[Ips-dsgr] ASWFC Daily Report - 14 September 23 issued 2330 UT on 14 Sep 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Fri Sep 15 09:30:40 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/14 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 14 SEPTEMBER AND FORECAST FOR 15 SEPTEMBER - 17 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 14 Sep:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.4    0745UT  possible   lower  Mid East/Indian
  M1.9    1931UT  possible   lower  East Pacific/
                                    North American
  M2.5    2126UT  possible   lower  East Pacific/
                                    North American

Observed 10.7 cm flux/Equivalent Sunspot Number for 14 Sep: 145/99


1B. SOLAR FORECAST
             15 Sep             16 Sep             17 Sep
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   145/99             148/102            145/99

COMMENT: Solar activity on UT day 14-Sep was at the R1 level, 
with an M1.4 flare at 14/0745UT, an M1.9 flare at 14/1931UT and 
an M2.5 flare at 14/2126UT. 

There are currently six numbered sunspot regions visible on the 
solar disk and one unnumbered region. AR3429 (N11E06, beta) was 
responsible for the M1.9 and M2.5 flares and was partially 
responsible for the long duration M1.4 flare. This region displayed 
spot development over the UT day and is rotating towards a prime 
geoeffective location. The largest component of the long duration 
M1.4 flare was produced between AR3423 (N17W75, beta) and AR3425 
(N25W38, beta), both of these regions displayed spot decay over 
the UT day. All other sunspot regions are either stable or in decay. 
An unnumbered region is visible at S12E04 with beta magnetic 
characteristics. 

Solar activity is expected to be at R0-R1 levels, over 15-17 Sep. 

The long duration M1.4 flare at 14/0745UT produced a slight 
enhancement in the >10MeV proton flux, however S0 conditions 
are expected over 15-Sep. 

The long duration M1.4 flare at 14/0745UT is associated with a 
partial halo CME visible in SOHO and STEREO-A imagery from 14/0724UT. 
This CME consists of a dense bulk which is directed to the west 
and a, much fainter and slower, partial halo component. Modelling 
indicates that a glancing impact from the main bulk is expected on 
16-Sep at 2100UT +/- 12 hours and a direct impact from the fainter 
halo is expected on 17-Sep at 1000UT +/- 12 hours. No other 
geoeffective CMEs were observed on 15-Sep. 
A filament liftoff centered at around N45W10 is visible 
in SDO, GOES SUVI and H-Alpha imagery from 14/2018UT. No associated 
CME is visible in available imagery, further analysis will be 
performed when more imagery becomes available. 

The solar wind speed increased on 13-Sep, ranging from 353 to 
526 km/s and is currently near 480 km/s. The peak total 
interplanetary field strength (IMF, Bt) was 11 nT and the north-south 
IMF component (Bz) range was +9 to -10 nT. A sustained period of 
-Bz was observed from 14/1629UT to 14/1820UT. 

The solar wind speed is expected to remain moderately elevated over 
15-16 Sep with the chance of a gradual decline. An enhancement in 
solar wind speed is expected late on 16-Sep due to a glancing impact 
from a CME first observed on 14-Sep. A further enhancement is 
expected on 17-Sep due to an impact from a CME first observed on 14-Sep.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 14 Sep: G0

Estimated Indices 14 Sep : A   K           
   Australian Region       9   22321133
      Cocos Island        10   22311134
      Darwin               8   22221133
      Townsville           8   23222132
      Learmonth            -   --------
      Alice Springs       10   23321133
      Gingin              15   32311245
      Canberra             9   22321133
      Hobart              10   22321134    

Estimated Antarctic Regional K Indices 14 Sep :
      Macquarie Island    15   33320253
      Casey               25   35521254
      Mawson              46   64422267

Observed Regional daily pc3 Indices 14 Sep : 
      Darwin               0   (Quiet)
      Townsville           2   (Quiet)
      Learmonth           NA
      Alice Springs        2   (Quiet)
      Gingin              22   (Quiet to unsettled)
      Canberra            36   (Quiet to unsettled)
      Hobart              31   (Quiet to unsettled)

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 14 Sep : A 
           Fredericksburg        12
           Planetary             13                         

Observed AFr/Ap Indices 13 Sep :  A   K
           Fredericksburg        17
           Planetary             18   5443 3323     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
15 Sep    10    G0, chance of G1
16 Sep    20    G1, chance of G2
17 Sep    25    G1-G2

COMMENT: Mostly G0 geomagnetic conditions were observed in the 
Australian region on 14-Sep, with a period of G1 observed at 
Gingin. G1 conditions were mostly observed in the Antarctic region 
with periods of G2-G3 observed at Mawson. G0 geomagnetic conditions, 
with a chance of G1, are expected on 15-Sep due to ongoing geomagnetic 
activity. G1 conditions, with a chance of G2 are expected on 
16-Sep due to an anticipated glancing impact late in the UT day, 
from a CME first observed on 14-Sep. G1-G2 conditions are expected 
on 17-Sep due to an impact from a CME first observed on 14-Sep, 
combined with geomagnetic activity from the glancing impact on 
16-Sep.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
14 Sep      Fair-normal    Fair-normal    Poor-fair      

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
15 Sep      Normal         Normal         Normal-fair
16 Sep      Normal         Normal-fair    Fair
17 Sep      Fair           Fair           Fair-poor

COMMENT: HF radio propagation conditions on UT day 14-Sep were 
degraded at middle to high latitudes for the first part of the 
UT day and mostly normal for the rest of the day. Mostly normal 
HF conditions are expected on 15-16 Sep, with degraded conditions 
possible late on 16-Sep, especially at high latitudes, due to 
anticipated geomagnetic activity. Degraded conditions are expected 
on 17-Sep, especially at high latitudes, due to anticipated geomagnetic 
activity. Isolated shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
14 Sep    95

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 55% during local day.
      Enhanced by 45% during local night.
   Northern Australian Region:
      Near predicted monthly values.
   Southern Australian Region:
      Depressed by 15% during local day.
      Near predicted monthly values during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Depressed 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
15 Sep   100    Near predicted monthly values
16 Sep   110    Near predicted monthly values
17 Sep    90    Depressed 10 to 15%/near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 91 was issued on 
14 September and is current for 14-16 Sep. Maximum usable frequencies 
(MUFs) on UT day 14-Sep were depressed by up to 15% in the southern 
Australian region and near predicted monthly values in the northern 
Australian region. Significant spread F was observed at Brisbane, 
Canberra, Perth and Hobart. MUFs are generally expected to be 
near predicted monthly values on 15-16 Sep, with mild depressions 
possible late on 16-Sep due to anticipated geomagnetic activity. 
Depressions of up to 15% are expected on 17-Sep due to anticipated 
geomagnetic activity. Depressions are expected to be more prevalent 
in the southern Australian region. Isolated shortwave fadeouts 
are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 13 Sep
       Daily Proton Fluence >1 MeV:   4.5E+05
       Daily Proton Fluence >10 MeV:  2.0E+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: B7.8

DSCOVR Satellite Solar Wind Day Averaged Data for 13 Sep
Speed: 426 km/sec  Density:    5.9 p/cc  Temp:   106000 K  Bz:  -3 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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