim  12   32323332
      Hobart              12   32323332    

Estimated Antarctic Regional K Indices 18 Dec :
      Macquarie Island    15   32234342
      Casey               50   56754433
      Mawson              33   54444553

Observed Regional daily pc3 Indices 18 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             6   (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 18 Dec : A 
           Fredericksburg        11
           Planetary             14                         

Observed AFr/Ap Indices 17 Dec :  A   K
           Fredericksburg        20
           Planetary             25   3544 4532     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
19 Dec     8    G0
20 Dec     5    G0
21 Dec     5    G0

COMMENT: Geomagnetic conditions on UT day 18-Dec were G0 in the 
Australian region and G0-G1 in the Antarctic region. G0 geomagnetic 
conditions are expected over 19-21 Dec.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
19 Dec      Normal-fair    Normal-fair    Fair
20 Dec      Normal         Normal         Normal-fair
21 Dec      Normal         Normal         Normal

COMMENT: HF radio propagation conditions on UT day 18-Dec were 
moderately degraded, especially in the southern hemisphere and 
in high latitudes. HF radio propagation conditions are expected 
to improve on 19-Dec and normal conditions are expected over 
20-21 Dec.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
18 Dec    63

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 30% during local day.
      Near predicted monthly values during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Depressed by 20% during local night.
   Northern Australian Region:
      Depressed by 30% during local day.
      Depressed by 25% during local night.
   Southern Australian Region:
      Depressed by 30% during local day.
      Depressed by 15% during local night.
   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
19 Dec    95    Near predicted monthly values to 10-15% depressed
20 Dec   100    Near predicted monthly values
21 Dec   110    Near predicted monthly values to 10-15% 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 18-Dec were depressed 
from 15-30%. Sporadic E was common during local night hours in 
most sites. Conditions at Darwin were significantly degraded 
during local night hours. MUFs are expected to be mildly degraded 
on 19-Dec, but on a general improving trend to near predicted 
monthly values over 20-21 Dec.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 17 Dec
       Daily Proton Fluence >1 MeV:   1.5E+07
       Daily Proton Fluence >10 MeV:  1.9E+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: C1.3

DSCOVR Satellite Solar Wind Day Averaged Data for 17 Dec
Speed: 597 km/sec  Density:    9.4 p/cc  Temp:    79800 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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