SNSF Ambizione grant awarded to Franziska Zeuner

SNSF Ambizione grants are aimed at early-career postdoctoral researchers who wish to conduct their first independent project in Switzerland. The Swiss National Science Foundation yearly awards these projects to the most promising researchers after a competitive two-step evaluation procedure, which includes an interview in front of the evaluators.

For the 2023 call, the SNSF has selected 97 projects from a total of 435 submitted proposals. Among them, we are happy to announce that 3 researchers will conduct their Ambizione project at USI: Franziska Zeuner (Istituto ricerche solari Aldo e Cele Daccò), Martin Gjoreski (Computer Systems Institute, Faculty of Informatics), William Davis (Institute of Urban and Landscape Studies, Academy of Architecture).

Thanks to their Ambizione grant, they will be able to carry out their 4-years projects autonomously and to manage their own small research team, acquiring further project management skills. These projects thus represent an important step forward in their career.

Meet the Ambizione awardee

Franziska Zeuner (Istituto ricerche solari Aldo e Cele Daccò)

What is your project about?

My project is in the field of astrophysics and daytime astronomy with the title “En route to 3D Hanle diagnostics in stellar atmospheres: the observational perspective”. I am focusing on the Sun, which harbors a surprisingly high number of open questions. One fascinating aspect of the Sun which is fundamental to understand solar activity and therefore its impact on Earth is the solar magnetic field. Newly operational large solar telescopes allow us to study the physics of our central star in unprecedented detail. However, one aspect which is very difficult to study are magnetic fields on the Sun’s surface which are smaller than the resolution of even the largest solar telescopes. Magnetic fields can leave traces in the light that reaches us, but if they are too small, they can “hide” from detection with conventional techniques.

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GCOS-funded five-year project about sunspot data concluded

At the end of July the five-year project funded by the Global Climate Observing System (GCOS) Switzerland, which involved the Specola Solare Ticinese and the ETH-Zurich University Archives, came to an end. The aim of the project was to digitise, preserve and disseminate the data, in both analogic (drawings) and digital format, the observations carried out at the Specola from its foundation in 1957 to the present day.

All original drawings are now safely stored in the Zurich archives and the high-resolution scans can be viewed on the e-manuscripta website (https://www.e-manuscripta.ch/). The complete database, updated to the present day, can be consulted freely of charge on the Specola website (https://www.specola.ch/) and contains data on all drawings and sunspot groups (number, counting, classification, coordinates). The database is also be downloaded from the Zenodo repository (https://doi.org/10.5281/zenodo.8117331) as benefit for the scientific community of solar physics or climatology, but also for anyone interested in research on our star.

Over the next few years, the project will continue thanks to funding from the Canton of Ticino through Swisslos funds, with the aim of further expanding the data collected in the database.

The completion of the project would not have been possible without the tireless, constant and patient collaboration of all the observers who, from 1957 to the present day, have served at the Specola. In particular, the authors wish to dedicate this result to the most prominent among them, namely Sergio Cortesi (1932-2021).

The project has been carried out with the support of the Federal Office of Meteorology and Climatology MeteoSwiss, in the framework of GCOS Switzerland.

The Specola would like to thank for their indispensable cooperation the ETH-Zurich University Archives and DigiCenter, in particular by Evelyn Boesch and Christian Huber, the staff of the Solar Influences Data Analysis Center (SILSO) who developed the DigiSun software and provided invaluable advice on a regular basis, in particular Frédéric Clette and Sabrina Bechet, and the staff of the Istituto ricerche solari Aldo e Cele Daccò (IRSOL Christian Skorski and Bruno Barbieri. The Specola Solare Ticinese is supported by funding from the Canton of Ticino through Swisslos funds.

José Roberto Canivete Cuissa concludes his PhD at IRSOL

José Roberto Canivete Cuissa successfully defended his thesis work «Numerical Simulations of Magneto-Convection: From Stellar Dynamos to Small-Scale Swirling Motions» on August 31, 2023 at the Institute for Computational Science of the University of Zürich. «Roberto» as he is commonly called, is from Riviera (TI) and carried out his doctoral thesis at IRSOL in the numerical simulations group of Oskar Steiner. His main topic of research was small swirling motions in the solar atmospheres that resemble terrestrial tornadoes but different from those are connected to magnetic fields. These magnetic tornadoes have been discovered by observations of the Sun only two decades ago.

Roberto analyzed numerical simulations of the solar atmosphere and discovered that these tornadoes are pulses of torsional Alfvén waves that propagate along magnetic lines of force in the vertical direction from the solar surface to the outer solar atmosphere. Thus, they can transport mechanical energy from the solar surface to the chromosphere and the corona, where they may dissipate and turn this energy into heat. On the way to this discovery, Roberto derived a novel hydrodynamic equation for the swirling strength, a quantity similar to the vorticity but better suited as a measure for the strength of vortical motion. He also created an innovative software tool for finding vortical motions in a two-dimensional flow-field (available under https://github.com/jcanivete/swirl) and he applied it to numerical simulations of the solar and stellar atmospheres for a statistical analysis. The SWIRL code can also be used in different fields of research, such as in local climate research as it was recently done. Beyond that, Roberto carried out magnetohydrodynamic simulations of stellar magneto-convection for which he modified the well-known simulation code RAMSES, making it fit for stellar and solar applications.

His results got published in five peer-reviewed articles in «Astronomy & Astrophysics», one of the highest regarded astrophysical journal. Furthermore, Roberto also substantially contributed to a review article on vortex motions in the solar atmosphere and to a scientific article that resulted from a student project at University of Zürich on intensity interferometry, both in peer-reviewed astrophysical journals.

At IRSOL, we congratulate  Dr. José Roberto Canivete Cuissa for his splendid achievements!

From left to right, Prof. Ravit Helled (academic supervisor), Dr. José Roberto Canivete Cuissa Dr.Oskar Steiner (research co-supervisor).

USI’s first PhD in cooperation with IRSOL

On August 8, Simone Riva, a doctoral student at the Faculty of Informatics of the Università della Svizzera italiana, successfully defended his PhD thesis at USI. This is the first PhD awarded by USI within the framework of a cooperation with the Istituto ricerche solari Aldo e Cele Daccò (IRSOL). Dr. Riva developed his research under the supervision of Dr. Luca Belluzzi and Prof. Rolf Krause and will continue his studies as a postdoc within the scientific cooperation between IRSOL and USI.

Simone Riva focused his activity on the development of high-perforance-computing techniques, needed to model with unprecedented accuracy the intensity and polarization of particular lines of the solar spectrum, which encode precious information on important phenomena taking place in the chromosphere, i.e. the layer above the solar surface visible to the human eye, and on the boundary between the chromosphere and the outermost region, the corona. The modeling of these lines requires considerable computing power and had so far been performed by applying some simplifying approximations. After initial tests, the algorithms developed by Dr Riva proved to be perfectly suitable to perform applications in state-of-the-art three-dimensional models of the solar atmosphere, and revealed artefacts and inaccuracies produced by the previous simplifications.
The computational tools developed in this thesis open up unprecedented possibilities to access the wealth of information encoded in the new spectro-polarimetric observations of the solar chromosphere, carried out both from ground and from space.

“We at IRSOL are very thankful to USI for this opportunity to advise students in their research projects and open for them opportunities to space and solar research using advanced computational methods and facilities available at USI”, commented Prof. Svetlana Berdyugina, director of IRSOL, adjunct professor at the USI Faculty of Informatics and a chair of the examination committee.

From left to right, Prof. Krause, Dr. Belluzzi and Dr. Riva (photo Dr. Franziska Zeuner).