[Ips-dsgr] SWS Daily Report - 25 April 21 issued 2333 UT on 25 Apr 2021
rwc
rwc at ips.gov.au
Mon Apr 26 09:33:19 EST 2021
SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/25 APRIL 2021 BY Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 25 APRIL AND FORECAST FOR 26 APRIL - 28 APRIL
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 25 Apr: Low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Apr: 79/19
1B. SOLAR FORECAST
26 Apr 27 Apr 28 Apr
Activity Low Low Low
Fadeouts None expected None expected None expected
10.7cm/SSN 79/19 78/17 78/17
COMMENT: Solar activity was low on UT day 25 April with multiple
B-class flares and a C2 flare. The C2 flare was from region 2816
at 25/0135UT. There are currently five numbered regions on the
visible disk, ARs 2816, 2818, 2819, 2820 and 2821. SOHO and Stereo-A
images showed a series of small, narrow CMEs starting at 25/0209UT
most likely associated with the C2 flare from region 2816 and
probably some small filament eruptions from the SW quadrant observed
in H-alpha images. There was another filament eruption in the
SE quadrant in SDO images after 25/1248UT with a corresponding
CME that was observed in the coronagraph images. Further analysis
is required to determine if the CME activity has any Earth directed
component. No other Earth directed CMEs were observed in the
available images. Solar activity is expected to be low for the
next three UT days, 26-28 April with a slight chance of an M-class
flare. On UT day 25 April, the solar wind speed remained slightly
enhanced between 450 km/s and 500 km/s after the arrival of the
CME from 22 April at 24/2220UT. The IMF (Bt) ranged from 5 nT
to 10 nT and the north-south IMF (Bz) range was +5/-8 nT. The
IMF Bz component sustained a southward orientation for about
12 hours after the CME arrived. These enhanced solar wind conditions
are expected to continue on UT day 26 April as the CME passes.
Then the solar wind speed is expected to start decreasing back
to nominal levels on UT days 27-28 April. ACE EPAM data indicates
an energetic ion enhancement event beginning 25/1900UT, which
can be a precursor to increased geomagnetic activity over next
24-36 hours.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 25 Apr: Quiet to Active
Estimated Indices 25 Apr : A K
Australian Region 12 42333131
Cocos Island 9 42222131
Darwin 9 32233121
Townsville 12 42333122
Learmonth 15 52333131
Alice Springs 10 42233121
Gingin 11 -3233231
Canberra 12 42333131
Hobart 16 42344232
Estimated Antarctic Regional K Indices 25 Apr :
Macquarie Island 30 54365231
Casey 15 53422222
Mawson 53 76443265
Observed Regional daily pc3 Indices 25 Apr :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 2 (Quiet)
Canberra 5 (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 25 Apr : A
Fredericksburg 18
Planetary 21
Observed AFr/Ap Indices 24 Apr : A K
Fredericksburg 10
Planetary 12 3333 2323
2B. MAGNETIC FORECAST
Date Ap Conditions
26 Apr 15 Quiet to active
27 Apr 10 Quiet to Unsettled
28 Apr 7 Mostly quiet
COMMENT: SWS Geomagnetic Warning 16 was issued on 24 April and
is current for 26 Apr only. Geomagnetic conditions in the Australian
region were at quiet to active levels with one minor storm period
at Learmonth station on UT day 25 April. Storm levels were observed
in the Antarctic region. Mostly quiet to unsettled conditions
with possible active periods are expected on UT day 26 April
as CME effects persist. Then mostly quiet to unsettled conditions
are expected on UT day 27 April and mostly quiet conditions on
UT day 28 April.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
25 Apr Normal Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
26 Apr Normal Normal-fair Normal-fair
27 Apr Normal Normal-fair Normal-fair
28 Apr Normal Normal Normal
COMMENT: Minor to moderate degradation in HF propagation conditions
may be observed on UT days 26-27 April. Mostly normal HF propagation
conditions are expected on UT day 28 April.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
25 Apr 24
Observed Australian Regional MUFs
Cocos Island Region:
No data available.
Niue Island Region:
No data available.
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Near predicted monthly values.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Enhanced by 15% 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
26 Apr 10 Near predicted monthly values/depressed 10 to
20%
27 Apr 10 Near predicted monthly values/depressed 10 to
20%
28 Apr 20 Near predicted monthly values
COMMENT: SWS HF Communications Warning 12 was issued on 24 April
and is current for 25-27 Apr. MUFs in the Australian region on
UT day 25 April were mostly near predicted monthly values. Minor
MUF depressions are possible on UT days 26-27 April due to the
rise in geomagnetic activity. MUFs are expected to be mostly
near predicted monthly values on UT day 28 April.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 24 Apr
Daily Proton Fluence >1 MeV: 6.8E+04
Daily Proton Fluence >10 MeV: 4.3E+04
Daily Electron Fluence >2 MeV: 1.80E+08 (moderate fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability:14%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: B1.3
DSCOVR Satellite Solar Wind Day Averaged Data for 24 Apr
Speed: 465 km/sec Density: 5.2 p/cc Temp: 151000 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
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