[Ips-dsgr] ASWFC Daily Report - 27 October 23 issued 2330 UT on 27 Oct 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sat Oct 28 10:30:11 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/27 OCTOBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 27 OCTOBER AND FORECAST FOR 28 OCTOBER - 30 OCTOBER
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 27 Oct:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M1.4 26/2324UT  possible   lower  West Pacific

Observed 10.7 cm flux/Equivalent Sunspot Number for 27 Oct: 128/81


1B. SOLAR FORECAST
             28 Oct             29 Oct             30 Oct
Activity     R0, chance of R1   R0, chance of R1   R0, chance of R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   128/81             130/84             130/84

COMMENT: Solar activity on UT day 27-Oct was at the R1 level, 
due to the tail of a long duration M1 flare at 26/2315UT. There 
are currently five numbered sunspot regions on the solar disk. 
AR3273 (N13E54, beta) was responsible for the M1 flare on 26-Oct. 
This area is small and near the eastern limb, making the magnetic 
character difficult to determine, there is a possible delta spot 
present in this active region. AR3472 (N20E30, beta) showed spot 
development over the UT day, with one pair of spots decaying 
to be replaced by another two prominent spots. All other active 
regions were either stable or in decay. Overall, the sunspot 
regions on the disk are not currently significantly complex and 
solar activity over 28-30 Oct is expected to be R0 with a chance 
of R1. A fast, partial halo, east-directed CME, resulting from 
the M1 flare on 26-Oct is visible in SOHO and STEREO-A imagery 
from 26/2314UT. Modelling suggests a chance of a glancing impact 
on the first half of 29-Oct, however the vast majority of the 
material will pass behind the Earth. No other geoeffective CMEs 
were observed on 27-Oct. The solar wind speed on UT day 27-Oct 
decreased, ranging between 500 and 345 km/s and is currently 
near 345 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 11 nT and the north-south IMF component (Bz) range was 
+4 to -9 nT. The solar wind speed is expected to continue to 
decrease towards background levels over 28-Oct. There is a chance 
of an increase in the first half of 29-Oct due to a possible 
glancing impact from the CME discussed above. A further increase 
is expected on 30-Oct due to high speed wind stream effects from 
a large equatorial coronal hole currently approaching a geoeffective 
location.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 27 Oct: G0

Estimated Indices 27 Oct : A   K           
   Australian Region       6   22222121
      Cocos Island         4   22211111
      Darwin               6   22222122
      Townsville           8   33222122
      Learmonth            7   32222221
      Alice Springs        5   22222111
      Gingin               7   32222221
      Canberra             5   22222111
      Hobart               7   23223111    

Estimated Antarctic Regional K Indices 27 Oct :
      Macquarie Island    13   33443111
      Casey               15   45331122
      Mawson              26   45533343

Observed Regional daily pc3 Indices 27 Oct : 
      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 27 Oct : A 
           Fredericksburg        14
           Planetary             16                         

Observed AFr/Ap Indices 26 Oct :  A   K
           Fredericksburg        18
           Planetary             23   2214 5454     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
28 Oct     8    G0
29 Oct    12    G0, chance of G1
30 Oct    16    G0, chance of G1

COMMENT: G0 geomagnetic conditions were observed in the Australia 
region on UT day 27-Oct. G1 conditions were observed at Casey 
and Mawson, whilst G0 conditions were observed at Macquarie Island. 
G0 conditions are expected over 28-30 Oct, with a chance of G1 
on 29-30 Oct due to a possible glancing impact from a CME on 
29-Oct and high speed wind stream effects from an equatorial 
coronal hole currently approaching a geoeffective position on 
30-Oct.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
27 Oct      Normal         Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
28 Oct      Normal         Normal         Normal-fair
29 Oct      Normal         Normal         Normal-fair
30 Oct      Normal         Normal         Normal-fair

COMMENT: HF radio propagation conditions were mostly normal on 
27-Oct. Mostly normal conditions are expected over 28-30 Oct, 
with the chance of minor degradations at high latitudes on 29-30 
Oct due to possible geomagnetic activity.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
27 Oct   118

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 15% during local day.
      Near predicted monthly values during local night.
   Northern Australian Region:
      Mostly near predicted monthly values.
   Southern Australian Region:
      Enhanced by 15% 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
Sep      104
Oct      98
Nov      96

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
28 Oct   120    Near to 15% above predicted monthly values
29 Oct   120    Near to 15% above predicted monthly values
30 Oct   120    Near to 15% above predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 105 was issued on 
26 October and is current for 27-28 Oct. Maximum usable frequencies 
(MUFs) in the Australian region on UT day 27-Oct were near predicted 
monthly values, with enhancements of up to 15% during local day 
in the southern Australian region and mild depressions at Learmonth 
and Perth during local day. MUFs are expected to be near predicted 
monthly values to 15% enhanced over 28-30 Oct.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 26 Oct
       Daily Proton Fluence >1 MeV:   5.6E+04
       Daily Proton Fluence >10 MeV:  1.8E+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: B5.9

DSCOVR Satellite Solar Wind Day Averaged Data for 26 Oct
Speed: 398 km/sec  Density:    6.7 p/cc  Temp:    83600 K  Bz:  -1 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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