[Ips-dsgr] ASWFC Daily Report - 19 September 24 issued 2330 UT on 19 Sep 2024 [SEC=OFFICIAL]

Australian Space Weather Forecasting Centre aswfc at bom.gov.au
Fri Sep 20 09:30:54 AEST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/19 SEPTEMBER 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 19 SEPTEMBER AND FORECAST FOR 20 SEPTEMBER - 22 SEPTEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 19 Sep:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 19 Sep: 161/115


1B. SOLAR FORECAST
             20 Sep             21 Sep             22 Sep
Activity     R0, chance R1      R0, chance R1      R0, chance R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   160/114            155/109            150/105

COMMENT: Solar activity on UT day 19-Sep was at the R0 level, 
with several C-class flares observed. There are currently seven 
numbered sunspot regions visible on the solar disk. AR3825 (S15W12, 
gamma) is still the largest and most magnetically complex region 
on the disk but is in decay and has not produced any notable 
flares for several days. AR3827 (S28E27, beta) and AR3828 (S12E45, 
beta-delta) both showed development over the UT day, as did newly 
developed region AR3831 (N12E08, beta). All other sunspot regions 
are stable. Solar activity is expected to be at the R0 level, 
with a chance of R1 over 20-22 Sep. The >10MeV proton flux was 
close to background levels over 19-Sep. S0 conditions are expected 
over 20-22 Sep. No Earth-directed CMEs have been observed. A 
pair of slow, northwest directed CMEs were observed but both 
are considered farside events. The solar wind speed on UT day 
19-Sep was slightly in decline, ranging from 370 to 530 km/s 
and is currently near 390 km/s. The peak total interplanetary 
field strength (IMF, Bt) was 9 nT and the north-south IMF component 
(Bz) range was +7 to -9 nT. A sustained period of -Bz was observed 
from 19/1015 to 19/1740UT. The solar wind speed is expected to 
slowly decline towards background levels over 20-22 Sep as CME 
and coronal hole high speed wind stream effects wane.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 19 Sep: G1

Estimated Indices 19 Sep : A   K           
   Australian Region      11   22233421
      Cocos Island         8   22232320
      Darwin              10   22133421
      Townsville          12   22134422
      Learmonth           14   22233531
      Alice Springs       13   22133521
      Gingin              16   32234521
      Canberra            10   22133421
      Kennaook Cape Grim  12   22234421
      Hobart              12   22234421    

Estimated Antarctic Regional K Indices 19 Sep :
      Macquarie Island    22   23245541
      Casey               22   54433333
      Mawson              34   54443562

Observed Regional daily pc3 Indices 19 Sep : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             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 19 Sep : A 
           Fredericksburg        15
           Planetary             21                         

Observed AFr/Ap Indices 18 Sep :  A   K
           Fredericksburg        10
           Planetary              9   4211 2223     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
20 Sep    10    G0, chance of G1
21 Sep     8    G0
22 Sep     5    G0

COMMENT: Mostly G0 geomagnetic conditions were observed in the 
Australian region on UT day 19-Sep with a period of G1 conditions 
observed at Learmonth, Alice Springs and Gingin. Mostly G1 conditions 
were observed in the Antarctic region, with a period of G2 at 
Mawson. G0 geomagnetic conditions, with a chance of G1 are expected 
on 20-Sep as CME and coronal hole high speed wind stream effects 
wane. G0 geomagnetic conditions are expected over 21-22 Sep.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
19 Sep      Normal-fair    Normal-fair    Fair-poor      

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
20 Sep      Normal         Normal         Normal-fair
21 Sep      Normal         Normal         Normal-fair
22 Sep      Normal         Normal         Normal

COMMENT: HF radio communication conditions on UT day 19-Sep improved 
over the course of the day, poor to fair conditions were observed 
at high latitudes and fair to normal conditions were observed 
at mid and low latitudes. Mostly normal HF conditions are expected 
over 20-22 Sep.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
19 Sep   152

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 15% during local day.
      Enhanced by 40% during local night.
   Niue Island Region:
      Enhanced by 50% during local day.
      Enhanced by 45% during local night.
   Northern Australian Region:
      Enhanced by 20% during local day.
      Enhanced by 40% during local night.
   Southern Australian Region:
      Near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Aug      159
Sep      117
Oct      116

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
20 Sep   160    Near to 15% above predicted monthly values
21 Sep   160    Near to 15% above predicted monthly values
22 Sep   160    Near to 15% above predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the northern Australian 
region on UT day 19-Sep were generally near predicted monthly 
values to 20-40% enhanced, with the strongest enhancements observed 
during local night. MUFs in the southern Australian region were 
near predicted monthly values. Spread F was observed at Hobart 
during local night hours. MUFs are expected to be near predicted 
monthly values to 15% enhanced over 20-22 Sep.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 18 Sep
       Daily Proton Fluence >1 MeV:   5.4E+07
       Daily Proton Fluence >10 MeV:  1.6E+05
       Daily Electron Fluence >2 MeV: 9.00E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 2%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.0

DSCOVR Satellite Solar Wind Day Averaged Data for 18 Sep
Speed: 439 km/sec  Density:    0.3 p/cc  Temp:    96200 K  Bz:   0 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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