Seminars & Internal Meetings
Seminars are held remotely Thursdays 14:00. Contact us if you whish to be included in the mailing list.
Seminars in 2020 and earlier are listed below:
Speaker: Andres Spicher (with contributions from a long list of co-authors)
Title: High latitude ionospheric density irregularities
Plasma density irregularities with scale-sizes ranging from hundreds of kilometers down to a few meters are common in the high-latitude ionosphere. The irregularities generally peak around the cusp and auroral regions, and can have significant space weather impacts, as they can degrade Global Navigation Satellite System (GNSS) radio signals by causing amplitude and phase scintillations. As the physical causes and detailed formation are still unresolved, characterizing density irregularities and their sources is of significant interest, and will be essential to develop models for predicting scintillations. In this seminar, we briefly review the physical processes generally regarded as dominant for causing macro-scale density irregularities at F region altitudes. We then present selected studies (based on both in situ and ground-based instruments) examining different sources of free energy and the applicability and relevance of different instability modes. Finally, observations and analysis necessary to advance the fields will be discussed.
Margareta Myrvang and Johann Stamm
Dette foredraget handler opp soppens spennende verden. Hensikten med foredraget er å gjøre dere til potensielt litt mer selvsikre og selvstendige sopplukkere. Vi vil blant annet snakke om hvor det er lurt å lete etter sopp, noe som varierer mellom de ulike artene. Noen sopper foretrekker barskog, andre løvskog og noen vokser på enger. Et par arter er ikke så kresne og vokser både her og der. I foredraget nevner vi også hva dere bør ta med av utstyr på sopptur. Vi vil i tillegg snakke om hvordan man unngår giftige sopper. Selvfølgelig nevner vi noen gode matsopper. Til slutt en liten quiz!
Title: Svalbard - a hot-zone within space physics. You can/should also go there and study.
Longyearbyen, situated at the Svalbard archipelago is a hot spot for researchers and aspiring space physicists. In terms of space physics, it is uniquely located within the cusp region of the magnetosphere which makes it an ideal place for observing cusp dynamics – an area of ongoing research; the importance of which is emphasized by the Grand Challenge Initiative. Because of this, Svalbard houses several observatory facilities, some of which are The EISCAT Svalbard radar, the Kjell Henriksen Observatory and a sounding rocket range. Here you also find the University Centre in Svalbard (UNIS), which is an educational facility owned by the 5 main universites of Norway. At UNIS you can take courses within space physics, write your thesis and become an expert on arctic geophysics. You will also become acquainted with researches from all over the world, both within the field of space physics and without. In this talk I present to you why Svalbard is such an interesting place, and argue why you should utilize the opportunity to go there.
Title: Dynamic aurora - how to calculate the ionospheric responses when things happen quickly (Part 2/2)
Title: Dynamic aurora - how to calculate the ionospheric responses when things happen quickly (Part 1/2)
Abstract: In dynamic aurora the intensity can vary at sub-second
time-scales. The ionospheric response to the different types of
rapidly varying aurora share some characteristics that are different to
the case of stable auroral arcs. In this talk examples of such auroras
will be presented. To calculate the auroral brightness for such fast
variations it is necessary to take into account the time it takes
high-energy electrons to move from the source-altitude (typically a
few thousand kilometres) down to and through the upper atmosphere (down
to about 100 km altitude), and the time it takes for these electrons to
lose their energy. A new "auroral electron-transport" model
that takes these effects into account have been developed. Previous
steady-state electron-transport models could not resolve
time-variations of the precipitation. This novel model allows us to
determine time-variations in electron-fluxes which makes it possible
to predict small time-shifts between auroral emission. Comparisons
with optical data show the prediction to be consistent with
Friday 22 November 13:15 - Seminar room FPARK 289 - Forskningsparken
University of Bordeaux, France
Modeling the electron collision frequency during solid-to-plasma transition of polystyrene for direct-drive inertial confinement fusion applications
Wednesday 13 November 14:00 - Seminar room - Forskningsparken
Professor T. W. Hartquist
School of Physics and Astronomy, University of Leeds, United Kingdom
Astronanophysics and Astromicrophysics – Dust in the Cosmos
The talk will provide examples of the variety of cosmic environments in which dust exists and plays roles in governing the physical and chemical properties. It will also contain a review of work done in Leeds on the effects of dust on the dynamics of shocks in dusty star forming regions and on methods for treating the evolution of the grain size distribution in a region where destruction and agglomeration occur. It will cover: the basic properties of interstellar dust; the formation and role of dust in stellar outflows; surface chemistry and dusty magnetohydrodynamics in star forming regions; protoplanetary disc formation; presolar grains and meteoroids; dust near the terrestrial mesopause; some dust dynamics in Saturn’s rings.
Wednesday 18 September 10:00 - Seminar room - Forskningsparken
Dr. Alexander Koloskov
Institute of Radio Astronomy National Academy of Sciences of Ukraine, Kharkiv, Ukraine, State Institution National Antarctic Scientific Center Ministry of Education and Science of Ukraine, Kyiv, Ukraine
Near earth environment monitoring using radio signals from ELF to L-band
The work presents an overview of results of experimental investigations of the processes occurred in the Earth's ionosphere and ELF radio diagnostics of the world thunderstorm activity obtained in the Institute of Radio Astronomy National Academy of Sciences of Ukraine. We analyzed the data of long-term monitoring observations by HF Doppler receivers, ionosondes, GNSS receivers, induction-coil and fluxgate magnetometers performed in the region of Antarctic Peninsula (Vernadsky, Ukrainian Antarctic Station), mid-latitudes (Ukraine) and Arctic (Svalbard and Tromso). The data of other instruments like IS radars were used during the special measuring campaigns.
The technique of multi-position Doppler observation was implemented for studying of the ionospheric heating and for analysis of HF radio signal propagation effects on long and super-long radio paths. To study AGW/TID phenomena both HF Doppler sounding and GNSS-TEX measurements were used.
Another area of research is systematic observation and analysis of electromagnetic noise in ULF-ELF bands. The work shows the results of monitoring observation of Schumann resonance phenomenon performed in the Antarctic and in the Arctic. Schumann signals that formed by radio emission from every lightning discharge of the planet might be used to monitor the global temperature in the atmosphere and state of the lower ionosphere over the whole globe. The work presents and discusses the effect of interannual variation of the first Schumann mode intensity occurred in-phase with 11-years solar activity cycle that was discovered at Vernadsky. The sporadic solar activity effect on the parameters of Schumann signals was analyzed as well. The behavior of Schumann resonance parameters observed in different hemispheres is interpreted. The work demonstrates also that a point source model might be effectively used to estimate the activity of global thunderstorms’ centers. The technique of powerful lightning strokes location using the Antarctic and the Arctic ELF records was illustrated by the results of one-year data processing.
Monday 5 August 2019, 14:00 - Realfagbygget, room B203
Dr. Katherine Rosenfeld
MIT Lincoln Laboratories, USA
Katherine talks about her PhD project: Applications of High-Resolution Observations of Millimeter Wavelengths
Interferometric observations at millimeter wavelengths provide a precious, detailed view of certain astrophysical objects. This thesis is composed of studies that both rely on and enable this technique to study the structure of planet-forming disks and soon image the closest regions around super-massive black holes. Young stars form out of a cloud of gas and dust that, before its eventual dissipation, flattens to a disk. However the disk population is diverse and recent high-resolution images have revealed a wide variety of interesting features. To understand these observations we use detailed radiative transfer models to motivate various physical scenarios. First we identify a set of traits in the disk around V4046 Sgr that marks the coupled progression of the gas and dust distributions in the presence of at least one embedded companion. Next, we investigate how the vertical temperature structure of a disk can be spatially resolved and apply our framework to observations of the disk around HD163296. Lastly, we show how large-scale radial flows of gas may be observable and question how this phenomenon might be distinguished from other scenarios such as warps or outflows. The last chapter summarizes the APHIDS project which changes the sampling rate of data taken at the SMA so that it may be used for VLBI campaigns.
Tuesday 7 May 2019, 14:00 - Teknologiebygget, room 3.028
Professor J. P. Rozelot
Université de la Côte d'Azur, Nice, France
How big is the Sun ? A critical assessment of the diameter data over the centuries
The measurement of the solar diameter has a rich history extending well back into the past. Tackled by Greek astronomers from a geometric point of view, an estimate, although incorrect, has been first determined, not truly called into question for several centuries. A canonical value was adopted by Auwers in 1891. In spite of considerable efforts during the second half of the XXth century, involving dedicated space instruments, no consensus has been reached on this issue. However, a shrinking or an expanding shape is ultimately linked to solar activity, as gravitational or magnetic fields, which are existing mechanisms for storing energy during a solar cycle, lead to distinct perturbations in the equilibrium solar structure and changes in the diameter. We will here give a brief review of some of the most remarkable techniques used in the past, emphasizing the advent of high sensibility instruments on board satellites, such as SDO, which allows accurate determination of the shape of the Sun. Furthermore, notable features of the Near Sub-Surface Layer (NSSL), called the leptocline, can be established in relation to the solar limb variations, mainly through the shape asphericities coefficients. Recent studies encourage further in-depth investigations of the solar subsurface dynamics, observationally through SDO: we will show the latest results on such solar limb shape asphericities. It turns out that such modern measurements are one of the ways we have now for peering into the solar interior, learning empirically about flows and motions there that would otherwise only be guessed from theoretical considerations.
Friday 15 March 2019, 14:00 - Realfagbygget, room will be announced
Professor J. M. C. Plane
School of Chemistry, University of Leeds, United Kingdom
Cosmic Dust in Planetary Atmospheres (including Earth)
Cosmic dust particles are produced in the solar system from the sublimation of comets as they orbit close to the sun, and also from asteroidal collisions between Mars and Jupiter. Recent advances in interplanetary dust modelling provide much improved estimates of the fluxes of cosmic dust particles into planetary (and lunar) atmospheres throughout the solar system. Combining the dust particle size and velocity distributions with new chemical ablation models enables the injection rates of individual elements to be predicted as a function of location and time. This information is essential for understanding a variety of atmospheric impacts, including: the formation of layers of metal atoms and ions; meteoric smoke particles and ice cloud nucleation; perturbations to atmospheric gas-phase chemistry; and the effects of the surface deposition of micrometeorites and cosmic spherules.
In this seminar I will describe the results of a large study designed to determine the input rate of cosmic dust to the terrestrial atmosphere, using a self-consistent treatment of cosmic dust from the outer solar system to the Earth’s surface. An astronomical model which tracks the evolution of dust from various sources into the inner solar system was combined with a chemical ablation model to determine the rate of injection of metallic vapours into the atmosphere. Constraining these coupled models with observations of IR emission from the Zodiacal Cloud, lidar measurements of the vertical fluxes of Na and Fe in the terrestrial mesosphere, and the rate of accretion of cosmic spherules at the South Pole, indicates that about 30 tonnes of dust enters the Earth’s atmosphere each day. Having fitted the astronomical model to the terrestrial input, the same model can be used to predict the dust inputs into the atmospheres of Venus and Mars. A separate outer solar system model has also been used to determine the dust input into Titan’s atmosphere. The Chemical Ablation Model (CABMOD), which is central to quantifying planetary impacts, has recently been tested using a novel experimental system developed at Leeds: a Meteor Ablation Simulator, which measures the evaporation of metals from meteoritic particles that are flash heated to over 2800 K with a time-resolved temperature profile simulating atmospheric entry.
Examples of the impacts of meteoric ablation will then be described. For Earth: mesospheric metal layers; noctilucent cloud nucleation; freezing of polar stratospheric clouds; and deposition of bio-available Fe to the Southern Ocean. For Venus: oxidation of CO and removal of O2on meteoric smoke particles in the hot troposphere. For Mars: production of an Mg+layer which has recently been observed by the MAVEN spacecraft. And for Titan: the production of benzene in the troposphere by the cyclo-trimerization of acetylene on dust particles.
Monday 4 March 2019, 10:00 -Realfagbygget, Auditorium 2.018
Dr. Hervé Lamy
Belgian Institute for Space Aeronomy, BIRA - IASB, Brussels, Belgium
BRAMS - the BelgianRAdioMeteorStationsNetwork
BRAMS (Belgian RAdio Meteor Stations) is a Belgian network using forward scatter of radio waves off ionized meteor trails to detect and characterize meteoroids. In this talk, the BRAMS network, the BRAMS data and the current status of the algorithms to analyze the data will be presented. A comparison between radio data obtained with BRAMS and optical data obtained using CAMS and/or FRIPON cameras will also be provided. Future plans will conclude the talk, including the current status of an in-house meteor radar we are currently developing.
Wednesday 27 February 2019, 14:00 - Realfagbygget, Auditorium 2.017
Dr. Donald M. Hassler
Southwest Research Institute, Boulder, Colorado, USA
Scientific Drivers for a Solar Polar Mission
Solar and Heliospheric physics has experienced a golden age of discovery over the past 20+ years, and the launches of Parker Solar Probe and Solar Orbiter promise to add exciting new observations and insights into our understanding of the Sun-Heliosphere system. So what is next? Although these missions have, and promise to continue to, revolutionize our understanding of the Sun, the one region that is still unexplored is the solar pole…the solar pole is one of the final frontiers of solar physics. Although Solar Orbiter will achieve a latitude of ~32 degrees at the end of it’s extended mission, providing a first glimpse of this unexplored polar region, its observations will still be significantly foreshortened over much of the pole, and it will only collect imaging observations for 30 days per 168 day orbit. A dedicated, extended solar polar mission offers the opportunity to revolutionize our understanding of the relationship between the magnetic field and dynamics of the Sun’s polar region, it’s internal structure and dynamics, and the solar cycle.
This talk will discuss the various scientific drivers for a Solar Polar Mission, what scientific objectives can ONLY be addressed by a dedicated Solar Polar Mission, and what requirements do these scientific objectives place on the observational and orbital requirements of such a mission.
19 October 2018
EISCAT_3D Norway & FRISK Meeting Nr. 10
”Grand Challenge Initiative – Mesosphere Project”?
Conveners: Ingrid Mann, Jøran Moen & Kolbjørn Blix
Professor Roman Schrittwieser from Universität Innsbrück, Austria, was visiting on ERASMUS+ Teaching Mobility week of september 3rd - 9th. He gave the following lectures:
Wednesday 5th 14.15: Introduction to fusion and nuclear physics, in room TB 3.003
Thursday 6th: Probe diagnostics in plasmas in meeting room TB 3.038
Friday 7th: Probe diagnostics and own work in fusion plasmas in TB 1.022
(see right margin to download the talks)
Thursday 23 August 2018, 13:00 - Realf.bygget, B203 Dr. Philip Erickson
(Massachusetts Institute of Technology Haystack Observatory Westford, Massachusetts, USA)
Auroral Emissions Radio Explorer (AERO): Science and technical overview, and collaborations
Thursday 23 August 2018, 13:30 - Realf.bygget, B203
Dr. Andrew Kavanagh
(British Antarctic Survey, Cambridge, UK)
Radiation Belt slot-region filling events: sustained energetic precipitation into the mesosphere
Thursday 16 August 2018, 14:00-15:00, Teknologibygget: Rom 1.017
Professor Meers Oppenheim
(Boston University, USA)
Studying Meteor Plasma Physics with Massively Parallel Particle-in-Cell Simulations
Thursday, 26 April - 10:15 Teknologibygget 1.016
Professor Burkhard Wrenger
Ostwestfalen-Lippe University of Applied Sciences (OWL UAS), Germany,
Drone Based Environmental Monitoring
Tuesday 17 April 2018 - 12:00 Teknologibygget 3.028
Dr. Joan Stude
(Institute of Atmospheric Research, German Space Center, DLR, Pfaffenhofen, German)
The PMWE rocket campaign from Andøya on Friday 13 April
Wednesday 7 March 2018 - 14:00 Teknologibygget 3.028
Lindis Merete Bjoland (IFT / UiT)
Radar studies of plasma parameters in the polar cap and cusp
Monday 27. November - Tuesday 28. November
Visit from Murmansk Arctic State University, Murmansk, Russia
Monday 27 November
14:15 - 16:00 at Teknologibygget 3.028 Seminar
Computer modeling of physical processes in the near-Earth environment
Prof. Alexandr Namgaladze
Wednesday 1. November 2017 - 14:15 - 16:00 at Teknologibygget 2.017
Björn Gustavsson, UiT
EISCAT observation campaign October 2017
EISCAT_3D Kick-off Meeting at UiT Tromsø Campus https://eiscat3d.se/content/eiscat3d-opening-event________________________________________ Wednesday 30. August 2017 - 15:00 - 16:00 at Teknologibygget 2.017 Juha Vierinen, UiT - Arctic University of NorwayOngoing research projects________________________________________ Tuesday 20. June 2017 - 12.00 at Realfagsbygget A042 Asgeir Brekke, UiT - Arctic University of NorwayHistory of space research in Tromsø________________________________________ Wednesday 7. June 2017 - 15.15 at Teknologibygget 3.028Tarjei Antonsen, UiT - Arctic university of NorwayMaxidusty project update ____________________ Friday 7. April 2017 - 13.30 at Teknologibygget 2.008 Lassi Roininen
Imperial College London, UK University of Oulu, Finland Non-Gaussian priors and hyperpriors for Bayesian inversion We consider two classes of non-Gaussian priors: Cauchy difference priors and Matérn field priors with length-scaling modelled with continuous-parameter Gaussian or Cauchy hyperpriors. While the Cauchy priors promote edge-preserving inversion, the combination of Hyperprior and Matérn prior promotes both smoothness and edge-preserving properties. We apply the methodology to interpolation and X-ray tomography.
Lassi Roininen is currently a post-doctoral research associate at the Deparment of Mathematics of the Imperial College London, United Kingdom. He is also an Adjunct Professor in applied mathematics in the University of Oulu, Finland, and post-doctoral researcher at the Sodankylä Geophysical Observatory. Roininen works on a broad spectrum from the fundamental mathematical inverse problems theory to applications in near-space remote sensing and subsurface imaging. He collaborates with high-level international research groups both in academia and industry. Roininen’s research highlight is the development of the methodology of discretisation-invariant and computationally feasible priors for Bayesian inversion of function-valued unknowns. Applications include e.g. tomography (ionospheric, electrical impedance, X-ray) and radar pulse-compression coding and analysis methods. ___________________ Wednesday 8. March 2017 - 14.00 at Teknologibygget 2.018 Herve Lamy and Mathieu Barthelemy
Belgium Institute for Space Aeronomy, Brussels, BelgiumInstitut de Planetologie et d'Astrophysique de Grenoble, France Spectroscopy and Polarimetry for auroral monitoring: ATISE and !er Cru experiments. Thursday 16. March 2017 - 09.00Arne BjørkUiT Arctic University of Norway, Narvik Title to be announced _____________
Tuesday 17. Januar 2017 - 13:00 at Teknologibygget 3.028
Finnish meteorological institute, Helsinki & Sodankylä geophysical observatory, University of Oulu
Bayesian ionospheric multi-instrument 3D tomography
Wednesday 7. December 2016 - 14:15 location to be announced
University of Bergen, Department of Physics and Technology
Cold ion outflow from the polar caps: Combining satellite and radar measurementsEvery day, the Earth loses a significant amount of mass through ions escaping from thepolar ionosphere. Due to spacecraft charging effects and the very low escape energy ofions, in-situ measurements using traditional plasma instruments are typically not able todetect the cold component of the outflow. However, recent advances in instrumentationand methodology, combined with a comprehensive data set from the Cluster constellationof spacecraft, have provided far better opportunities to assess the role of the low energy ions. Results suggest that the polar cap region is the primary source of cold outflow, but enhanced outflow from the cusp and auroral zone is observed during disturbed geomagnetic conditions. Observations from the EISCAT Svalbard provide the ionospheric context for the outflow. Above the exobase, the transport of cold ions is mainly governed by the convection, and most of the outflowing ions are transported to the night-side plasma sheet. Direct loss along open field lines down-tail into the solar wind only takes place during quiet magnetospheric conditions with low or stagnant convection. We also note a puzzling north-south asymmetry in the outflow, with outflow from the northern hemisphere, persistently higher than that of the southern hemisphere. _____________
Wednesday 30. November 2016 - 14:15 - 15:00 at Teknologibygget 3.028
Solar-Terrestrial Environment Laboratory, Nagoya University, Japan
Multi-beam sodium LIDAR observations at RamfjordmoenWe installed a sodium LIDAR in March 2010, and started LIDAR observations ofneutral temperature and sodium density in the Mesosphere/Lower thermosphere (MLT) regionbetween 80 and 110 km. In October 2012, we started five-beam observations with the LIDAR:we can observe simultaneously five volumes and derive neutral wind as well.Combining other data obtained by instruments operated at the same field such asthe EISCAT radars, meteor and MF radars, a photometer, an all-sky digital camera, we have studiedgravity waves and sporadic sodium layers (SSLs). I will show these results, and also have discussionswith possible collaborations in the near future.__________
Wednesday 9. November 2016 - 14:15 - 15:00 at Teknologibygget 3.028
NeIC EISCAT 3D support project
The NeIC EISCAT_3D support (E3DS) project aids the future EISCAT_3D project in planning and tendering their required e-infrastructure. This includes the gathering of the EISCAT_3D use-cases and transforming these into a set of standard requirements for the various components of the overall EISCAT_3D computing e-infrastructure. The NeIC EISCAT_3D support project interacts with EISCAT_3D and Grid and Cloud e-infrastructure projects. This interaction is needed to match the expertise in EISCAT_3D with corresponding expertise in the existing e-infrastructure projects in the various fields. This presentation will provide an overview of the project for the space physicists who are the scientific users of the present EISCAT radar and the future EISCAT_3D.____________ Monday 24. October 2016 - 13:00 -14:00 at Teknologibygget 2.018AUD Ilkka Virtanen University of Oulu, Oulu, FinlandMulti-beam Incoherent Scatter Radar Observationsand Maxime GrandinUniversity of Oulu, Oulu, FinlandKilpisjärvi Atmospheric Imaging Receiver Array Observations of Pulsating Aurora Signatures in Cosmic Radio Noise Absorption _____________ Wednesday 12. October 2016 - 14:15 at TEKNOBYGGET 2.018AUD Jakub Vaverka Department of Physics, Umeå University, Sweden Search for meteoroid hypervelocity impacts on Earth-orbiting spacecraft There are several different techniques that are used to measure cosmic dust entering the Earth's atmosphere such as space-born dust detectors, meteor and HPLA radars, and optical methods. One complementary method could be to use electric field instruments initially designed to measure electric waves. A plasma cloud generated by a hypervelocity dust impact on a spacecraft body can be detected by the electric field instruments commonly operated on spacecraft. Since Earth-orbiting missions are generally not equipped with conventional dust detectors, the electric field instruments offer an alternative method to measure the Earth's dust environment.
Wednesday 28. September 2016 - 14:00 at TEKNOBYGGET 2.018 AUDZoltan Sternovsky Laboratory for Atmospheric & Space Physics; & Aerospace Engineering Sciences, Univ. of Colorado, Boulder, CO
In-Situ Detection and Analysis of Cosmic Dust Particles: from the Upper Atmosphere to Distant Worlds
It is in the form of dust particles that heavy elements recycle from dying stars into freshly forming planetary systems. Today, in our solar system, dust particles are still continually generated, processed, and destroyed/expelled with a range of dynamical processes governing their fate. The in-situ detection and analysis of dust particles, including their trajectories and elemental/chemical makeup, thus allows insight into the formation and currect state of the solar system, including Earth. Cosmic dust particles available for in-situ detection can be broadly sorted into four categories: interplanetary dust, interstellar dust, circum-planetary dust, and ejecta dust clouds around airless planetary objects. The Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado is one of the few institutes engaged in the development of dust detector and analyzer instruments; and is equipped with unique laboratory calibration facilities. The latter includes a 3 MV electrostaic dust accelerator that allows the study of impact processes at the hypervelocity range commonly encoutered in space. In this presentation I will review the instrument development efforts of the past decade at LASP, starting with the detection of meteoirc smoke particles in the upper atmosphere, and ending with the capabilites of the state-of-the art dust analyzer currently under development for the upcoming Europa Mission (NASA) to characterize the habitability of this distant icy world.
Thursday 18. August 2016
Sodankylä Geophysical Observatory / University of Oulu, Finland
D-region ionisation characteristics inverted from ground based measurements
|Introduction to fusion physics R Schrittwieser 201809|
|Probe Diag Basics 201809 Tromsö|
|Probe Diag Fusion Plasma 201809 Tromsö|