[Ips-dsgr] ASWFC Daily Report - 29 September 23 issued 2331 UT on 29 Sep 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sat Sep 30 09:31:16 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/29 SEPTEMBER 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 29 SEPTEMBER AND FORECAST FOR 30 SEPTEMBER - 02 OCTOBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 29 Sep:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 29 Sep: 155/109


1B. SOLAR FORECAST
             30 Sep             01 Oct             02 Oct
Activity     R0-R1              R0-R1              R0-R1
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   152/107            148/102            145/99

COMMENT: Solar activity on Ut day 29-Sep was at the R0 level, 
with a few high C-class flares. The largest flare of the day 
was a C7.6, produced by an active region over the eastern limb. 
This region may produce larger flares when it rotates on to the 
solar disk. There are currently eight numbered sunspot regions 
on the solar disk. AR3449 (N15E08, beta-gamma) was the only sunspot 
region to show significant development. AR3444 (N22W61, alpha) 
showed some development but is still small and magnetically simple. 
All other sunspot regions are either stable or in decay. Solar 
activity is expected to be at R0-R1 levels over 30-Sep to 2-Oct. 
No geoeffective CMEs were observed on 29-Sep. An, on disk, filament 
eruption is visible in SDO and GOES SUVI imagery in the eastern 
hemisphere from 29/1837UT. No associated CME is visible in available 
coronagraph imagery. The solar wind speed on UT day 29-Sep increased, 
ranging from 383 km/s to 520 km/s. The solar wind speed is currently 
around 460 km/s. This elevated solar wind speed indicates that 
the coronal hole in the northern hemisphere has entered a geoeffective 
position. The total interplanetary field strength (IMF, Bt) was 
9 nT and the north-south IMF component (Bz) range was +7 to -8 
nT. A sustained period of southward Bz was observed from 29/0142UT 
to 29/1002UT. The solar wind speed is expected to remain moderate 
over 30-Sep to 1-Oct. A gradual decrease towards low speeds is 
likely on 2-Oct as the coronal hole in the northern hemisphere 
rotates away from a geoeffective position.

-----------------------------------------------------------
2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 29 Sep: G0

Estimated Indices 29 Sep : A   K           
   Australian Region       6   11242101
      Cocos Island         5   12232100
      Darwin               6   21232102
      Townsville           7   21233111
      Learmonth            8   12243101
      Alice Springs        6   11233101
      Gingin               6   11242101
      Canberra             6   01242101
      Hobart               8   12342101    

Estimated Antarctic Regional K Indices 29 Sep :
      Macquarie Island    19   02563011
      Casey               10   32243012
      Mawson              17   45442100

Observed Regional daily pc3 Indices 29 Sep : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               0   (Quiet)
      Canberra             7   (Quiet)
      Hobart              11   (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 29 Sep : A 
           Fredericksburg         9
           Planetary             13                         

Observed AFr/Ap Indices 28 Sep :  A   K
           Fredericksburg         5
           Planetary              9   1201 3332     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
30 Sep    10    G0, chance of G1
01 Oct     8    G0
02 Oct     6    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 29-Sep. Mostly G0 geomagnetic conditions were 
observed in Antarctica, with an isolated period of G1 at Mawson 
and G2 conditions at Macquarie Island. G0 geomagnetic conditions 
are expected on 30-Sep, with a chance of G1, due to ongoing coronal 
hole high speed wind stream effects. G0 conditions are expected 
over 1-2 Oct.

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

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
30 Sep      Normal         Normal         Normal-fair
01 Oct      Normal         Normal         Normal-fair
02 Oct      Normal         Normal         Normal

COMMENT: HF radio propagation conditions were mostly normal on 
29-Sep. Generally normal HF propagation conditions are expected 
over 30 Sep to 2-Oct, although some mild degradations may be 
observed over 29-Sep to 1-Oct at high latitudes due to ongoing 
coronal hole high speed wind stream effects. Isolated minor shortwave 
fadeouts are possible.

-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
29 Sep   126

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values.
   Niue Island Region:
      Enhanced by 20% during local day.
      Enhanced by 20% during local night.
      Enhanced by 20% after local dawn.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 20% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 25% during local night.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values 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
30 Sep   120    Near to 15% above predicted monthly values
01 Oct   120    Near to 15% above predicted monthly values
02 Oct   120    Near to 15% above predicted monthly values

COMMENT: Maximum usable frequencies (MUFs) in the Australian 
region on UT day 29-Sep were mostly near predicted monthly values 
to 25% enhanced. Minor spread-F was observed at Hobart during 
local night hours. MUFs are expected to be near predicted monthly 
values to 15% enhanced over 30 Sep to 2-Oct. Isolated minor shortwave 
fadeouts are possible.

-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 28 Sep
       Daily Proton Fluence >1 MeV:   2.3E+05
       Daily Proton Fluence >10 MeV:  1.8E+04
       Daily Electron Fluence >2 MeV: 5.10E+07   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 7%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.0

DSCOVR Satellite Solar Wind Day Averaged Data for 28 Sep
Speed: 398 km/sec  Density:    0.8 p/cc  Temp:    54200 K  Bz:   0 nT

(Courtesy Space Weather Prediction Center, Boulder USA)
-----------------------------------------------------------

Australian Space Weather Forecasting Centre
Bureau of Meteorology
ASWFC at bom.gov.au
www.bom.gov.au | www.sws.bom.gov.au



More information about the ips-dsgr mailing list