Primary research fields
Solar and stellar atmospheres with focus on creating realistic numerical simulations to solve one of the greatest mysteries in Astronomy: The coronal heating problem. I develop high-fidelity numerical simulations of the solar atmosphere, with the goal of reproducing observed solar phenomena as accurately as possible. The Sun presents us with phenomena that remain poorly understood even with state-of-the-art observational data — detailed simulations are often the only tool capable of bridging the gap between what we observe and what we can explain.
Currrent main positions and funding
- Professor and one of PIs of the Rosseland Centre for Solar Physics (RoCS, since 2017), a center of excellence funded by the Research Council of Norway
- Responsible for software development
- Responsible for work environment and young researcher career development
- Part of refining the Master degree programme at ITA
Responsible for career development at ITA
- Chair of the Coronal Loops Steering Committee
- Member of the ISSI working group: Next-Generation Solar Flare Modelling: Bridging the multi-dimensional gap
- Member of the NASA ISWAT action group on "Origins of the Spectral Irradiance and its Intermediate Timescale Variability"
Academic interests
The solar atmosphere is one of the most fascinating and demanding problems in modern physics. Processes spanning many orders of magnitude in scale are all coupled together, and understanding any one of them in isolation is rarely sufficient.
At small scales, the interactions between individual particles and radiation turn out to matter well beyond their immediate context. In the chromosphere, the balance between neutral and ionised gas shapes how the plasma responds to the magnetic and electric fields threading through it, with consequences visible at much larger scales. Higher up, in the corona, energy is stored, transported and released in ways that push our physical descriptions to their limits. Some of the most fundamental questions in plasma physics remain wide open here, and the answers have implications far beyond our own Sun.
Bringing these processes together into a consistent physical picture is the central goal of my research, and it is a genuinely exciting challenge. It requires developing simulation tools capable of handling transitions between entirely different physical regimes, from the fluid-like behaviour of large-scale plasma flows all the way down to the motion of individual particles where that description breaks down. The range of problems this touches is broad: how magnetic structures form and rise through the solar interior, how energy finds its way into the outer atmosphere, and what physics governs its eventual explosive release. To tackle these questions, we develop and run large-scale simulations on some of the most powerful supercomputing facilities available, in Norway, across Europe, and in the United States.
Current research projects
How the Sun builds its magnetic structures
The Sun produces active regions in organised belts on either side of the solar equator, with a preferred orientation that magnetic dynamo theory can account for. Less well understood is how the magnetic concentrations responsible for these regions travel from their origin to the solar surface.
To get there, they must pass through the convection zone — a deep, turbulent layer where plasma is constantly rising and sinking. How the magnetic structures survives the journey through the convection zone is still an open question. Large-scale simulations of the solar convection zone are working to shed light on some of these unexplained effects.
Energy transport to the solar corona
The outer solar atmosphere is much hotter than the surface beneath it — a long-standing puzzle, since without a continuous energy input it would rapidly cool down. The convective motions at the solar surface carry far more than enough energy to maintain these temperatures, but how that energy is transported upward and released in the corona is not well understood.
One candidate mechanism involves coupled magnetic and fluid waves. The behaviour of these waves is analytically tractable only in highly idealised cases, well removed from the conditions in a realistic solar atmosphere. Rather than simplifying the problem to fit existing theory, we have developed a method to identify which wave types are present in our simulations and track how they evolve as they propagate through the atmosphere.
This will allow us to design targeted observational campaigns to test our simulations and build a clearer picture of how wave-based energy transport operates in practice.
Magnetic reconnection and the transition from fluid to particle descriptions
Magnetic reconnection is a process in the solar atmosphere where field lines break and reform into a new configuration, releasing energy in the process. The rate at which this happens, how energy is converted, and the resulting field structure all depend sensitively on the physics at very small scales — small enough that the individual motions of electrons and protons become relevant.
Conventional models treat these particles as a single fluid, or sometimes two separate fluids, but these descriptions break down at the scales where reconnection is most active. Moving to a full particle description at those scales, while maintaining a fluid description elsewhere, is a significant modelling challenge.
We have developed a simulation tool that handles this transition within a single running simulation. The next step is to use it to study how particle-scale physics influences the reconnection process itself.
Particle acceleration during magnetic reconnection
During reconnection, a significant fraction of the released energy goes into accelerating electrons and protons to relativistic speeds. How this energy is distributed among particles, and why it varies between flares, is not well understood. X-ray observations of solar flares give us some constraints, but the reasons behind the flare-to-flare variation, and what determines how much of the total energy ends up in accelerated particles, remain open questions.
We have developed a tool that extracts particle energy distributions directly from our simulations, making it possible to compare simulation output with X-ray observations in a more direct way than was previously possible.
Young researcher development and carreer building
I have for a long time been deeply invested in the work environment of young researchers and in creating competitive, sustainable research careers. This has led me to work not only with traditional supervision, but also with the broader skills that underpin effective research practice—such as structured project development and research management.
A central part of my work is supporting young scientists in planning, executing, and completing complex research projects. I focus on helping early-career researchers build clear project roadmaps, define realistic milestones, manage risk, and coordinate collaborations, so that their projects are both ambitious and viable. In parallel, I aim to create an environment where they are intellectually challenged, personally supported, and able to see a transparent path for their own development.
To meet these challenges, I have developed specific expertise in time management, motivation theory, resilience, long‑term knowledge retention, and research project management—areas that are rarely addressed systematically in typical research leadership roles. This knowledge is used not only to strengthen individual careers and improve project delivery, but also to foster a healthier, more collaborative and strategically aligned work culture across the entire institute.
Higher education and employment history
- Professor, Institute of Theoretical Astrophysics, UiO, 2018-
- Assistant Professor, Institute of Theoretical Astrophysics, UiO, 2007-2018
- Visiting scientist, Bay Area research institute, SF, USA, 2019
- Visiting scientist, High Altitude Observatory, Boulder, CO, USA, 2005
- Post-doc, Institute of theoretical astrophysics, UiO, 2005-2007