[Ips-dsgr] SWS Daily Report - 21 December 21 issued 2333 UT on 21 Dec 2021

rwc rwc at ips.gov.au
Wed Dec 22 10:33:33 EST 2021


SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/21 DECEMBER 2021 BY Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 21 DECEMBER AND FORECAST FOR 22 DECEMBER - 24 DECEMBER
STATUS INDICATORS SOL:** YELLOW **   MAG:GREEN     ION: GREEN
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1A. SOLAR SUMMARY
Activity 21 Dec:  Moderate

Flares    Max     Fadeout    Freq.  Sectors
  M1.1    0750UT  possible   lower  Mid East/Indian
  M1.4    1144UT  possible   lower  European

Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Dec: 137/91


1B. SOLAR FORECAST
             22 Dec             23 Dec             24 Dec
Activity     Low to moderate    Low to moderate    Low to moderate
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   136/90             134/88             134/88

COMMENT: Solar activity was moderate for UT day 21 December, 
with two M-class flares and multiple C-class flares. The M-class 
flares were from Region 2961, which is currently located near 
the East limb (S16E80) and rotating towards the solar centre. 
There are currently 12 numbered regions on the visible solar 
disk. Solar activity is expected to be low to moderate over the 
next 3 days, with a chance of isolated M-class flares. During 
the last 24-hours, two CMEs were observed. The first CME was 
observed erupting at 21/1745 UT from near S30E40 and is not likely 
to impact the Earth. The second CME eruption start at 21/1900 
from S10W05, is currently being modelled. Based on the location 
of the second CME, it is likely to impact the Earth. The solar 
wind speed during the last 24 hours was at moderately elevated 
level and ranged from 570 to 630 km/s, in response to the coronal 
hole effects. The peak total IMF (Bt) was mostly steady near 
5 nT and the north-south IMF (Bz) range was +5/-5 nT. The two 
day outlook (UT day 22 and 23 December) is for solar wind speed 
to decline gradually, though remain elevated, as the coronal 
hole effect wanes. From late UT day 23 December, the solar wind 
may enhance again due to the anticipated arrival of the 20 December 
CME.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 21 Dec: Quiet to Unsettled

Estimated Indices 21 Dec : A   K           
   Australian Region       7   31213121
      Cocos Island         6   31212220
      Darwin               5   21212121
      Townsville           6   32212121
      Learmonth            8   32213131
      Alice Springs        6   21213121
      Gingin               7   31213121
      Canberra             6   21213121
      Hobart               7   31213121    

Estimated Antarctic Regional K Indices 21 Dec :
      Macquarie Island     8   32204120
      Casey               26   54633232
      Mawson              22   44334352

Observed Regional daily pc3 Indices 21 Dec : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin              14   (Quiet)
      Canberra            12   (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 Dec : A 
           Fredericksburg         9
           Planetary             11                         

Observed AFr/Ap Indices 20 Dec :  A   K
           Fredericksburg        13
           Planetary             11   3323 2312     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
22 Dec     8    Quiet to Unsettled
23 Dec    10    Quiet to Unsettled
24 Dec    15    Unsettled to Active

COMMENT: SWS Geomagnetic Warning 42 was issued on 20 December 
and is current for 20-22 Dec. Quiet to unsettled geomagnetic 
conditions were observed for the Australian region on UT day 
21 December. Unsettled to a isolated storm period for Antarctic 
regions. These disturbed conditions were in response to the moderately 
elevated solar wind speed associated with the coronal hole effect. 
Geomagnetic conditions are expected to be quiet to unsettled 
with possible isolated active periods for 22 and 23 December. 
The glancing blow from the 20 December CME associated with the 
M-class flare is expected to cause some active periods from late 
UT day 23 December.

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

PCA Event : No event.

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

COMMENT: Mostly normal HF conditions are expected during 22-24 
December with shortwave fadeouts possible on daylight HF circuits.

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


Date   T index
21 Dec    61

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

Monthly T index:
Month  T index
Nov      3
Dec      33
Jan      36

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
22 Dec    50    Near to 15% above predicted monthly values
23 Dec    50    Near to 15% above predicted monthly values
24 Dec    50    Near to 15% above predicted monthly values

COMMENT: SWS HF Communications Warning 41 was issued on 20 December 
and is current for 20-22 Dec. MUFs in the Australian region for 
21 December ranged from near predicted monthly values to slightly 
enhanced by 20% for Equatorial and Northern AUS regions. MUFs 
are expected to be mostly near predicted monthly values to slightly 
enhanced levels to due above average levels of solar ionising 
flux. Shortwave fadeouts possible on daylight HF circuits.

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

GOES satellite data for 20 Dec
       Daily Proton Fluence >1 MeV:   2.0E+05
       Daily Proton Fluence >10 MeV:  4.4E+04
       Daily Electron Fluence >2 MeV: 1.80E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: B6.8

DSCOVR Satellite Solar Wind Day Averaged Data for 20 Dec
Speed: 546 km/sec  Density:   10.9 p/cc  Temp:   378000 K  Bz:   1 nT

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

Space Weather Services              email: asfc at bom.gov.au
Bureau of Meteorology
PO Box 1386                         WWW: http://www.sws.bom.gov.au
Haymarket NSW 1240  AUSTRALIA       FTP: ftp://ftp-out.sws.bom.gov.au
tel: +61 2 9213 8010                fax: +61 2 9213 8060 

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