[Ips-dsgr] ASWFC Daily Report - 21 July 23 issued 2330 UT on 21 Jul 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sat Jul 22 09:30:52 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 JULY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 21 JULY AND FORECAST FOR 22 JULY - 24 JULY
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 21 Jul:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Jul: 173/127


1B. SOLAR FORECAST
             22 Jul             23 Jul             24 Jul
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   170/124            170/124            165/119

COMMENT: Solar activity on UT day 21-Jul was at the R0 level, 
with no large C-class flares. There are currently six numbered 
sunspot regions visible on the solar disk. AR3373 (N08W25, beta-delta) 
is the largest and most magnetically complex region on the solar 
disk and exhibited movement in its trailer spots over the UT 
day. All other sunspot regions are either stable or in decay. 
Solar activity is expected to be at R0-R1 levels over 22-24 Jul. 
The >10MeV proton flux was elevated over 21-Jul but below S0 
conditions. The >10MeV proton flux is expected to continue to 
decline to background levels and S0 conditions are expected over 
22-24 Jul. No geoeffective CMEs were observed on 21-Jul. A weak 
shock in solar wind speed and IMF conditions was observed at 
21/1927UT, likely due to the anticipated impact from a CME first 
observed on 18-Jul. The solar wind speed on UT day 21-Jul increased 
after the weak shock, ranging from 366 to 448 km/s, and is currently 
near 430 km/s. The peak total interplanetary field strength (IMF, 
Bt) was 15 nT and the north-south IMF component (Bz) range was 
+9 to -15 nT. A sustained period of -Bz began at 21/2046UT and 
is ongoing. The solar wind speed is expected to continue to increase 
over the first half of 22-Jul following the weak shock observed 
at 21/1927UT. The solar wind speed is expected to decline to 
background levels over 23-24 Jul.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 21 Jul: G0

Estimated Indices 21 Jul : A   K           
   Australian Region       5   23210112
      Cocos Island         4   22200112
      Darwin               6   23211112
      Townsville           7   23211123
      Alice Springs        5   23210112
      Gingin               7   23310122
      Canberra             5   23210012
      Hobart               4   12211022    

Estimated Antarctic Regional K Indices 21 Jul :
      Macquarie Island     4   11221111
      Casey                9   33321212
      Mawson              14   44311224

Observed Regional daily pc3 Indices 21 Jul : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth           NA
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart               8   (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 21 Jul : A 
           Fredericksburg        11
           Planetary             14                         

Observed AFr/Ap Indices 20 Jul :  A   K
           Fredericksburg        10
           Planetary             11   1101 1444     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
22 Jul    12    G0, chance of G1
23 Jul     8    G0
24 Jul     5    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 21-Jul. G0 geomagnetic conditions 
are expected on 22-Jul, with a chance of G1 due to ongoing effects 
from a recently observed CME impact. G0 conditions are expected 
over 23-24 Jul.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
21 Jul      Normal         Normal         Normal         

PCA Event : 10MeV Proton/PCA Event Began at 0105UT 18/07, Ended at 0335UT 20/07

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
22 Jul      Normal         Normal         Normal-fair
23 Jul      Normal         Normal         Normal-fair
24 Jul      Normal         Normal         Normal

COMMENT: HF communication conditions on UT day 21-Jul were mostly 
normal. Mostly normal HF conditions are expected on 22-Jul, with 
a slight chance of mild degradations at high latitudes in the 
second half of the UT day, due to geomagnetic activity from a 
recently observed CME impact. Mostly normal HF conditions are 
expected over 23-24 Jul. Isolated shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
21 Jul   116

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 25% during local day.
      Near predicted monthly values during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 30% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Enhanced by 20% during local day.
      Enhanced by 25% during local night.
      Enhanced by 20% after local dawn.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Jun      98
Jul      91
Aug      88

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
22 Jul   110    Near predicted monthly values, with a chance 
                of mild depressions.
23 Jul   115    Near to 15% above predicted monthly values
24 Jul   110    Near to 15% above predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) on UT day 21-Jul were 
generally near predicted monthly values to 25% enhanced in the 
southern Australian region and near predicted monthly values 
to 15% enhanced in the northern Australian region. MUFs are expected 
to be generally near predicted monthly values on 22-Jul, with 
a chance of mild depressions in the southern Australian region, 
due to geomagnetic activity from a recently observed CME impact. 
MUFs are expected to be near predicted monthly values to 15% 
enhanced over 23-24 Jul. Isolated shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 20 Jul
       Daily Proton Fluence >1 MeV:   3.6E+07
       Daily Proton Fluence >10 MeV:  5.5E+05
       Daily Electron Fluence >2 MeV: 5.60E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 7%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.1

DSCOVR Satellite Solar Wind Day Averaged Data for 20 Jul
Speed: 395 km/sec  Density:    3.8 p/cc  Temp:    73600 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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