[Ips-dsgr] SWS Daily Report - 22 April 21 issued 2330 UT on 22 Apr 2021
Regional Warning Centre
rwc at ips.gov.au
Fri Apr 23 09:30:10 EST 2021
SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/22 APRIL 2021 BY Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 22 APRIL AND FORECAST FOR 23 APRIL - 25 APRIL
STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: GREEN
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 22 Apr: Low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 22 Apr: 84/26
1B. SOLAR FORECAST
23 Apr 24 Apr 25 Apr
Activity Low Low Low
Fadeouts Possible Possible Possible
10.7cm/SSN 84/26 84/26 82/23
COMMENT: Solar activity was low on UT day 22 April. There are
currently three numbered regions on the visible disk, AR2816,
AR2817 and AR2818. There were a series of B-class and C-class
flares from regions 2816 and 2817. A C3.8 flare from region 2816
at 0435UT produced a CME that looks to be directed towards the
Earth. Further analysis about this CME is in progress. Today's
largest flare was a C8.5 flare from region 2817 at 2011 UT. No
other earthward directed CMEs were observed. Solar activity is
expected to be low for the next three UT days, 23-25 April with
C-class flares possible during this period and a slight chance
of an isolated M-class event. On UT day 22 April, the solar wind
speed followed a decreasing trend from 470 km/s down to 400 km/s
due to waning coronal hole effects. The IMF (Bt) peaked at 4
nT and the north-south IMF (Bz) range was +/-3 nT. The solar
wind speed is expected to continue gradually decreasing until
another equatorial coronal hole moves into geoeffective position
on UT day 23 April, elevating the solar wind speed to moderately
enhanced levels again through UT day 24 April. The early estimations
indicate that the CME, that is associated with the 22/0425UT
C3.8 flare, is expected to arrive at Earth on UT day 25 April.
A joint effect of this CME along with the coronal hole effect
may result in strong enhancements to the solar wind parameters.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 22 Apr: Quiet
Estimated Indices 22 Apr : A K
Australian Region 3 11122001
Cocos Island 1 11011000
Darwin 2 11112001
Townsville 4 11222011
Learmonth 3 11123000
Alice Springs 2 11112000
Gingin 3 00123001
Canberra 3 01222001
Hobart 3 01222000
Estimated Antarctic Regional K Indices 22 Apr :
Macquarie Island 7 02234000
Casey 4 22222001
Mawson 15 43331015
Observed Regional daily pc3 Indices 22 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 0 (Quiet)
Canberra 6 (Quiet)
Melbourne NA
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 22 Apr : A
Fredericksburg 5
Planetary 5
Observed AFr/Ap Indices 21 Apr : A K
Fredericksburg 7
Planetary 7 2332 2111
2B. MAGNETIC FORECAST
Date Ap Conditions
23 Apr 10 Quiet to unsettled with possible active periods
24 Apr 15 Quiet to unsettled with possible active periods
25 Apr 23 Unsettled to active with a possible G1 minor
storm
COMMENT: Mostly quiet geomagnetic conditions were observed in
the Australian region on UT day 22 April. Quiet to active levels
were observed in the Antarctic region. Geomagnetic activity is
expected to be initially at quiet to unsettled levels until another
equatorial coronal hole moves into geoeffective position on UT
day 23 April, causing mostly quiet to unsettled conditions with
possible active periods through UT day 24 April. The CME from
the 22/0425UT C3.8 flare is estimated to arrive at Earth around
mid-day on UT day 25 April causing further rise to the geomagnetic
activity possibly up to G1 minor storm levels.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
22 Apr Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
23 Apr Normal Normal Normal
24 Apr Normal Normal Normal-fair
25 Apr Normal-fair Normal-fair Fair
COMMENT: Mostly normal HF propagation conditions are expected
on UT day 23 April. Periods of minor degradation may be observed
on UT day 24 April at high latitudes. Moderate degradation in
HF propagation conditions are possible on UT day 25 April.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
22 Apr 15
Observed Australian Regional MUFs
Cocos Island Region:
No data available.
Niue Island Region:
No data available during.
Northern Australian Region:
Near predicted monthly values during local day.
Depressed by 25% 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
Mar 9
Apr 19
May 23
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
23 Apr 15 Near predicted monthly values
24 Apr 5 Near predicted monthly values/depressed 10 to
15%
25 Apr 0 Depressed 10 to 20%/near predicted monthly values
COMMENT: MUFs in the Australian region on UT day 22 April were
mostly near predicted monthly values with some moderate depressions
in the Northern Australian region during the local night. MUFs
are expected to be near predicted monthly values on UT day 23
April. Minor to mild MUF depressions are possible on UT days
24 April due to expected rise in geomagnetic activity. Moderate
MUF depressions may be observed on UT day 25 April due to expected
further rise in geomagnetic activity.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 21 Apr
Daily Proton Fluence >1 MeV: 6.5E+04
Daily Proton Fluence >10 MeV: 4.2E+04
Daily Electron Fluence >2 MeV: 5.50E+08 (high fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:24%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B1.2
DSCOVR Satellite Solar Wind Day Averaged Data for 21 Apr
Speed: 527 km/sec Density: 5.8 p/cc Temp: 265000 K Bz: 0 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
IMPORTANT: This e-mail, including any attachments, may contain,
confidential or copyright information. The views expressed in
this message are those of the individual sender, unless
specifically stated to be the views of SWS. If you are not
the intended recipient, please contact the sender immediately
and delete all copies of this e-mail and attachments.
To unsubscribe from an IPS mail list either send an email to
"MAIL_LIST"-leave at ips.gov.au or go to
http://www.sws.bom.gov.au/mailman/listinfo/"MAIL_LIST".
Information about training can be obtained from
http://www.sws.bom.gov.au/mailman/listinfo/ips-training.
General information is available from
http://www.sws.bom.gov.au/mailman/listinfo/ips-info.
More information about the ips-dsgr
mailing list