A role for orbital eccentricity in Earth's seasonal climate
John Chiang, Professor
Geography
Applications for Spring 2024 are closed for this project.
Climate science textbooks attribute the seasonal cycle of climate to Earth's axial tilt, and assumes that the influence of Earth's orbital eccentricity is negligible. However, a recent study that my colleagues and I published in Nature (Chiang et al. 2022) challenges this assumption by showing that orbital eccentricity plays a substantial role in the seasonal cycle of the eastern equatorial Pacific (the Pacific 'cold tongue').
The implication is that there may be other regional climates on Earth where orbital eccentricity also plays a substantial role in its seasonal climate, and the goal of this project is to explore this hypothesis. You can read more about the project on my website (link #1 below), and I've also recently published a position paper which outlines the hypothesis in greater detail (link #2 below).
Role: I have a set of climate model simulations varying earth's orbital eccentricity and the timing of perihelion (i.e. date of closest approach to the Sun) that can be explored to look at this question. Projects I have in mind include separating the relative roles of Earth's axial tilt and orbital eccentricity on the seasonal cycle of the tropical oceans; or examining the rainfall climates of regions where orbital eccentricity appears to play a more substantive role in the seasonal cycle. The specific problem and tasks will be worked out between the student and faculty mentor, but it will involve analysis of climate model output.
Qualifications: I'm looking for a student with a good background in physics, preferably with knowledge of atmospheric/climate physics and dynamics. They should also have background in data science/statistics, with experience using MATLAB or Python for numerical computations and analysis of large datasets.
I'm also looking for a longer-term engagement, and there is a possibility of a paid summer position (funded by an NSF grant) to continue the work through this coming summer if things go well. For this reason, seniors graduating this semester cannot be considered.
Hours: to be negotiated
Related website: https://pages.github.berkeley.edu/jch-chiang/webpage/DistanceEffect/
Related website: https://rdcu.be/ds9kO