Welcome

I am a Research Associate in Applied Mathematics at CU Boulder, where I primarily work with Ian Grooms, and a member of the Ocean Transport and Eddy Energy Climate Process Team. I obtained my PhD in Atmospheric & Oceanic Sciences from Princeton University, where I was advised by Stephen Griffies. Prior to attending Princeton University, I obtained a BSc in Mathematical Physics from the University of Alberta where I worked with Bruce Sutherland.

Research

Climate models simulate the fluid dynamics of the atmosphere and ocean on a grid, with the ocean component having grid cells with dimensions of 25-100 km. However, even with grid cells as small as 25 km, ocean models cannot fully resolve ocean geostrophic turbulence, which is analogous to ‘weather’ in the atmosphere. This turbulence plays a vital role in accurately simulating both the broader ocean structure and the exchange of heat and carbon between the atmosphere and ocean—crucial for long-term climate projections. My research addresses this challenge in two ways. First, I develop theory for ocean turbulence that can explain observations from satellites and high-resolution numerical models. Second, I try to leverage our theoretical understanding of turbulence to improve climate models by explicitly incorporating the impact of the unresolved turbulence into the models. Through these approaches, my goal is to enhance the fidelity of climate models, thereby contributing to more robust and accurate climate projections.

For an overview of my research, visit this link. Animated visualizations of the turbulent systems I study can be found here. If you have any questions or would like to contact me, feel free to reach out at Houssam.Yassin@colorado.edu.

The above video shows the vorticity (a measure of spin) from a simulation of two-dimensional turbulence using the python pyqg pseudo-spectral model. Red is positive vorticity (counterclockwise spin) whereas blue is negative vorticity (clockwise spin).