With love for Solar Physics

- I am Reetika Joshi, an Indian girl coming from a small town in the foothills of Himalaya. Meet RoCS newest Postdoctoral Fellow.

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On the Opera house with a view to the Oslo fjord: Reetika Joshi, Postdoctoral Fellow at RoCS, ITA, UiO. Photo: Private

Reetika obtained her graduate degree (B.Sc.) in Physics, Chemistry, Mathematics in 2012 and postgraduate degree (M.Sc.) in Physics in 2014 from Kumaun University, Nainital, India. She completed her Ph.D. in Solar Physics in November 2021 with Professor Ramesh Chandra, from Kumaun University, Nainital, India.

What was your field of study?

- During my Ph.D. I have worked on the small scale solar eruptions, i.e., “solar jets” using the space-borne datasets from different instruments (Solar Dynamics Observatory (SDO), Interface Region Imaging Spectrograph (IRIS) etc). With these multi-wavelength studies, we have analysed the kinematics, dynamics and magnetic topology of the solar jets. Solar jets are ubiquitous, collimated miniature plasma ejections that originate from all layers of the Sun from the solar photosphere to the solar corona. I have done a part of my Ph.D. research work at the Observatories de Paris, Meudon, France under the Raman-Charpak fellowship with Drs. Brigitte Schmieder and Guillaume Aulanier. During my stay in Meudon, I worked on the magnetic causes of these solar jets and learnt the spectroscopic techniques with IRIS.

Now along with the group at RoCS, I will continue to study the solar jets and associated small scale phenomenon with combining the space-borne datasets to the ground based observations from Swedish 1 m Solar Telescope (SST) at La Palma in the Canary Islands. It will give a new dimension to understand the physics behind small scale eruptions. 

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Multi-wavelength observations (a-b) of a solar jet with a clear validation for the magnetic flux emergence model (c) Credit: Joshi et al. 2020

When did you start working at RoCS and what is your position here?

- I joined RoCS/ITA in February 2022. I will be working here as a postdoctoral researcher mainly on the solar observations from ground based Swedish 1 m Solar Telescope.

What is the main question of your study?

- I aim to probe the highly dynamic nature of the omnipresent solar jets, their properties in different spectral lines in chromosphere and transition region, and their role in the heating of the solar atmosphere. This will be done with the coordinated solar observations from the highest spatial and temporal resolution ground-based (SST) and space-borne (SDO, IRIS) telescopes. Space-borne telescopes provide the data for the outer atmosphere of the sun (chromosphere, transition region and corona), while ground-based telescopes give access to high resolution data from the lower atmosphere (photosphere and chromosphere). In this way, these coordinated observations will cover the solar atmosphere in multi-wavelength range from the photosphere to the solar corona. These jets are believed as a source for transporting a significant amount of mass and energy from the lower solar atmosphere to the upper corona and consequently contributing to heat the solar corona and accelerate the solar wind. Hence this will advance our understanding of the heliosphere and SunEarth connection.

How do you plan to answer to the main question?

- Along with the group, I will observe the solar jets and their related small scale phenomenon, i.t., surges, spicules, Ellerman bombs, ultraviolet bursts, and explosive events in the chromospheric lines with SST and will provide a physical picture for the synthetic chromospheric images for the jets. I plan to use the inversion techniques for the observed spectral profiles to compare with the theoretical experiments. The theoretical group at RoCS has a wide experience in numerical simulations. The amalgamation of the high quality observations with numerical experiments will be very useful for examining the triggering causes of the solar jets.

What brought you to Oslo? Why RoCS and Norway in general?

- I was always fascinated by the beautiful high quality observations by SST and that’s why RoCS was my first choice to join after my Ph.D. I am really excited to participate in the SST telescope (at LaPalma) observations during coordinated campaigns.

RoCS is the well known international centre for connecting the physics from solar chromosphere to the corona with the combination of high quality solar observations and theoretical modelling.

Along with that RoCS has been a part of ESA’s newly launched Solar orbiter mission and they are majorly involved in one of the remote sensing instrument SPICE onboard Solar Orbiter. In this way, RoCS is a good platform for my research career and gives me the possibility to collaborate with experts from all over the globe.

How can you describe your experience here so far?

- In one word: “Fantastic”. I came to ITA because I knew it would be the best place for me to pursue my research inclinations. The institute, research facilities, bright colleagues, everyone has contributed to my day-to-day learnings in the field of science. I will describe RoCS as the best place to pursue the research with the open scientific discussions and having the perfect work life balance for one's personal development. The presence of many “young” PhDs and Postdocs make the environment alive all the time. I am overwhelmed by the supportive nature of the computer staff and the other people, as they are always ready to solve the problems with so much efficiency.

Apart from the work place, I enjoy the natural beauty of Oslo while exploring the Norwegian culture. So far I have seen the snow face of the city and I really look forward to seeing the colorful Oslo in Spring.

What do you expect from your experience at ITA and in Norway?

- I joined RoCS/ITA as my first postdoc and I look forward to learning the new observational skills and a fundamental knowledge about the numerical codes developed by the group.

The training experience will help me to become an independent researcher with expertise in observations and modelling. The group has very close collaboration and participation with the space missions by ESA and NASA, hence I look forward to get involved and collaborate with the ongoing projects. This opportunity will give wings to my research career to fly.

Other than the work, I look forward to know the country along with the Norwegian culture, language, snow activities, and dancing auroras: the natural glow in the sky.

Young Indian woman in front of Northern lights at Sognsvann
Reetika Joshi witnessed the beautiful, bold, and blushing Northern lights on February 10, 2022 near Sognsvann lake in Oslo, Norway. - I feel so excited to witness the beautiful Aurora during my very early days in Oslo, says Joshi. Photo: Private

What do you do like to do outside working hours? Any hobbies, interests?

- I like outdoor activities, such as sports (cricket, badminton), and hiking. I play cricket and I have recently joined the Norwegian women cricket club in Oslo. This is one of the reasons which makes me so happy about Oslo, that I got a good platform for playing professional cricket for the first time. This winter, I started snowboarding along with the RoCS people and the activity is already added to my interests.

By Eyrun Thune
Published Apr. 22, 2022 11:39 AM - Last modified Apr. 22, 2022 11:55 AM