Lindsey Oberhelmen’s Internship Journey

Lindsey Oberhelmen’s Internship Journey: from simulating the Universe to simulating our planet.

Could you tell me a bit about yourself, about your career so far, why you decided to do a PhD in Australia and an internship at ACCESS-NRI?

 

I came to Australia from the United States to do a PhD in radio astronomy at ANU, focused on understanding the Universe’s magnetic fields. Although I love astronomy, I have always felt I could use some of my skills in physics and astrophysics and do something meaningful in the great scheme of things, like addressing the intense consequences of climate change for my community in California, where wildfires and droughts affect so many people. That is why I ended up coming into this internship.

I also wanted to learn more about how to code properly and in a collaborative way. In astrophysics, you have your little code and you are the only one who is ever going to see it, so you don’t need to maintain it or make sure it is easy to navigate and understand for other people.

In addition, astrophysics is a very competitive field, and I knew that this PhD will be the end of my astrophysics journey, so I started looking for other options and I found this internship. I already had a lot of experience with simulations of the Universe, so I could imagine myself being able to transition into Earth simulations.

How does your experience as a PhD intern compare to what you initially expected?

I really wanted to get confidence in my program skills and understand how to approach a problem by writing simple functions that are testable and maintainable. I now look at computational problems very differently than when I started this internship. I wanted to know how climate simulations work, and I was shocked to learn how intricate and complex they are, because in fact, they are more complicated than the hydrodynamic simulations you use for the Universe, and on top of that, they work!

I found climate science and climate simulations fascinating. I now want to learn more about the initial conditional physical equations and the chemistry of the simulations. I feel three months is too short. I was lucky, because I already had experience with the supercomputer Gadi, so I could run simulations from day one.

What has been the most surprising aspect of your internship experience?

During my PhD, I found there is a lot of pressure on producing a scientific result, but there is hardly time to really reflect on it. But at ACCESS-NRI, you can take it slow and make sure everything is working.

This experience exceeded my expectations on learning. I expected people to be less supportive and unhappy at the level which I can I code, but there wasn’t any of that. I felt valued for the skills I do have, and I felt I have abilities that are important and valuable to this project. Everyone was super nice and patient. Probably my biggest challenge during this internship, was learning how to implement unit tests in GitHub and understanding the UM files, as I never had done it before. I felt overwhelmingly intimidated by the UM Model initially, but it was an interesting challenge.

What did you do during your internship at ACCESS-NRI?

I modified the repository of three of the most useful scripts that Martin Dix developed a long time ago. These scripts can do useful things to edit the atmosphere model we use at ACCESS-NRI (UM), except they haven’t been updated or maintained in a cohesive format that you can package.

The first of these scripts, allows you to perturb the restart file of the simulation; the second to remove or select fields’ files you don’t want for your experiment and the third, to change the valid and initial time dates for your UM file. I focused on refactoring them into a maintained form for the newest forms of Python. I made sure they worked, and that they still do what they were created for. and finally, I wrote unit tests for each of them.

The last part of my work involved writing unit tests for them and a user guide and packing the scripts up, so people can download and use them.

How would you describe the mentorship you received?

For me, as someone who wants to leave astronomy and transition to another field, it was good to hear the journey stories from people who come from an adjacent field, as I am planning to do the same in the future. Davide, Martin and Heidi were great mentors for different aspects of my work, like learning to manage project times, understanding how the simulation works, improving my writing code skills and on a whole, thinking about problems differently.

Also, I found that everyone interacts with others and values everyone. You don’t really get that feeling in the rest of the university and it is a very special, fantastic experience. I also enjoyed attending the Atmosphere working group meetings and it has been fascinating. I wish I could stay longer and continue to do more work with ACCESS-NRI. It has been a really valuable experience for me, and hopefully it has been the same for ACCESS-NRI.

What advice would you give to other PhD students considering a similar internship?

I think the main advice is to apply if you really want to get into the underbelly of the simulation and if you are interested in how you can participate in creating well written code.  Also, I would like them to understand that, even though your project seems so small, like a small salinity thing, it still has an incredible importance in the simulation.

How does the future look to you from here?

I have two more years of my PhD, so I will go back to Stromlo and to radio astronomy. I will be looking at data that is going to be used to check the physics of our understanding of magnetic fields. Magnetic fields are incredibly important to know how we formed as a Universe and how we exist, so it is important to understand them. We need to know how good the data we have is, and what are the errors on it.

A huge part of my work is working on pipelines to process the data and how they can be improved. We currently don’t do unit testing, but astronomy’s data is changing, becoming more open, as now it will be used multiple times by multiple people. I am excited to use the skills I got at ACCESS-NRI to write better code for that project and apply everything I learned during the internship.