Published by the STCE - this issue : 25 Oct 2013. 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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Coronal holes (CH) are regions in the hot solar atmosphere ("corona") where the plasma density at that temperature is very low compared to its surroundings, and thus they look like dark shapes in the corona. Linked to unipolar magnetic fields stretching into space, they are the source of the high-speed solar wind and can create geomagnetic disturbances.
The image underneath is an SDO image (AIA 193) in extreme ultraviolet (EUV) of the solar corona and the coronal hole on 18 July. It is overlaid with white lines that are approximations for the magnetic field lines as deduced from magnetic fields from the solar surface. Clearly, one can see how in the (bright) active regions, the magnetic field lines are bound to the solar surface ("closed" loops), whereas over the coronal hole, the field lines are extending into space ("open").
With the STEREO spacecraft observing the backside of the Sun, forecasters have a permanent view on the evolution of active regions and large scale structures such as coronal holes. This movie at http://www.youtube.com/watch?v=67TdulB0Mw8 covers the period from 1 May till 18 October. It shows a projection of STEREO and SDO EUV imagery of the solar surface onto a flat map. All features transit from east to west (left to right), with the part between -90 and +90 degrees being directed to the Earth. One can see the development and subsequent evolution of the coronal hole. It was largest during its second passage (June), during which it had almost 360 times the surface area of the Earth! It is only now, 4 months later, that STEREO-images indicate this CH has almost completely vanished.
Interestingly, during its first four passages, the high-speed stream brought a whole bunch of high-energy electrons with it (see the STCE Newsletter at http://stce.be/news/207/welcome.html for more details). Satellite operators noted a significant increase in anomalies during these periods, thought to be due to repeated electrostatic discharges. Fortunately, none of the spacecraft was permanently damaged.
Space Weather describes the conditions in space that affect Earth and its technological systems: this sentence is read in less then a minute. But it takes much more time to learn, understand and act. From November 18-22, 2013, over 300 people will discuss it in Antwerp, Belgium at the 10th European Space Weather Week, ESWW.
We have plenary sessions, a discussion on 10 full years of ESWW, tutorial, space weather casino, fair, quiz, ... you name it, we got it.
http://www.stce.be/esww10/
Solar activity was marked by ARs 1861 and 1865 which produced several M-class flares (and countless C-class flares) during the week. The strongest was an M1.8 flare peaking at 08:38 UT on October 15. In the SDO/AIA picture from Oct 10 you see an equatorial coronal hole in the centre of the solar disk, with the two AR behind it.
Geomagnetic conditions ranged from quiet to active during October 14 and 15, due to the influence of a fast speed stream from an equatorial coronal hole. The coronal hole was near the central meridian on Oct 10 as can be seen in the picture above.
The in situ solar wind speed, density and total magnetic field strength measured by the ACE are in the graph below: the dense co-rotating interaction region (CIR) with compressed magnetic field is seen as a bump in the blue and orange curve. The solar wind speed increased gradually after the arrival of the CIR: this is the solar wind blowing from the coronal hole itself.
Solar flare activity fluctuated between low and 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: http://proba2.oma.be/ssa
This page also lists the recorded flaring events.
A weekly overview movie can be found here (SWAP week 186).
http://proba2.oma.be/swap/data/mpg/movies/WeeklyReportMovies/WR186_Oct14_Oct20/weekly_movie_2013_10_14.mp4
Details about some of this week's events, can be found further below.
Eruption on the east limb @ 03:29 - SWAP difference image
Find a movie of the events here (SWAP difference movie)
http://proba2.oma.be/swap/data/mpg/movies/WeeklyReportMovies/WR186_Oct14_Oct20/Events/20131014_Eruption_EastLimb_0329_swap_diff.mp4
Eruption on the south western quadrant @ 13:12 - SWAP difference image
Find a movie of the events here (SWAP difference movie)
http://proba2.oma.be/swap/data/mpg/movies/WeeklyReportMovies/WR186_Oct14_Oct20/Events/20131014_Eruption_SouthWestQuad_1312_swap_diff.mp4
Possible EUV wave on the south western quadrant @ 08:42 - SWAP difference image
Find a movie of the events here (SWAP difference movie)
http://proba2.oma.be/swap/data/mpg/movies/WeeklyReportMovies/WR186_Oct14_Oct20/Events/20131015_PossibleEUVWave_SouthWestQuad_0842_swap_diff.mp4
Large expanding loop on the north western limb @ 06:00 - SWAP difference image
Find a movie of the events here (SWAP difference movie)
http://proba2.oma.be/swap/data/mpg/movies/WeeklyReportMovies/WR186_Oct14_Oct20/Events/20131020_LargeLoop_NorthWestLimb_0600_swap_diff.mp4
Eruption on the north weste quadrant @ 08:54 - SWAP difference image
Find a movie of the events here (SWAP difference movie)
http://proba2.oma.be/swap/data/mpg/movies/WeeklyReportMovies/WR186_Oct14_Oct20/Events/20131020_Eruption_NorthWestQuad_0854_swap_diff.mp4
DAY | BEGIN | MAX | END | LOC | XRAY | OP | 10CM | TYPE | Cat | NOAA |
15 | 0826 | 0838 | 0848 | S22W13 | M1.8 | SN | 87 | III/1 | 5 | 1865 |
15 | 2331 | 2336 | 2341 | S23W20 | M1.3 | 1F | III/1 | 5 | 1865 | |
17 | 1509 | 1541 | 1558 | M1.2 | III/2 | 2 | 1861 |
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 |
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(N61°, 5°E)
b) above Brussels(N50.5°, 4.5°E)
c) in the southern part of Europe(N36°, 5°E)
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
Start : 2013-10-27 - End : 2013-10-31
Magnetic helicity has been intensively studied from
observational, theoretical, and many other aspects of solar
physics. For this meeting we would like to invite solar physicists
who are interested in the observational and theoretical studies of
the helicity, to encourage thorough discussions on the relevant hot
issues. The 1st Helicity Thinkshop was held successfully in 2009,
and now the 2nd one will be held on October 27-31, 2013 in Beijing,
China.
Website:
http://sun.bao.ac.cn/meetings/HT2013/
Start : 2013-10-28 - End : 2013-11-02
The Worshop and School on Radio Sun in Beijing and Inner
Mongolia during Oct.28 - Nov. 2, 2013 is the first international
academic seminar supported by the International Research Staff
Exchange Scheme of the Seventh Fromework Programme of the European
Union (FP7-IRSES-295272-RADIOSUN).
The primary aim of this programme is to establish close research
interaction and collaboration between the key research groups
involved in CSRH, SSRT, and ALMA projects and in development of
relevant theory and data analysis tools, through the systematic
research staff and knowledge exchange, joint research efforts
exploiting existing data and facilities, and preparing the future
world-class partnership in exploitation of the upcoming
facilities.
The Workshop and School welcome all solar physicsts and students
who are interested in solar radio astronomy to participate. We will
discuss and exchange the scientific frontier problems, including
the new-generation radio instruments (CSRH, Siberian
multi-frequency radioheliograph, LOFAR, ALMA, and other new
instruments), recent achievements and their scientific goals;
methods and techniques of data processing (for example, software,
radio image reconstructions, and method for studying various types
of solar radio fine structures); and the objectives of new
observational data and new mathematical methods.
Website:
http://beijingradiosun.csp.escience.cn/
Start : 2013-11-11 - End : 2013-11-22
Magnetic fields play an important role in many astrophysical
processes. But magnetic are difficult to detect and to model or
understand, since the fundamental equations describing the behavior
of magnetized plasmas are highly non-linear. Hence, magnetic fields
are often an inconvenient subject which is overlooked or simply
neglected. Such difficulty burdens the research on magnetic fields,
which has evolved to become a very technical subject, with many
small disconnected communities studying specific aspects and
details.
The school tries to amend the situation by providing a unifying
view of the subject. The students would have a chance to understand
the behavior of magnetic fields in all astrophysical contexts, from
cosmology to the Sun. From star-bursting regions to AGNs in
galaxies. The school will present a balanced yet complete review of
our knowledge. Extensions into the unknown are also important to
indicate present and future lines of research.
The Winter School will bring together in a relaxed working
atmosphere a number of the leading scientists in this field, PhD
students and recent postdocs. The conditions for a successful
interaction will be granted, including two special sessions for
those students that want to present their own work.
Website:
http://www.iac.es/winterschool/2013/
Start : 2013-11-12 - End : 2013-11-15
Since its launch in Sep-2006, more than 600 refereed papers have
been published based on Hinode observations, presenting many new
and important findings to the scientific community. However, due to
the unexpectedly low levels of solar activity, until now the focus
has mainly been on the more quiescent aspects of the solar cycle.
With the solar maximum expected this year, through cooperative
observations with SDO, IRIS, and ground based observatories, Hinode
observations should lead to our understanding of active Sun
phenomena, such as solar flares and CMEs, to be greatly improved.
Making Hinode-7 an excellent opportunity to discuss solar activity
in the current solar cycle and the related science through the use
Hinode data, as well as other solar/space weather data. It will
also be interesting to use this meeting to broaden our focus to
include the solar-stellar connection as a means to deepen our
understanding of solar activity.
Momentum is also gaining for Solar-C, which is being developed
as an international collaboration between Japan, US and Europe. To
further discuss this mission, the Solar-C science meeting will be
held on 11-Nov.
Website:
http://www.kwasan.kyoto-u.ac.jp/hinode-7/
Start : 2013-11-13 - End : 2013-11-13
Most space weather occurs due to the Sun's emissions which
can affect the Earth's space environment. Modern society is
ever more dependent upon ground-based & spaceborne technology
which can be vulnerable to space weather. Satellites, GPS, aviation
& the electric power industry are all at risk from this &
hence space weather is now included on the UK's National Risk
Register. It is important to have long-running, continuous
observations for forecasting, nowcasting & for research in
space weather. This public meeting, held during the peak of the 11
year solar cycle, addresses the deficiency in continuous, long-term
observations & how this might be overcome.
Website:
http://www.rmets.org/events/space-weather-importance-observations
Start : 2013-11-18 - End : 2013-11-22
This International CAWSES-II Symposium hosted by SCOSTEP
(Scientific Committee on Solar-Terrestrial Physics) will provide an
excellent opportunity to discuss the scientific accomplishments of
CAWSES-II and look forward to SCOSTEP's future programs at a moment
toward the end of its five-year period. The symposium will cover
the six major themes of CAWSES-II tasks: 1) What are the solar
influences on the Earth's climate?, 2) How will geospace respond to
an altered climate?, 3) How does short-term solar variability
affect the geospace environment?, 4) What is the geospace response
to variable inputs from the lower atmosphere?, 5) Capacity
Building, 6) Informatics and eScience. The main functions of
CAWSES-II are to help coordinate international activities in
observations, modeling, and applications crucial to achieving this
understanding, to involve scientists in both developed and
developing countries, and to provide educational opportunities for
students of all levels. The symposium offers keynotes/lectures that
will be interesting for all participants every morning and more
specific sessions of presentations in the afternoon. We welcome all
those who are involved and/or interested in CAWSES-II to Nagoya in
the autumn when we will have the pleasure of being surrounded by
beautiful colorful leaves of this season.
Website:
http://www.cawses.org/CAWSES/leaflet_CAWSES-II_120229.pdf
Start : 2013-11-18 - End : 2013-11-22
The 10th Edition of the European Space Weather
Week will take place on 18-22nd
November 2013 in Belgium. The venue will be confirmed early next
year, but mark your calendars now for the 10th Anniversary of this
growing European event.
The ESWW will again adopt the central aim of bringing together
the diverse groups in Europe working on different aspects of Space
Weather
. This includes but isn't
limited to the scientific community, the engineering community,
applications developers, service providers and service end users.
The meeting organisation will again be coordinated by the Belgian
Solar-Terrestrial Centre of Excellence (STCE), ESA
and the Space Weather
Working Team. The local
organisation will be done by the STCE.
Website:
http://www.stce.be/esww10/
Start : 2013-11-26 - End : 2013-11-28
The 1st SPRING (Solar Physics Research Integrated Network Group)
workshop is being held from November 26 - 28, 2013 at the scenic
Brugger's Hotel Park by Titisee hosted by the Kiepenheuer-Institut
für Sonnenphysik in Freiburg, Germany.
The purpose of the workshop is to work on the scientific
requirements for a new ground-based network of telescopes for
full-disk synoptic observations of the Sun.
The desire for such a new network is motivated by new scientific
research directions in solar physics, the requirement of real-time
context data for high-resolution solar telescopes, and the need of
continuous, long-term, consistent, and reliable solar data as
foundation for space weather prediction.
Website:
http://www3.kis.uni-freiburg.de/~mroth/spring.html
Start : 2013-12-13 - End : 2013-12-13
The inclusion of space weather in the National Risk Assessment
in 2012 means that there is now an urgent need for dialogue between
those doing the science of space weather and those using the data
to forecast, understand and mitigate the risks.
Since the Sun is currently at the peak of its cycle - a time
when space weather events become more frequent - we have a timely
opportunity to study how a range of solar activity ultimately lead
to magnetospheric, ionospheric and ground level disturbances.
The goal of this meeting is to bring together those working
across the broad range of space weather activities in the UK to
discuss the current status of observations and recent new advances
in the theories and models of the phenomena of space weather.
Website:
http://www.mssl.ucl.ac.uk/~lmg/spaceweather/Overview.html
Start : 2014-02-10 - End : 2014-02-11
The International Space Weather Initiative (ISWI), with the
support of the United Nations Committee for the Peaceful Uses of
Outer Space, has been very active in promoting the installation of
new ground-based instrumentation in non-traditional locations. In
particular, there has been substantial progress in the observation
of the equatorial ionosphere, solar transients, and energetic
particles from space. In the coming decade these observations will
become available in real time and will be an important new data
source for the forecasting of space weather events. New instruments
are either in the process of deployment, or planned over the next
decade. Similarly, the International Living with a Star (ILWS)
program has been very active coordinating the plans of the world's
space agencies in the planning of new space missions, and in the
development of space weather modeling and forecasting.
Website:
http://newserver.stil.bas.bg/ISWI/Meetings/Cevents.html#item12
Start : 2014-03-16 - End : 2014-03-22
The meeting brings together scientists working in solar physics,
space physics, plasma physics, and astrophysics, in theory,
simulations, and experiment. The objective is to report and discuss
recent progress in our understanding of the fundamental processes
in solar, space, and astrophysical plasmas, in view of heliospheric
in-situ and remote sensing measurements (Van Allen Probe, Themis,
Cluster, Stereo, SDO, Messenger, Cassini, Venus-Express) and remote
sensing astrophysical observations (Chandra, XMM-Newton, Swift and
Fermi Gamma-ray Telescope).
Website:
http://physics.bgu.ac.il/~gedalin/Isradynamics2014/
Start : 2014-06-23 - End : 2014-06-27
The meeting in honour of Prof. Zdenek Svestka will cover issues
of the physics of solar and stellar flares.
Website:
http://solarflares2014.cz/
Start : 2014-08-02 - End : 2014-08-10
The 40th COSPAR Scientific Assembly will be held in Moscow,
Russia from 2 - 10 August 2014. This Assembly is open to all bona
fide scientists.
Website:
http://www.cospar-assembly.org/
Start : 2014-08-31 - End : 2014-09-05
Low-frequency waves (ULF, ELF and VLF) in space plasmas have
been studied for many decades. In our solar system, such waves
occur in the magnetospheres of planets and in the solar wind; more
recently they have also been confirmed on the Sun. In spite of the
great differences in the plasma properties of these regions, the
overarching schemes are wave generation, wave propagation, and wave
dissipation, which are three fundamental aspects of any kind of
waves. A fourth aspect of these waves is their application, either
with direct benefit to humans or for scientific pursuit. Therefore,
this Chapman conference will provide a forum in which various wave
communities can come together and discuss recent achievements of
observational, theoretical, and modeling studies.
Website:
http://chapman.agu.org/spaceplasmas/
Start : 2014-09-08 - End : 2014-09-12
The European Solar Physics Meetings aim to highlight all aspects
of modern solar physics, including observation and theory that span
from the interior of the Sun out into the wider heliosphere. These
meetings provide a broad, yet stimulating, environment for European
and international scientists to share their research in solar
physics.
The meeting will mostly comprise of contributed talks and poster
presentations, with several invited review talks (typically one per
session). Posters will be on display for the whole meeting in close
proximity to the lecture theatre. Refreshments will be served in
the poster viewing area during two dedicated coffee/poster breaks
on each full day.
Website: http://www.espm14.ie/
Start : 2015-06-22 - End : 2015-06-26
The Fourteenth International Solar Wind Conference will be held
for the first time ever in China, from 22 to 26 June 2015, at
Weihai in the Shandong province. It will be jointly organized by
the School of Earth and Space Sciences of Peking University and the
newly-established Institute of Space Sciences of Shandong
University. The meeting will take place in the Space Science
Building of Shandong University, a venue located within walking
distance to the beautiful Weihai International Bathing Beach, one
of the most popular scenic areas of northern China.
The conference will cover all aspects of solar wind physics,
with invited reviews and contributed papers that examine the
current research and outline the future research in all the
relevant solar wind fields.
Website: not available yet