[Ips-dsgr] ASWFC Daily Report - 17 November 23 issued 2331 UT on 17 Nov 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sat Nov 18 10:31:01 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 NOVEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 17 NOVEMBER AND FORECAST FOR 18 NOVEMBER - 20 NOVEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 17 Nov:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Nov: 120/72


1B. SOLAR FORECAST
             18 Nov             19 Nov             20 Nov
Activity     R0, chance R1      R0, chance R1      R0, chance R1
Fadeouts     None expected      None expected      Possible
10.7cm/SSN   120/72             120/72             120/72

COMMENT: Solar activity on UT day 17-Nov was R0, with no significant 
solar flares or radio blackouts. There are currently four numbered 
active regions on the solar disk, although only two of these 
have any sunspots. AR3486 (S08W70, beta) has been stable, but 
is soon to rotate over the western solar limb and out of view. 
AR3489 (S15E77, beta) is just rotating into view on the eastern 
solar limb, but has so far been mostly stable. AR3489 is currently 
the only noteworthy sunspot region. Solar activity is expected 
to be mostly R0 over 18-20 Nov, although low level R1 flares 
may be possible from AR3489. 

Several CMEs were observed on 17-Nov, but none are considered 
geoeffective. Most CMEs that were observed were due to
 prominence eruptions or else on the farside of the 
Sun, and most were either very narrow or very slow. There is 
an unstable filament near S10E22, and while it has not yet erupted 
it will be monitored closely. 

The solar wind parameters on UT day 17-Nov were generally 
indicative of background conditions. The solar wind speed 
was on a slight declining trend and ranged between 388 to 294 km/s. 
The peak total interplanetary field strength (IMF, Bt) was 4 nT 
and the north-south IMF component (Bz) range was +3 to -3 nT. 
The solar wind speed is expected to remain near background 
levels on 18-Nov. An increase to the solar wind
 parameters is expected on either late 19-Nov or early 20-Nov due
to the arrival of a weak partial halo CME that was first seen on 16-Nov. 
There are several very small and faint coronal holes over the 
solar disk that may also cause some mild increases to the solar 
wind speed over 18-20 Nov, although it is not likely to be significant.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 17 Nov: G0

Estimated Indices 17 Nov : A   K           
   Australian Region       2   10000211
      Cocos Island         2   20000210
      Darwin               1   10000111
      Townsville           1   00000111
      Learmonth            1   00000211
      Alice Springs        1   00000201
      Gingin               2   10000300
      Canberra             0   00100100
      Hobart               2   01110210    

Estimated Antarctic Regional K Indices 17 Nov :
      Macquarie Island     0   00010000
      Casey                8   33321211
      Mawson              11   22212442

Observed Regional daily pc3 Indices 17 Nov : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               0   (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 17 Nov : A 
           Fredericksburg         3
           Planetary              4                         

Observed AFr/Ap Indices 16 Nov :  A   K
           Fredericksburg         7
           Planetary              7   1022 2222     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
18 Nov    10    G0
19 Nov    20    G0, chance G1
20 Nov    20    G1, slight chance G2

COMMENT: ASWFC Geomagnetic Warning 69 was issued on 16 November 
and is current for 19-20 Nov. G0 geomagnetic conditions were 
observed in the Australian and Antarctica regions on UT day 17-Nov. 
G0 geomagnetic conditions are mostly expected over 18-19 Nov. 
G1 geomagnetic conditions are expected either late on 19-Nov 
or on early UT day 20-Nov due to the anticipated arrival of a 
weak partial halo CME that was first seen on 16-Nov, with a slight 
chance of isolated G2.

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

PCA Event : No event.

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

COMMENT: HF radio communication conditions were generally normal 
on 17-Nov, although sporadic-E may have degraded conditions for 
low latitude regions. Generally normal HF communication conditions 
are expected over 18-19 Nov, with some mild degradations during 
local night hours. Stronger degradations are expected by 20-Nov 
due to anticipated geomagnetic activity.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
17 Nov    95

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Mostly near predicted monthly values.
   Northern Australian Region:
      Mostly near predicted monthly values.
      Depressed by 20% after local dawn.
   Southern Australian Region:
      Depressed by 20% 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
Oct      130
Nov      100
Dec      98

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
18 Nov    95    Near predicted monthly values to 15% depressed
19 Nov    90    Near predicted monthly values to 15% depressed
20 Nov    80    Near predicted monthly values to 20-30% depressed.

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region were mostly near predicted values, although there were 
depressions observed after local dawn hours and also during daylight 
hours for the southern Australian region. The reason behind 
the depressions may be due to the lack of sunspots on the visible 
disk at the moment, but this is not expected to continue significantly. 
Sporadic-E was observed at Brisbane, Cocos Islands and Norfolk 
Island during local night hours, with Brisbane being heavily affected. 
MUFs are expected to be near predicted values to 15% depressed 
over 18-20 Nov during local dawn hours. Further depressions up 
to 20-30% are possible from 20-Nov due to expected geomagnetic 
activity.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 16 Nov
       Daily Proton Fluence >1 MeV:   4.4E+04
       Daily Proton Fluence >10 MeV:  1.7E+04
       Daily Electron Fluence >2 MeV: 7.20E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B8.6

DSCOVR Satellite Solar Wind Day Averaged Data for 16 Nov
Speed: 422 km/sec  Density:    4.1 p/cc  Temp:   106000 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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