Seminars & Internal Meetings

 

Seminars are usually held on Thursdays afternoon. Contact etienne.gavazzi@uit.no if you whish to be included in the mailing list.


 

2024.02.22, 13:00 - 14:00, Forskningsparken A289 / Remotely

Speaker: Tobias Stein

Affiliation: University of Göttingen

Title: Solar Radiation Sweeping Dust through the Solar System: A peculiar asymmetry

Abstract:

When the dust particles in the cloud of dust around the Sun collide, the resulting smaller particles get blown away by the Sun's radiation. But where do they get blown away to? When analyzing this, a highly unexpected result is seen: We observe many of these particles over the Sun's ecliptic north pole, but none over its south pole. In this talk, we will try to make sense of an asymmetric Solar System, while also learning about the physics of dust and how we detect it.

 

It is also possible to join the seminar remotely.
Meeting ID: 651 2505 4729

 


 

2023.12.06, 15:00 - 16:00, Forskningsparken A289

Speaker:  Hans Pecseli

Affiliation: UiO/UiT

Title: Kinetically unstable ion velocity distributions formed via charge exchange collisions by E×B-drifts in magnetized plasmas

Abstract:
The stability of ion velocity distributions in magnetized plasmas is studied under conditions where the plasma has an E × B-drift with respect to a neutral background. Charge–exchange collisions can give rise to velocity distributions in the form of a ring or a loss-cone, being linearly unstable. Simple arguments can explain the process. Usually the distributions have distorted forms, and a stability analysis is not straightforward. Numerical simulations offer the most convenient method of a stability analysis in such cases. A particle-in-cell code that includes collisional interactions shows the formation of such velocity distributions and the instabilities associated with them. We observe the saturation of the linear instability by quasi-linear velocity space diffusion. The parameter dependence of the instability conditions is illustrated by examples. The results may be relevant for explaining some of the low-frequency oscillations observed in the lower parts of the Earth’s ionosphere (E- and F-regions), where collisions with neutrals are abundant. The results can be important for laboratory experiments as well.

 

It is also possible to join the seminar remotely. Just know that the quality won't be as good as usual as we are not able to use the microphone and the camera of the room due to a new hardware incompatible with zoom.
Meeting ID: 651 2505 4729

 


 

2023.11.23, 14:30 - 15:30, Forskningsparken A289

Speaker:  Tomotaka Tanaka

Affiliation: SOKENDAI/NIPR

Title: How effective is the mirror force for the altitude profile of electron density?

Abstract:
We will show simulation results of electron density profiles by electron precipitation in the altitudes between 70 km and 85 km. We used data of electron fluxes obtained with the ELFIN satellites and a simulation code of ionization rate developed by Katoh et al.(2023). The simulation code enables us to investigate mirror force effects. We compared the electron density profiles from the ELFIN data and the simulation code with those from EISCAT observations.

 

It is also possible to join the seminar remotely. Just know that the quality won't be as good as usual as we are not able to use the microphone and the camera of the room due to a new hardware incompatible with zoom.
Meeting ID: 651 2505 4729

 


 

2023.11.09, 14:30 - 16:00, Teknologibygget 2.018

Speaker: Hervé Dole

Affiliation: Institut d'Astrophysique Spatiale, Université Paris-Saclay, CNRS

Title: The search for galaxy protoclusters : the rise of the large scale structure in the Universe (including results from JWST and Euclid missions)

It is also possible to join the seminar remotely:
Meeting ID: 364 317 846 326 (Teams)

 


 

2023.10.26, 13:30 - 14:30, Forskningsparken A289

Speaker: Daniel Kastinen

Affiliation: IRF Swedish Institute of Space Physics

Title: Meteors and space objects research at IRF

It is also possible to join the seminar remotely:
Meeting ID: 651 2505 4729

 


 

2023.09.22, 14:00 - 15:00, Forskningsparken A289

Speaker: Peter Berthelemy

Affiliation: Department of Electronic & Electrical Engineering, University of Bath, UK

Title: Gravity Waves (and how to find them)

Abstract:
Atmospheric gravity waves are prevalent all throughout the atmosphere, with various important effects depending on the layer. But one major problem has always been, how do you extract them from the surrounding noise?

This seminar will briefly go over the basics of gravity waves and airglow, and some of the methods used to gather useable data. It will then explain the new method for the extraction of gravity waves using Aqua-AIRS satellite data, and airglow imager data, and then will compare against the older data.

 

It is also possible to join the seminar remotely:
Meeting ID: 651 2505 4729

 


 

2023.09.21, 13:00 - 14:00, Forskningsparken A289

Speaker: Sophie Maguire

Affiliation: Space Environment and Radio Engineering (SERENE) Research Group, School of Engineering, University of Birmingham, United Kingdom

Title: Evolution of large-scale structures in the high-latitude ionosphere

Abstract:
The terrestrial ionosphere is a highly variable medium that has the ability to affect the propagation of radio waves. Within the ionosphere, large-scale structures, such as polar cap patches, auroral forms, blobs and polar holes, have been observed. Small-scale irregularities associated with these large-scale structures result from instability processes which can lead to scintillation of trans-ionospheric radio signals, such as those used for Global Navigation Satellite Systems (GNSS).

In order to test the relationship between large-scale structures and scintillation, an experiment named Scintillation and Plasma Density Gradients (SGRAD) was conducted on the European Incoherent Scatter (EISCAT) radars. The experiment aimed to observe different large-scale structures under varying geomagnetic conditions and to determine which of these are related to the scintillation of GNSS signals. It has previously been demonstrated that scintillation effects are not always observed in the presence of large-scale structures (Jenner et al., 2020). Therefore, the experiment was designed to explore whether a minimum electron density gradient and/or value is required at the edge of large-scale structures for scintillation to occur. The results from the SGRAD run on the 5th of January 2023 are presented. A polar cap patch was observed exiting the polar cap and becoming a boundary blob. We present the first direct observations of multiple plasma structuring mechanisms acting simultaneously to create a blob. Additionally, the scintillation data is in the process of being analysed.

The next stage of this work involves investigating plasma structuring at multiple scale sizes. The proposed Scales of Ionospheric Plasma Structuring (SIPS) experiment is discussed.

 

It is also possible to join the seminar remotely:
Meeting ID: 651 2505 4729

 


 

2023.09.15, 13:15 - 14:15, Forskningsparken A289

Speaker: Lakshmi Narayanan Viswanathan

Affiliation: Department of Electronic & Electrical Engineering, University of Bath, UK

Title: On the relationship between PMSE power and spectral width in the VHF and UHF frequencies

Abstract:
Polar mesospheric summer echoes (PMSE) are strong radar echoes due to the variation of the refractive index caused by modification of the electron density distribution through turbulence in the presence of ice crystals under the extreme low temperatures of summer polar mesosphere. Active experiments using powerful radio waves to heat the ionosphere indicated that the charged ice crystals might play a role in generation of PMSE thereby adding further evidence that it is a dusty plasma phenomenon. In this work, we study the relationship between the peak power of the PMSE echoes and the spectral widths obtained with three EISCAT radars operating in the frequencies 223.4 MHF, 500.3 MHz and 929.6 MHz. We have fitted Gaussian curves to the PMSE spectra and obtained the peak power of the echo and corresponding spectral width. We have also considered the possibility of contribution from incoherent scattering from the free electrons by means of fitting a Lorentzian curve to the spectra. The results reveal that most intense echoes almost always contain spectral widths in the range of 5 - 8 m/s. Interestingly, wider spectral widths do not cause intense PMSE echoes in vast majority of cases and broadening due to the incoherent scattering is not a cause for the observed wider spectral widths in those cases. The pattern exists irrespective of magnetically quiet periods, particle precipitation periods and active ionospheric heating periods. We also show rare cases wherein active turbulence generates stronger PMSE echoes, which appears to be more important for UHF frequencies. We discuss these results based on present understanding of PMSE and attempt to understand the observations.

It is also possible to join the seminar remotely:
Meeting ID: 651 2505 4729

 


 

2023.06.22, 13:15 - 14:15, Forskningsparken A289

Speaker: Yasunobu Ogawa

Affiliation: National Institue of Polar Research, Tachikawa, Japan

Title: Statistical study of high energy electron precipitation based on ERG (Arase) satellite - EISCAT collaborative observation data

Abstract:
In this seminar, we report statistical results of the relationship between wave and particle data observed by the Arase satellite and ionospheric electron density data obtained with the EISCAT Tromsø radar. Their results are based on more than 150 collaborative observations (~600 hours in total) between the Arase satellite and EISCAT radar since March 2017, and summarized as follows: (1) When the amplitude of the lower-band chorus (LBC) waves is above ~18 pT, magnetospheric electrons with energies above ~160 keV undergo pitch angle scattering, and become significantly ionized at altitudes between 65-100 km. (2) The relationship between resonance energies of pitch angle scattering and electron density increases due to energetic electron precipitation suggests that pitch-angle scattering of energetic electrons by LBC waves propagating at higher latitudes (~20 deg) rather than in the magnetic equatorial plane occurs frequently.

It is also possible to join the seminar remotely:
Meeting ID: 651 2505 4729

 


 

2023.06.15, 13:15 - 14:15, Forskningsparken B284

Speaker: Lindis Merete Bjoland

Affiliation: Department of Physics and Technology, UiB

Title: Space weather with EISCAT_3D

Abstract:
Severe space weather events pose a risk to human technologies and infrastructure. To mitigate the effect of these events, it is important to understand and monitor the solar wind-magnetosphere-ionosphere interactions and dynamics. The ESA Space Weather Service Network provides a wide range of products for such monitoring of the space weather, and we are currently working on an ESA project to assess how EISCAT_3D can be utilized within this context to enhance existing space weather products and potentially develop new products. We will present preliminary results from this study where we highlight the space weather products to which we think data from EISCAT_3D potentially could contribute, and show a few examples of how we envision these products.

It is also possible to join the seminar remotely:
Meeting ID: 651 2505 4729

 


 

2023.05.26, 11:00 - 12:00, Forskningsparken B281

Speaker: Fabio Del Sordo

Affiliation: Institute of Space Sciences (ICE-CSIC), Barcelona, Spain

Title: On the possibility of observing magnetic star-planet interaction in exoplanetary systems.

Abstract:
Exoplanetary discoveries of the last 30 years provided us with a large number of diverse planetary systems. Nowadays more than 5000 exoplanets have been discovered, and none of the systems observed so far is similar to our Solar System. One of the main tasks in exoplanetary science is now to provide a deeper characterization of these new world.
In this talk I will discuss the possibility of understanding one of the most elusive features of exoplanets, that is their magnetization. This is a key ingredient for allowing life as we know it to develop on the Earth, therefore it is natural to ask whether it is common, or not, that exoplanets too are magnetized.
I will briefly introduce the basics of what we know about exoplanets, and of what we believe to be the mechanism able to sustain their magnetization, namely a dynamo.
The most direct way to prove the magnetization of an exoplanet is to observe aurora-like emission triggered by the magnetic interaction with the winds of their host star. Conversely, planets orbiting on a very short time scale, if magnetized, may also be able to influence some features connected with stellar magnetism. I will discuss the theoretical basis of both scenarios, and present the first proposed observational evidence for both cases.

It is also possible to join the seminar remotely:
Meeting ID: 682 8360 3792

 


 

2023.04.13, 14:15 - 15:00, Forskningsparken A289

Speaker: Florian Günzkofer

Affiliation: Institute for Solar-Terrestrial Physics, German Aerospace Center (DLR), Neustrelitz, Germany

Title: Coupling of ionosphere plasma and neutral atmosphere in the ionospheric dynamo region

Abstract:
The ionospheric dynamo/transition region at∼90−150 km altitude is determined by the collisionality of neutral atmosphere and ionosphere plasma. At these altitudes, the two gases undergo a transition from being highly collisional to non-collisional. Pedersen and Hall conductivities maximize in the dynamo region and their vertical profiles strongly depend on the coupling of neutral and plasma particles. Atmospheric processes in this region (e.g. tides, gravity waves, etc.) significantly impact the ionospheric variability. Combined observations of neutral atmosphere and ionosphere plasma in the transition region are essential to understand these processes and the plasma-neutral coupling. Incoherent Scatter Radars (ISR) are capable to measure basic plasma parameters across the whole dynamo region and also allow us to infer information about the neutral atmosphere under certain assumptions. We present combined measurements of atmosphere-ionosphere coupling processes in the transition region with the EISCAT ISR located in Northern Scandinavia and other instruments in the area. Such measurements can be applied to assess the ionospheric variability caused by atmospheric processes like the mixing of tidal modes or atmospheric gravity waves. The possibility to infer additional atmosphere-ionosphere parameters is demonstrated as well

It is also possible to join the seminar remotely:
Meeting ID: 651 2505 4729

 


 

2023.03.23, 13:15 - 14:00, Forskningsparken A289

Speaker: Hans Pécseli

Affiliation:
Department of Physics and Technology, Arctic University of Norway, 9037 Tromsø, Norway
Department of Physics, University of Oslo, Boks 1048 Blindern, 0316 Oslo, Norway

Title: Minute time-scale oscillations of the magnetopause

Abstract:
It is argued that a simple model based on magnetic image arguments suffices to give a convincing insight into both the basic static as well as some transient dynamic properties of the near-Earth's magnetosphere, particularly accounting for damped oscillations being excited in response to impulsive perturbations. The parameter variations of the frequency are given. Qualitative results can also be obtained for heating due to the compression of the radiation belts. The properties of this simple dynamic model for the solar wind–magnetosphere interaction are discussed and compared to observations. In spite of its simplicity, the model gives convincing results concerning the magnitudes of the near-Earth's magnetic and electric fields. The database contains ground-based results for magnetic field variation in response to shocks in the solar wind. Here, the observations also include data from the two Van Allen satellites.

It is also possible to join the seminar remotely:
Meeting ID: 651 2505 4729

 

 __________________________________________________________________________________________________________________

Seminars from 2020 and earlier are listed below ↓↓↓
 __________________________________________________________________________________________________________________

2020.10.01 13:15-14:00

Speaker: Andres Spicher (with contributions from a long list of co-authors)

Title: High latitude ionospheric density irregularities

Abstract:

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.

2020.09.24 13:15-14:00

Speaker: Torbjørn Tveito
 
Title: Low frequency planetary radar studies of the Moon
 
Abstract:
Studies of extra-terrestrial surfaces can help us investigate the conditions of the primordial solar system. Our nearest neighbour, Luna, provides an excellent target for Earth-based radio remote sensing experiments, as it's surface is not affected by the erosive processes present on Earth. Another important factor is the relatively low distance, as the reflected signal strength is proportional to $R^{-4}$. In this presentation, I briefly describe the lunar surface and it's scattering characteristics, as well as some interesting results of a long-wavelength mapping campaign. Further, I describe the usefulness of EISCAT 3D as an instrument for lunar synthetic aperture radar mapping.

 

2020.09.17 13:15-14:00

Margareta Myrvang and Johann Stamm

Title: Sopp

Abstract:

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!

2020.09.10 13:15-14:00

Markus Floer

Title: Svalbard - a hot-zone within space physics. You can/should also go there and study.

Abstract:

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.

2020.09.03 13:15-14:00 

Björn Gustavsson

Title: Dynamic aurora - how to calculate the ionospheric responses when things happen quickly (Part 2/2)

 

2020.08.27 13:15-14:00 

Björn Gustavsson

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
observations.

Friday 22 November 13:15 - Seminar room FPARK 289 - Forskningsparken

Adrien Pineau

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

 


 
 
 
5 - 9 September 2019

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 

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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

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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 

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Wednesday 1. November 2017 - 14:15 - 16:00 at Teknologibygget 2.017
Björn Gustavsson, UiT
EISCAT observation campaign October 2017

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Wednesday 27. September 2017 - 14:15 - 16:00 at Teknologibygget 2.017
Andrzej Czechowski, Space Research Institute, Polish Academy of Sciences, Warsaw, Poland 
Nanodust dynamics in the heliosphere 
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Wednesday 6. September 2017 - 14:15 - 17:00 
EISCAT_3D Kick-off Meeting at UiT Tromsø Campus 
Thursday 7. September 2017 
EISCAT_3D Kick-off Meeting at UiT Tromsø Campus and Skibotn Fieldstation
Friday 8. September 2017 - 9:00 - 13:00 
EISCAT_3D Kick-off Meeting at UiT Tromsø Campus  
https://eiscat3d.se/content/eiscat3d-opening-event
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Wednesday 30. August 2017 - 15:00 - 16:00 at Teknologibygget 2.017 
Juha Vierinen, UiT - Arctic University of Norway
Ongoing research projects
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Tuesday 20. June 2017 - 12.00 at Realfagsbygget A042 
Asgeir Brekke, UiT - Arctic University of Norway
History of space research in Tromsø
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Wednesday 7. June 2017 - 15.15 at Teknologibygget 3.028
Tarjei Antonsen, UiT - Arctic university of Norway
Maxidusty project update
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         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.
 
 
 
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Wednesday 8. March 2017 - 14.00 at Teknologibygget 2.018 
Herve Lamy and Mathieu Barthelemy
Belgium Institute for Space Aeronomy, Brussels, Belgium
Institut de Planetologie et d'Astrophysique de Grenoble, France
 
Spectroscopy and Polarimetry for auroral monitoring: ATISE and !er Cru experiments.
 
 
 
 
Thursday 16. March 2017 - 09.00
Arne Bjørk
UiT Arctic University of Norway, Narvik
 
Title to be announced
 
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Tuesday 17. Januar 2017 - 13:00 at Teknologibygget 3.028 

Johannes Norberg

Finnish meteorological institute, Helsinki & Sodankylä geophysical observatory, University of Oulu

Bayesian ionospheric multi-instrument 3D tomography 

 
In ionospheric tomography the atmospheric electron density is reconstructed from satellite-to-ground measurements. It is an ill-posed inverse problem that cannot be solved without some relatively strong additional regularising information. Especially, the vertical electron density profile is determined predominantly by the regularisation. Despite its crucial role, the regularisation is often hidden in the algorithm as a numerical procedure without physical interpretation.
 
In Bayesian methodology the regularisation is given as a prior probability distribution. The prior mean describes the expected state of the ionosphere and the prior covariance the corresponding uncertainty. Updating the prior with the ionospheric measurements results as a posterior distribution that is again given by its mean and covariance. The distributions are quantified with physical units, hence, the method provides intuitive understanding on the regularisation, as well as the uncertainty of the results. The Bayesian approach is demonstrated here in 3D with ionospheric multi-instrument measurements over Northern Europe. The measurement setup consists of Low Earth orbit and GNSS satellite receivers, ionosondes and incoherent scatter radar measurements.
 
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Wednesday 7. December 2016 - 14:15 location to be announced

Stein Haaland

University of Bergen, Department of Physics and Technology

Cold ion outflow from the polar caps: Combining satellite and radar measurements 

Every 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.
 
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Wednesday 30. November 2016 - 14:15 - 15:00 at Teknologibygget 3.028 

Satonori Nozawa

Solar-Terrestrial Environment Laboratory, Nagoya University, Japan

Multi-beam sodium LIDAR observations at Ramfjordmoen 

We 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.
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Wednesday 9. November 2016 - 14:15 - 15:00  at Teknologibygget 3.028 

John White

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.

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Monday 24. October 2016 - 13:00 -14:00 at Teknologibygget 2.018AUD 
Ilkka Virtanen
University of Oulu, Oulu, Finland
Multi-beam Incoherent Scatter Radar Observations
and 
Maxime Grandin
University of Oulu, Oulu, Finland
Kilpisjärvi Atmospheric Imaging Receiver Array Observations of Pulsating Aurora Signatures in Cosmic Radio Noise Absorption
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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.
 

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Wednesday 28. September 2016 - 14:00 at TEKNOBYGGET 2.018 AUD
Zoltan 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.

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Thursday 18. August 2016

Antti Kero 

Sodankylä Geophysical Observatory / University of Oulu, Finland 

D-region ionisation characteristics inverted from ground based measurements