SIDC Weekly Bulletin

Review of past solar and geomagnetic activity.
Source SIDC (RWC-Belgium)
Frequency Weekly
Format Plain text
Mail header SIDC Weekly Bulletin
SIDC code bul

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:Issued: 2024 Feb 26 1529 UTC
:Product: documentation at http://www.sidc.be/products/bul
#--------------------------------------------------------------------#
# SIDC Weekly bulletin on Solar and Geomagnetic activity             #
#--------------------------------------------------------------------#
WEEK 1208 from 2024 Feb 19

Solar Active Regions (ARs) and flares
---------------
Solar flaring activity over the past week started at low levels, went to
high levels on February 21 and February 22 and then went to moderate levels
until the end of the week. There were 9 active regions visible throughout
the week and 39 C-class flares, 8 M-class flares and 3 X-class flare were
recorded. The strongest flare being a X6.3-flare with peak time 22:35 UTC
on February 22; the second strongest was a X1.8-flare, with peak time 23:07
UTC on February 22 and the third strongest was X1.7-flare with peak time
06:32 UTC on February 22, all were associated with NOAA AR 3590. Most of
the flaring activity came from NOAA AR 3590 which was the largest and most
magnetically complex (beta-gamma-delta) region on the disk throughout the
week. NOAA AR 3592 produced one out of the 8 M-class flares all other
M-class flares were produced by NOAA AR 3590.

Coronal mass ejections
---------------------
There were two partial halo Coronal Mass Ejections (CME)s observed during
the week. The first halo CME, was south-east directed and detected in LASCO
C2 data at 16:12 UTC on February 21. It was associated with an eruption
behind the east limb and did not impact the Earth. The second westward
partial halo CME, was detected in LASCO C2 data at 18:36 UTC on February
21. It was associated with a filament eruption seen in SDO/AIA 304 and 193
at 17:37 on February 21 in the north-west quadrant of the visible solar
disk. The CME had an estimate plane-of-sky speed of around 450 km/s and had
a glancing blow arrival at Earth on February 25.

Coronal Holes
---------------------
Two negative polarity coronal holes crossed the central meridian on
February 23. One in the in the northern half of the Sun at high latitudes
and the other was a recurring coronal hole in the southern hemisphere of
the Sun at low latitude. The Earth came under the influence of a
high-speed-stream from the southern coronal hole on February 24.

Proton flux levels
---------------------
At the start of the week the greater than 10 MeV GOES proton flux was
enhanced but below threshold levels due to X2.5-flare on February 12 it
continued to gradually decrease until reaching nominal levels on February
25.

Electron fluxes at GEO
---------------------
The greater than 2 MeV electron flux measured by GOES-16 was at background
levels throughout the week.  The 24h electron fluence was at nominal levels
throughout the week.

Solar wind
---------------------
From the beginning of the week the solar wind parameters registered nominal
slow solar wind conditions until February 24 when the solar wind parameters
become disturbed under the influence of a high-speed-stream from a negative
polarity coronal hole and the arrival of a ICME. A shock in the solar wind
marked the arrival of the high-speed stream. The solar wind speed jumped
from around 309 km/s to around 380 km/s and the interplanetary magnetic
field jumped from 5 nT to 10 nT at 16:20 UTC on February 24. At around
00:40 UTC on February 25 the Earth came under the influence of a ICME after
which the solar wind speed reached maximum values of around 450 km/s and
the interplanetary magnetic field reached a value of 11 nT, with a minimum
Bz value of -10 nT. At the start of the week the phi-angle was mainly in
the positive sector (directed away from the Sun) with periods in the
positive sector until February 23 when it switched to the negative sector.

Geomagnetism
---------------------
The geomagnetic conditions over the past week were quiet globally and
locally (Kp 1-2 and K Bel 1-2) with some unsettled periods (Kp 3)
throughout the week.

---------------------------------------------------------------------------
DAILY INDICES
DATE           RC   EISN  10CM   Ak   BKG    M   X
2024 Feb 19   ///    073   152   002   C1.1   0   0   
2024 Feb 20   ///    051   153   007   C1.1   0   0   
2024 Feb 21   ///    049   170   003   C1.0   1   1   
2024 Feb 22   073    054   173   005   C1.7   1   2   
2024 Feb 23   134    107   173   003   C2.6   3   0   
2024 Feb 24   ///    104   179   008   C1.6   4   0   
2024 Feb 25   ///    115   181   011   C1.4   1   0   
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# RC   : Sunspot index (Wolf Number) from Catania Observatory (Italy)
# EISN : Estimated International Sunspot Number
# 10cm : 10.7 cm  radioflux (DRAO, Canada)
# Ak   : Ak Index Wingst (Germany)
# BKG  : Background GOES X-ray level (NOAA, USA)
# M,X  : Number of X-ray flares in M and X class, see below (NOAA, USA)
---------------------------------------------------------------------------

NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX  END  LOC    XRAY OP  10CM Catania/NOAA RADIO_BURST_TYPES 
21  2252  2307 2314 ////// X1.8          ///3590      

21  2358  0014 0031 ////// M1.5          ///////      

22  0617  0632 0640 N16E35 X1.7 2B       85/3590      

22  2029  2046 2103 N18E29 M4.8 2B       85/3590      

22  2208  2234 2243 ////// X6.3          85/3590      III/1 

23  1312  1328 1354 ////// M1.0          85/3590      

23  1541  1553 1606 N18E18 M1.4 1N       85/3590      

23  1726  1747 1807 N18E18 M2.6 1N       85/3590      III/2 

24  0621  0634 0644 ////// M4.5          85/3590      

24  1032  1057 1103 ////// M2.2          85/3590      

24  1103  1118 1125 ////// M3.6          85/3590      

24  1154  1159 1204 ////// M1.0          85/3590      

25  1647  1722 1747 N17W10 M2.0 1N       85/3590      CTM/1 

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Details

This report is sent once a week, typically on a monday.
The weekly bulletin gives an overview of solar and geomagnetic activity of the past week and includes a noticeable solar events list.
Check the ISES code book for information on ISES codes.