Orbital eccentricity and Earth's seasonal climate
John Chiang, Professor
Geography
Closed. This professor is continuing with Fall 2024 apprentices on this project; no new apprentices needed for Spring 2025.
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: One possible project is examining a regional climate where orbital eccentricity appears to play a more substantive role in the seasonal cycle; possibilities include the rainfall climates of Hawaii and New Zealand, and the seasonal cycle of the Southern Hemisphere westerlies; for this, 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. Another possible project is to undertake simulations with a simplified climate model. 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 (2 semesters at least), and there is a possibility of a paid summer position (funded by an NSF grant) to continue the work in Summer 2025 if things go well.
Hours: to be negotiated
Related website: https://pages.github.berkeley.edu/jch-chiang/webpage/DistanceEffect/
Related website: https://rdcu.be/ds9kO