[Ips-dsgr] ASWFC Daily Report - 12 April 24 issued 2331 UT on 12 Apr 2024 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Sat Apr 13 09:31:04 EST 2024


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/12 APRIL 2024
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 12 APRIL AND FORECAST FOR 13 APRIL - 15 APRIL
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 12 Apr:  R0

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 12 Apr: 152/107


1B. SOLAR FORECAST
             13 Apr             14 Apr             15 Apr
Activity     R0-R1, chance R2   R0-R1, chance R2   R0-R1, chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   154/109            156/110            158/112

COMMENT: Solar activity on UT day 12-Apr was R0, with no significant 
solar flares. There are currently five numbered sunspots on the 
solar disk. AR3634 (N25W04, beta) and AR3633 (S10W10, alpha) 
have shown some minor growth, particularly in their trailer spots, 
but otherwise all other sunspots are either stable or in decay. 
Solar activity is expected to be R0-R1 over 13-15 Apr with a slight 
chance for R2. 

The M5 flare event that occurred from 11/1706 UT has been reassessed 
and found to be associated with a large eastern directed CME. 
This CME is not expected to be geoeffective. A small filament 
erupted near S20W20 from 12/0040 UT and was associated with a 
weak and diffuse halo CME that can be seen in SOHO difference 
imagery. This CME may arrive either late 14-Apr or else early 
15-Apr. Several small CME eruptions were observed off the eastern 
solar limb throughout the day, possibly associated with a complex 
magnetic structure behind the limb. No other noteworthy CMEs 
were observed on 12-Apr. 

S0 solar radiation storm conditions were observed on 12-Apr. S0
solar radiation storm conditions are expected over 13-15 Apr.

The solar wind environment on UT day 12-Apr was near background 
levels. The solar wind speed was steady and ranged between near 400-450 km/s.
 The peak total interplanetary field strength (IMF, Bt) was 5 nT and 
the north-south IMF component (Bz) range was +4 to -4 nT. There 
is a small coronal hole currently near S30W30 that may enhance the 
solar wind speed from 14-Apr, although this feature may be too far 
south to impact Earth. The solar wind speed may also become mildly
 enhanced on 15-Apr due to a weak CME impact. Otherwise, the solar 
wind speed is expected to be at background levels over 13-15 Apr.

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

Geomagnetic field for Australian Region 12 Apr: G0

Estimated Indices 12 Apr : A   K           
   Australian Region       3   22200001
      Cocos Island         3   22210000
      Darwin               3   22200001
      Townsville           4   22201012
      Learmonth            3   22200001
      Alice Springs        3   22200001
      Gingin               3   22200001
      Canberra             2   12100001
      Kennaook Cape Grim   2   02210001
      Hobart               3   12210011    

Estimated Antarctic Regional K Indices 12 Apr :
      Macquarie Island     1   01010011
      Casey                7   24320101
      Mawson               7   43311000

Observed Regional daily pc3 Indices 12 Apr : 
      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 12 Apr : A 
           Fredericksburg         7
           Planetary              7                         

Observed AFr/Ap Indices 11 Apr :  A   K
           Fredericksburg         6
           Planetary              4   2201 1102     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
13 Apr     6    G0
14 Apr     8    G0, chance G1
15 Apr    12    G0, chance G1

COMMENT: G0 geomagnetic conditions were observed in the Australian 
and Antarctic regions on UT day 12-Apr. G0 geomagnetic conditions 
are expected on 13-Apr. There is a chance for G1 geomagnetic 
conditions on either late 14-Apr or else early 15-Apr due to 
a possible weak CME impact.

-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
12 Apr      Normal         Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
13 Apr      Normal         Normal         Normal
14 Apr      Normal         Normal         Normal-fair
15 Apr      Normal         Normal-fair    Normal-fair

COMMENT: HF radio propagation conditions on UT day 12-Apr were 
generally normal. HF radio propagation conditions are expected 
to be mostly normal over 13-15 Apr, with the possibility of mildly 
degraded conditions at high to mid latutdes on 15-Apr due to 
a possible weak CME impact.

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


Date   T index
12 Apr   125

Observed Australian Regional MUFs
   Cocos Island Region:
      Enhanced by 20% during local day.
      Enhanced by 15% during local night.
   Niue Island Region:
      Near predicted monthly values during local day.
      Enhanced by 35% during local night.
   Northern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 15% during local night.
   Southern Australian Region:
      Mostly near predicted monthly values.
   Antarctic Region (Casey/Davis/Mawson):
      Near predicted monthly values over the UT day.

Monthly T index:
Month  T index
Mar      120
Apr      114
May      115

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
13 Apr   120    Near predicted monthly values
14 Apr   120    Near predicted monthly values
15 Apr   110    Near predicted monthly values

COMMENT: ASWFC SWF HF Communications Warning 35 was issued on 
11 April and is current for 12-14 Apr. Maximum usable frequencies 
in the Australian region on UT day 12-Apr were near predicted 
monthly values to 15% enhanced. Sporadic-E was observed in Hobart 
and Norfolk Island during local night hours. MUFs are expected 
to be near predicted monthly values over 13-15 Apr.

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

GOES satellite data for 11 Apr
       Daily Proton Fluence >1 MeV:   2.1E+05
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 7.00E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B9.3

DSCOVR Satellite Solar Wind Day Averaged Data for 11 Apr
Speed: 445 km/sec  Density:    6.1 p/cc  Temp:   166000 K  Bz:   2 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