We work among extraordinary people doing extraordinary things; get to know some of them by reading these quick-fire interviews.
Name: Lilli Freischem
Job title: DPhil student, Atmospheric, Oceanic and Planetary Physics
What are you currently working on?
My DPhil focuses on understanding how well climate models represent clouds, and how this can be improved. Clouds are one of the biggest sources of uncertainty in climate projections. They have a huge influence on global temperatures and weather patterns, and if we want to predict exactly how the climate will change as greenhouse gas concentrations rise, we need to know how clouds will respond.
To tackle this, I train machine learning models on satellite observations so that they learn what clouds look like in the real world, and then use them to assess clouds simulated by high-resolution climate models. This gives us a more objective way of evaluating how realistic different climate models are. Clouds are incredibly complex: they come in all shapes and sizes, vary across the globe, and evolve over time, so comparing them is far from straightforward. A big part of my work is developing tools that can capture this complexity and help identify where models perform well and where they need improvement.
Alongside my DPhil, I also work on a range of machine learning for Earth observation projects. Most recently, with the Earth Systems Lab, I have been working on reconstructing the three-dimensional structure of clouds and tropical cyclones from satellite images. The aim is to better understand these systems and, ultimately, to improve cyclone forecasting and early warning systems.
Describe a typical day
I row for OUBC, the team that competes in the Boat Race, which means that my typical day starts early in the morning either in the gym or in Wallingford with a nice sunrise row. I usually arrive at the department between 9 and 10am, and head straight upstairs to grab a coffee and have my second breakfast before I start working in my plant-filled office. After quickly checking emails and my agenda for the day, I connect to an HPC server to analyse the high-resolution climate simulation outputs that I am working with. I spend most of my time training machine learning models and analysing cloud and climate datasets using Python. Most mornings, I also have a meeting with my supervisors or research group where we update each other on recent work or discuss interesting papers. Just after noon, everyone from my research group meets up and heads over to Reuben college for a nice social lunch. As all my work is computer-based, I make sure to head up to the roof terrace for coffee breaks throughout the afternoon to get some fresh air and sunshine. In the evening, I usually head back to the gym for another training session before I get to switch off and relax.
What got you into physics?
I have always loved maths and science, and I studied computer science for my undergraduate degree with the goal of using my computational skills to contribute to scientific research. That goal became much clearer when I took a module on global climate change and learned that physics is the foundation of weather and climate research. It helps us understand the processes in the atmosphere and ocean, how they interact, and how they will change as greenhouse gas emissions continue to rise. I knew then that I wanted to be part of the community of scientists working to tackle and better understand this fascinating scientific problem.
If you had an entire day at your disposal (not at work/studying), what would be your ideal way to spend it?
I would love to spend my free day outdoors, on a nice long bike ride. There’s lots of great cycling routes around Oxfordshire, a recent favourite was a cycle through the Cotswolds: we started with a short train ride to Moreton-in-Marsh and then cycled through the picturesque villages and countryside, stopping at a café for a nice piece of cake and a coffee, before finishing the rest of our loop. In the evening, I would meet up with friends and head to the Medley for a nice pizza dinner outdoors. As you can tell, my ideal day is sunny and warm enough to enjoy being outside all day!
What is your favourite place in Oxford?
This one’s easy: Peloton café on Cowley Road. It’s a great place for a relaxed afternoon work session, and a stop at Peloton for donuts on a Thursday morning has become one of my most loved traditions in the rowing team. And most importantly, there are lots of adorable dogs who frequently visit the café and love being cuddled!
Plan B: what would you be if you weren’t doing the job you are currently doing?
If I weren’t doing research, I think I’d love to work in sport. I’ve always loved being active and spending time outdoors, especially in the mountains. Sport has been such an important part of my life, whether through rowing, cycling, or the mountaineering club I was part of during my undergrad. I’ve also become more and more passionate about encouraging young people, especially girls, to get involved in sport. It builds confidence, resilience, and a real sense of community. Being able to help others discover that would be incredibly rewarding.