Published by the STCE - this issue : 27 Jan 2023. The Solar-Terrestrial Centre of Excellence (STCE) is a collaborative network of the Belgian Institute for Space Aeronomy, the Royal Observatory of Belgium and the Royal Meteorological Institute of Belgium. |
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Last week, solar observers simply had not enough eyes to watch all the sunspots, solar flares and associated coronal mass ejections that were visible. On top of that, also filaments and prominences joined the party. Solar filaments are clouds of charged particles ("plasma") above the solar surface squeezed between magnetic regions of opposite polarity. Being cooler and denser than the plasma underneath and their surroundings, they appear as dark lines when seen on the solar disk and as bright blobs when seen near the solar limb (then they are called "prominences"). Special filters are required to observe these features, and one such a filter is the Hydrogen-alpha (H-alpha) line in the red part of the solar spectrum.
Finally, there was also extreme ultraviolet imagery (30.4 nm) of the filament eruption obtained by the Full Sun Imager (FSI) of Solar Orbiter's EUI instrument (https://www.sidc.be/EUI/intro ). On 20 January, SolO was at about the same distance from the Sun as the Earth (141.5 vs 147.2 million kilometer), trailing our planet by about 27 degrees. It thus provided a more oblique view of this specific filament eruption.
Plasmasphere Ionosphere Thermosphere Integrated Research Environment and Access services is a European Network of Research Facilities (PITHIA-NRF) that integrates observing facilities, data processing tools and prediction models dedicated to ionosphere, thermosphere and plasmasphere research.
PITHIA-NRF invites applications for access to a variety of research facilities for studies and modeling of physical processes acting in the Earth’s upper atmosphere, with support from experts within the field.
The call is running from 15 January 2023 until 15 June 2023. It is an Open Call and applications will be handled as they arrive to streamline the timelines of the projects.
More at https://pithia-nrf.eu/pithia-nrf-users/tna/tna-calls/fourth-tna-call.
The solar flaring activity was low to moderate with background C-class flaring and several M-class flares. There were fourteen numbered active regions on the visible disk, that produced 39 C-class flares and 7 M-class flares. The X-ray flux background was at the C level during the whole week. The largest flare over the week was a M4.9 flare, peaking at 14:31 UTC on Jan 15, associated with the active region NOAA 3190.
A slow south-east coronal mass ejection (CME) related to the M-class flare from NOAA AR 3190 was detected in LASCO C2 imagery at 16:36 UT on Jan 15. The eruption was not expected to have an Earth-directed component.
A partial halo CME directed towards the south-west was seen in LASCO C2 imagery from 13:36 UTC on January 18. This was determined to be a back-sided event and no impact at Earth was expected.
A filament eruption in the southwestern quadrant was observed on Jan 20 around 12:30UTC. The associated CME was seen in SoHO/LASCO C2 coronagraph data from 12:24UTC. The ejection was directed south-west.
Another filament erupted shortly after at around 13:47UTC. It was related to a C5.3 flare from NOAA AR 3190. The associated faint CME, that appears in SoHO/LASCO C2 coronagraph data from 14:48UTC onwards, was directed to the south.
An equatorial positive polarity coronal hole was transiting the central meridian at the start of the week. Furthermore, an equatorial coronal hole with positive polarity crossed the central meridian on Jan 21.
The greater than 10 MeV proton flux was slightly elevated on Jan 20 following filament eruption and related CME activity but remained under radiation storm levels throughout the entire week. The greater than 2 MeV electron flux was below the 1000 pfu threshold throughout the entire the week. The corresponding electron fluence was at nominal levels.
The solar wind was slightly elevated. The magnetic field was predominantly directed away from the Sun. On Jan 17, an ICME was seen in the solar wind at L1. The total magnetic field carried by the ICME was maximum 15 nT and minimum -12 nT. The speed of the ICME was around 430 km/s.
The high speed stream from a positive coronal hole arrived in the L1 point on Jan 20. The solar wind speed followed an increasing trend, rising from 350 km/s to 540 km/s. The total interplanetary magnetic field was between 7 nT to 10 nT. The Bz ranged between -8 to 7 nT.
On Jan 15, geomagnetic conditions were quiet to active over Belgium and reached minor storm level on the global scale.
From Jan 16 the geomagnetic conditions over Belgium were mostly quiet to unsettled.
On Jan 18, active conditions were measured in Belgium. Globally the geomagnetic conditions given by the NOAA Kp index reached active levels. This was in response to an ICME arrival.
On Jan 21, the global geomagnetic field became active, probably as response on the high speed stream.
DAY | BEGIN | MAX | END | LOC | XRAY | OP | 10CM | TYPE | Cat | NOAA |
17 | 2316 | 2329 | 2344 | M1.8 | VI/2 | 48 | 3190 | |||
18 | 1021 | 1035 | 1052 | M1.8 | 48 | 3190 | ||||
19 | 0400 | 0403 | 0409 | N11E43 | M1.1 | SF | 52 | 3196 | ||
19 | 1006 | 1012 | 1019 | M1.7 | III/2 | 52 | 3196 | |||
19 | 1026 | 1027 | 1029 | N11E43 | M1.0 | SF | 52 | 3196 | ||
22 | 1212 | 1226 | 1234 | M1.1 | 48 | 3190 | ||||
22 | 1649 | 1702 | 1710 | S26W51 | M1.6 | 1B | 46 | 3194 |
LOC: approximate heliographic location | TYPE: radio burst type |
XRAY: X-ray flare class | Cat: Catania sunspot group number |
OP: optical flare class | NOAA: NOAA active region number |
10CM: peak 10 cm radio flux |
Solar flare activity fluctuated from low to moderate during the week.
In order to view the activity of this week in more detail, we suggest to go to the following website from which all the daily (normal and difference) movies can be accessed: https://proba2.oma.be/ssa
This page also lists the recorded flaring events.
A weekly overview movie can be found here (SWAP week 669). https://proba2.sidc.be/swap/data/mpg/movies/weekly_movies/weekly_movie_2023_01_16.mp4
Details about some of this week's events can be found further below.
If any of the linked movies are unavailable they can be found in the P2SC movie repository here https://proba2.sidc.be/swap/data/mpg/movies/
The daily Estimated International Sunspot Number (EISN, red curve with shaded error) derived by a simplified method from real-time data from the worldwide SILSO network. It extends the official Sunspot Number from the full processing of the preceding month (green line), a few days more than one solar rotation. The horizontal blue line shows the current monthly average. The yellow dots give the number of stations that provided valid data. Valid data are used to calculate the EISN. The triangle gives the number of stations providing data. When a triangle and a yellow dot coincide, it means that all the data is used to calculate the EISN of that day.
Local K-type magnetic activity index for Belgium based on data from Dourbes (DOU) and Manhay (MAB). Comparing the data from both measurement stations allows to reliably remove outliers from the magnetic data. At the same time the operational service availability is improved: whenever data from one observatory is not available, the single-station index obtained from the other can be used as a fallback system.
Both the two-station index and the single station indices are available here: http://ionosphere.meteo.be/geomagnetism/K_BEL/
The Space Weather Briefing presented by the forecaster on duty from Jan 15 to 22. It reflects in images and graphs what is written in the Solar and Geomagnetic Activity report: https://www.stce.be/briefings/20230123_SWbriefing.pdf
The figure shows the time evolution of the Vertical Total Electron Content (VTEC) (in red) during the last week at three locations:
a) in the northern part of Europe(N 61deg E 5deg)
b) above Brussels(N 50.5deg, E 4.5 deg)
c) in the southern part of Europe(N 36 deg, E 5deg)
This figure also shows (in grey) the normal ionospheric behaviour expected based on the median VTEC from the 15 previous days.
The VTEC is expressed in TECu (with TECu=10^16 electrons per square meter) and is directly related to the signal propagation delay due to the ionosphere (in figure: delay on GPS L1 frequency).
The Sun's radiation ionizes the Earth's upper atmosphere, the ionosphere, located from about 60km to 1000km above the Earth's surface.The ionization process in the ionosphere produces ions and free electrons. These electrons perturb the propagation of the GNSS (Global Navigation Satellite System) signals by inducing a so-called ionospheric delay.
See http://stce.be/newsletter/GNSS_final.pdf for some more explanations ; for detailed information, see http://gnss.be/ionosphere_tutorial.php
Check out our activity calendar: activities and encounters with the Sun-Space-Earth system and Space Weather as the main theme. We provide occasions to get submerged in our world through educational, informative and instructive activities.
If you want your event in our calendar, contact us: stce_coordination at stce.be
* January 27, Seminar: Opportunities of Wikipedia and related applications for science, BIRA-IASB
* January 30, 31, February 2, 3, Space Weather Introductory Course - online, by the STCE, zoom
* January 31, CmPA Seminar: Torsional Alfvén waves can trigger turbulence in nonuniform coronal loops, Leuven, Belgium
* February 2, STCE seminar: Bursts and bombs in the solar atmosphere, Brussels, Belgium
* February 17, STCE seminar: Point spread function corrections in solar physics, Brussels, Belgium
* March 14, PITHIA-NRF High Profile Meeting, Brussels, Belgium
* March 15, PITHIA-NRF Innovation Day, Brussels, Belgium
* March 16, PITHIA-NRF Training for Partners, Brussels, Belgium
* March 17, PITHIA-NRF Workshop for Optimization of Observational Strategies, Brussels, Belgium
* March 27-29, Space Weather Introductory Course - onsite, by the STCE, Brussels, Belgium - FULL
* May 22-24, Space Weather Introductory Course - onsite, by the STCE, Brussels, Belgium - FULL
* May 29 - June 1, PITHIA-NRF Training School, Rome, Italy
Check: https://www.stce.be/calendar