SIDC Weekly Bulletin

:Issued: 2023 Nov 28 1916 UTC
:Product: documentation at http://www.sidc.be/products/bul
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# SIDC Weekly bulletin on Solar and Geomagnetic activity             #
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WEEK 1195 from 2023 Nov 20

Solar Active Regions (ARs) and flares
---------------
There were 14 active regions visible throughout the week (NOAA ARs 3489 to
3503). The majority of them had a simple alpha or beta magnetic field
configuration at the start of the week, while more complex regions, such as
NOAA AR 3500 (beta-gamma-delta) were visible at the second half of the
week. Four M-class flares were measured. The strongest flare was an M1.5
from NOAA AR 3489, peaking at 03:38 UTC on 23 November.

Coronal mass ejections
---------------------
Numerous CMEs per day occurred. Three of them had a slight chance of a
glancing blow to Earth. A shock was observed in the solar wind parameters
at 07:55 UTC on November 25, possibly from the CME seen in LASCO C2 at
06:48UT on November 22.

Coronal Holes
---------------------
Four coronal holes were on-disk during the week, with two of them crossing
central meridian on November 21 and 23, one with negative polarity at mid
southern latitudes and an a mid northern latitudinal one with positive
polarity.

Proton flux levels
---------------------
The 10 MeV GOES proton flux was below threshold the full week.

Electron fluxes at GEO
---------------------
The greater than 2 MeV electron flux was below the 1000 pfu threshold, as
measured by GOES 16 from the majority o the week, with exception November
24, when it crossed the 1000 pfu threshold. The 24 hour electron fluence
was at normal levels.

Solar wind
---------------------
At the start of the the week transient features and influences from the
high latitudes northern polarity coronal holes appeared to be influencing
the solar wind parameters. On November 22, the high speed stream from the
eastern mid latitudinal positive polarity coronal hole was apparent, with
values returning towards background levels by November 24. The week ended
with the possible arrival of the ICME at  07:55 UTC on November 25 possibly
from the CME seen in LASCO C2 at 06:48UT on November 22, combined with the
high speed stream from the mid latitudinal positive polarity coronal hole
that crossed central meridian on November 23.

Geomagnetism
---------------------
Geomagnetic conditions reached moderate storm levels globally and locally
(Kp 6 and K_Bel 6) late November 25. This was due to the the combined
effects of the ICME with the high speed stream.

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DAILY INDICES
DATE           RC   EISN  10CM   Ak   BKG    M   X
2023 Nov 20   119    103   157   004   C1.5   1   0   
2023 Nov 21   193    166   172   018   C1.7   0   0   
2023 Nov 22   ///    169   190   034   C2.7   0   0   
2023 Nov 23   ///    186   194   006   C2.3   2   0   
2023 Nov 24   205    180   178   010   C1.2   1   0   
2023 Nov 25   ///    180   176   042   C1.1   0   0   
2023 Nov 26   ///    188   180   010   C1.0   0   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)
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NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX  END  LOC    XRAY OP  10CM Catania/NOAA RADIO_BURST_TYPES 
20  0854  0903 0912 ////// M1.2          ///3492      

23  0259  0338 0405 ////// M1.4          ///////      III/1VI/2 

23  1425  1437 1442 ////// M1.0          54/3490      III/2 

24  0917  0933 0943 S16W02 M1.1 1F       53/3499      VI/2III/2 

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