[Ips-dsgr] ASWFC Daily Report - 11 September 23 issued 2330 UT on 11 Sep 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Tue Sep 12 09:30:08 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/11 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 11 SEPTEMBER AND FORECAST FOR 12 SEPTEMBER - 14 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 11 Sep:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.3    0128UT  possible   lower  West Pacific
  M1.1    0407UT  possible   lower  E. Asia/Aust.
  M1.1    1449UT  possible   lower  South American/
                                    Atlantic

Observed 10.7 cm flux/Equivalent Sunspot Number for 11 Sep: 176/130


1B. SOLAR FORECAST
             12 Sep             13 Sep             14 Sep
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   175/129            170/124            168/122

COMMENT: Solar activity on UT day 11-Sep was at the R1 level, 
with three M1 class flares. Solar region AR3429(N11E49, beta) 
produced an M1.3 flare at 11/0128UT which had a duration of 49 
minutes. Solar region AR3431(S08E51, beta) produced two M1.1 
flares at 11/0407UT and 11/1449 UT and four C class flares. Solar 
region AR3425(N27E05, beta) produced a C5 flare and AR3423(N17W32, 
beta) produced a C7 flare. Solar region AR3423 is currently the 
largest region on the disk and has been stable. Region AR3425 
is showing growth in its trailer spots and region AR3429 has 
developed an intermediate spot. Solar region AR3431 is showing 
spot redistribution. Solar region AR3430(S16W02, beta) is growing 
and has remained flare quiet. There are currently ten numbered 
sunspot regions visible on the solar disk. A new region is rotating 
onto the solar disk at solar latitude N28. All other sunspot 
regions are either stable or in decay. Solar activity is expected 
to be at R0-R1 levels over 12-14 Sep. The relatively long duration 
M1.3 flare had an associated north east non Earth directed 
CME observed from 11/0148UT. Event modelling shows an Earth miss. 
A semi halo south directed CME was observed from 11/1100UT and 
has been associated with an erupting prominence near the south 
east polar limb visible in GOES SUVI 304 from 11/1025UT. This CME 
is considered non Earth directed. A small solar filament then 
erupted (GONG H-alpha imagery) at 11/1410UT centred at S22W05. 
A narrower more minor slower CME appears associated with this 
on disk solar filament eruption which was observed from 11/1436UT 
directed to the south and east. This CME was difficult to discern 
due to the earlier larger south polar prominence CME. Preliminary 
analysis shows a very slow CME with no significant impact to the Earth's 
magnetosphere. The solar wind speed on UT day 11-Sep slowly increased, 
ranging from 351 to 429 km/s and is currently near 400 km/s. 
The peak total interplanetary field strength (IMF, Bt) was 8 
nT and the north-south IMF component (Bz) range was +7 to -6 
nT. The mild increase in wind speed is due to a coronal hole 
wind stream. The solar wind speed is expected to be mildly elevated 
today. Two small coronal holes near the solar central meridian 
may mildly increase the solar wind speed in 3-4 days time.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 11 Sep: G0

Estimated Indices 11 Sep : A   K           
   Australian Region       5   22112112
      Cocos Island         4   22211011
      Darwin               4   22111102
      Townsville           5   22112122
      Learmonth            6   22212212
      Alice Springs        4   22111102
      Gingin               4   21111112
      Canberra             3   11112111
      Hobart               4   11112211    

Estimated Antarctic Regional K Indices 11 Sep :
      Macquarie Island     1   11011100
      Casey                -   --------
      Mawson              10   23112234

Observed Regional daily pc3 Indices 11 Sep : 
      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 11 Sep : A 
           Fredericksburg         7
           Planetary              7                         

Observed AFr/Ap Indices 10 Sep :  A   K
           Fredericksburg         6
           Planetary              3   1001 1111     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
12 Sep    10    G0
13 Sep    10    G0
14 Sep     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 11-Sep. G0 geomagnetic conditions 
are expected over 12-14 Sep. A coronal hole wind stream my very 
mildly increase geomagnetic activity 12-13 Sep.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
12 Sep      Normal         Normal         Normal-fair
13 Sep      Normal         Normal         Normal-fair
14 Sep      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions on UT day 11-Sep were 
normal. Mostly normal HF conditions are expected over 12-14 Sep. 
Isolated minor shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
11 Sep   105

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Niue Island Region:
      Mostly near predicted monthly values.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Enhanced by 20% over the UT day.

Monthly T index:
Month  T index
Aug      115
Sep      96
Oct      93

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
12 Sep   110    Near predicted monthly values
13 Sep   110    Near predicted monthly values
14 Sep   110    Near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 89 was issued on 
11 September and is current for 11-13 Sep. Maximum usable frequencies 
(MUFs) on UT day 11-Sep were near predicted monthly values to 
20% enhanced in the Australian region. Spread F was observed 
at Hobart during local night hours. Ionospheric scintillation 
was observed at Niue 11/0717-0740UT. Very minor fadeouts may 
have been experienced at 11/0128UT and 11/0407UT in association 
with M1 flare activity. MUFs are expected to be near predicted 
monthly values over 12-14 Sep. Isolated minor shortwave fadeouts 
are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 10 Sep
       Daily Proton Fluence >1 MeV:   2.3E+05
       Daily Proton Fluence >10 MeV:  2.0E+04
       Daily Electron Fluence >2 MeV: 2.40E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.1

DSCOVR Satellite Solar Wind Day Averaged Data for 10 Sep
Speed: 343 km/sec  Density:    2.5 p/cc  Temp:    60300 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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