[Ips-dsgr] ASWFC Daily Report - 20 February 23 issued 2331 UT on 20 Feb 2023 [SEC=OFFICIAL]

Regional Warning Centre rwc at ips.gov.au
Tue Feb 21 10:31:16 EST 2023


SUBJ: ASWFC DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/20 FEBRUARY 2023
FROM THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE
SUMMARY FOR 20 FEBRUARY AND FORECAST FOR 21 FEBRUARY - 23 FEBRUARY
STATUS INDICATORS SOL:** YELLOW **   MAG:** YELLOW **     ION: GREEN
ASWAS SCALE DESCRIPTION: https://bit.ly/3lmaMBx
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1A. SOLAR SUMMARY
Activity 20 Feb:  R1

Flares    Max     Fadeout    Freq.  Sectors
  M4.4    1458UT  possible   lower  South American/
                                    Atlantic

Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Feb: 160/114


1B. SOLAR FORECAST
             21 Feb             22 Feb             23 Feb
Activity     R1, chance R2      R1, chance R2      R1, chance R2
Fadeouts     Possible           Possible           Possible
10.7cm/SSN   158/112            156/110            152/107

COMMENT: Solar activity on UT day 20-Feb was at the R1 level 
due to a M4.4 flare from an unnumbered active region in the northeast 
quadrant at 20/1458UT. There are currently six numbered sunspot 
regions visible on the solar disk and two unnumbered regions. 
AR3217 (S12W84, alpha) is stable and will soon rotate over the 
western limb. AR3229 (N26E19, beta) produced only low level C-class 
flares and decayed over the UT day. An unnumbered region recently 
appeared at N17E09 (alpha) and has since decayed. A second unnumbered 
region recently rotated over the eastern limb at N26E85 (beta), 
producing the aforementioned R1 flare and appears stable. All 
other sunspot regions are either stable or in decay. Solar activity 
is expected to be at the R1 level over 21-23 Feb, with a chance 
of R2. Several CMEs were observed, but none are considered geoeffective. 
The solar wind speed on UT day 20-Feb increased, ranging from 
325 to 490 km/s, and is currently near 420 km/s. The peak total 
interplanetary field strength (IMF, Bt) was 16 nT, and the north-south 
IMF component (Bz) range was +10 to -7 nT. The solar wind speed 
is expected to remain elevated over 21-23 Feb due to influence 
from a small equatorial coronal hole rotating towards a geoeffective 
position.

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 20 Feb: G0

Estimated Indices 20 Feb : A   K           
   Australian Region       7   11232222
      Cocos Island         6   11132221
      Darwin               7   11232222
      Townsville           8   22232222
      Learmonth           11   22243223
      Alice Springs        7   11232222
      Gingin               7   21232222
      Canberra             6   01232122
      Hobart               7   11232222    

Estimated Antarctic Regional K Indices 20 Feb :
      Macquarie Island     3   01111122
      Casey               19   34543222
      Mawson              12   22334321

Observed Regional daily pc3 Indices 20 Feb : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Alice Springs        0   (Quiet)
      Gingin               3   (Quiet)
      Canberra             0   (Quiet)
      Hobart               2   (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 20 Feb : A 
           Fredericksburg        12
           Planetary             15                         

Observed AFr/Ap Indices 19 Feb :  A   K
           Fredericksburg         4
           Planetary              5   2001 2212     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
21 Feb    18    G0, chance G1
22 Feb    12    G0
23 Feb     8    G0

COMMENT: G0 geomagnetic conditions were observed in the Australian 
region on UT day 20-Feb. Mostly G0 geomagnetic conditions were 
observed in the Antarctic region, with an isolated period of 
G1 observed at Casey. G0 geomagnetic conditions are expected 
over 21-23 Feb, with a chance of G1 on 21-Feb due to a possible 
glancing impact from a CME first observed on 17-Feb. A high speed 
solar wind stream from a small equatorial coronal hole may contribute 
to geomagnetic activity on 21-Feb.

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
20 Feb      Normal         Normal         Normal         

PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
21 Feb      Normal         Normal-fair    Fair
22 Feb      Normal         Normal         Normal-fair
23 Feb      Normal         Normal         Normal-fair

COMMENT: Normal to fair HF conditions are expected on 21-Feb 
for middle to high latitudes due to possible increased geomagnetic 
activity from a glancing CME impact and influence from a small 
equatorial coronal hole. Mostly normal HF conditions are expected 
over 22-23 Feb. Shortwave fadeouts are possible.

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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
20 Feb   117

Observed Australian Regional MUFs
   Cocos Island Region:
      Near predicted monthly values during local day.
      Enhanced by 15% during local night.
      Enhanced by 55% after local dawn.
   Niue Island Region:
      Enhanced by 15% during local day.
      Enhanced by 25% during local night.
   Northern Australian Region:
      Near predicted monthly values during local day.
      Enhanced by 25% during local night.
   Southern Australian Region:
      Enhanced by 15% during local day.
      Enhanced by 20% during local night.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Enhanced by 20% over the UT day.

Monthly T index:
Month  T index
Jan      119
Feb      75
Mar      76

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
21 Feb   115    Near to 15% above predicted monthly values
22 Feb   115    Near to 15% above predicted monthly values
23 Feb   115    Near to 15% above predicted monthly values

COMMENT: ASWFC Preliminary HF Communications Warning 19 was issued 
on 17 February and is current for 19-21 Feb. Maximum usable frequencies 
(MUFs) in the Australian region on 20-Feb were near predicted 
monthly values to 25% enhanced. MUFs are expected to be near 
predicted monthly values to 15% enhanced over 21-23 Feb, with 
mild degradations possible over 21-22 Feb due to anticipated 
geomagnetic activity. Shortwave fadeouts are possible.

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5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 19 Feb
       Daily Proton Fluence >1 MeV:   1.6E+05
       Daily Proton Fluence >10 MeV:  2.5E+04
       Daily Electron Fluence >2 MeV: 7.50E+06   (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: C1.4

DSCOVR Satellite Solar Wind Day Averaged Data for 19 Feb
Speed: 376 km/sec  Density:    4.0 p/cc  Temp:    36700 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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