[Ips-dsgr] SWS Daily Report - 17 April 21 issued 2330 UT on 17 Apr 2021
Regional Warning Centre
rwc at ips.gov.au
Sun Apr 18 09:30:07 EST 2021
SUBJ: SWS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 2330UT/17 APRIL 2021 BY Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 17 APRIL AND FORECAST FOR 18 APRIL - 20 APRIL
STATUS INDICATORS SOL:GREEN MAG:GREEN ION: GREEN
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity 17 Apr: Very low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Apr: 75/13
1B. SOLAR FORECAST
18 Apr 19 Apr 20 Apr
Activity Very low to low Very low to low Very low to low
Fadeouts None expected None expected None expected
10.7cm/SSN 78/17 78/17 75/13
COMMENT: Solar activity was very low on UT day 17 April, with
a long duration B-class flare. There are currently three numbered
regions on the visible disk, AR 2814, AR 2815, and AR 2816. Solar
activity is expected to be very low for the next three days,
18-20 April, with a chance of C-class flares. The CME first observed
in LASCO C2 imagery and SDO AIA-171 imagery starting near 17/1556
UT is a limbside event. Based on the location of the CME source,
it is unlikely to impact the earth. On 17 April, the solar wind
speed was mostly near its moderately elevated levels of 600 km/s
in response to a Southern Polar coronal hole with extension into
the low latitudes. The IMF (Bt) range was 2-11 nT and north-south
IMF (Bz) range of +4/-11 nT. The IMF Bz was mostly southward
at the onset of the coronal hole effects, between 17/0000 UT
and 17/0400 UT. The solar wind speed is expected to remain at
moderately enhanced levels today (18 April) due to the coronal
hole effects. The solar wind is expected to begin to gradually
decline from late UT day 19 April as the coronal hole effect
begins to wane.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 17 Apr: Quiet to Active
Estimated Indices 17 Apr : A K
Australian Region 17 33444322
Cocos Island 10 22323322
Darwin 12 33333312
Townsville 17 33444223
Learmonth 21 33444433
Alice Springs 17 33444322
Gingin 20 -3444432
Canberra 18 33543322
Hobart 17 32543322
Estimated Antarctic Regional K Indices 17 Apr :
Macquarie Island 40 34656532
Casey 20 43344324
Mawson 68 76553574
Observed Regional daily pc3 Indices 17 Apr :
Darwin 0 (Quiet)
Townsville 2 (Quiet)
Learmonth 0 (Quiet)
Alice Springs 0 (Quiet)
Gingin 53 (Unsettled)
Canberra 79 (Active)
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 17 Apr : A
Fredericksburg 20
Planetary 30
Observed AFr/Ap Indices 16 Apr : A K
Fredericksburg 15
Planetary 19 2232 4453
2B. MAGNETIC FORECAST
Date Ap Conditions
18 Apr 15 Unsettled to Active
19 Apr 7 Quiet
20 Apr 7 Quiet
COMMENT: SWS Geomagnetic Warning 14 was issued on 16 April and
is current for 17-18 Apr. Mostly quiet to active geomagnetic
conditions were observed in the Australian region on UT day 17
April. Quiet to storm levels were observed in the Antarctic region.
The observed increase in geomagnetic activity is due to the coronal
hole effects. On 18 April, geomagnetic activity is expected to
reach active levels with possible isolated minor storm periods
due to current coronal hole effect. Mostly quiet conditions are
expected from UT day 19 April.
-----------------------------------------------------------
3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
17 Apr Normal Normal Normal-fair
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
18 Apr Normal Normal Normal-fair
19 Apr Normal Normal Normal
20 Apr Normal Normal Normal
COMMENT: Mildly degraded conditions may be observed on 18 April.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
17 Apr 23
Observed Australian Regional MUFs
Cocos Island Region:
No data
Niue Island Region:
No data
Northern Australian Region:
Near predicted monthly values.
Southern Australian Region:
Depressed by 30% during local day.
Enhanced by 25% during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Enhanced by 30% 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
18 Apr 5 Near predicted monthly values/depressed 10 to
30%
19 Apr 0 Near predicted monthly values
20 Apr 10 Near predicted monthly values
COMMENT: SWS HF Communications Warning 11 was issued on 16 April
and is current for 17-18 Apr. MUFs over the Australian regions
were mostly near predicted monthly levels on UT day 17 April.
Mild to moderate MUFs depressions are likely for 18-19 April
due to the observed increase in geomagnetic activity.
-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 16 Apr
Daily Proton Fluence >1 MeV: 3.5E+05
Daily Proton Fluence >10 MeV: 4.3E+04
Daily Electron Fluence >2 MeV: 1.20E+06 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 1%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: A4.8
DSCOVR Satellite Solar Wind Day Averaged Data for 16 Apr
Speed: 434 km/sec Density: 7.6 p/cc Temp: 124000 K Bz: -3 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