Investigating the Impact of Sea Ice Thickness on Under-Ice Light Spectra and Its Consequences for Phytoplankton Communities and Carbon Export Efficiency in the Southern Ocean

This Jupyter Notebook contains the code necessary to recreate all of my figures and work for my self-study on how under-ice light spectra affects the taxonomy of phytoplankton communities and how that impacts carbon export efficiency in the Southern Ocean. This project is currently mentored by Dr. Andrew Thompson, the director of Caltech's Linde and Maxine Center for Global Environmental Sciences and Sarah Zhang, a current Caltech graduate student in the Linde and Maxine Center for Global Environmental Science.

NOTE: This project is still in progress, and thus may be updated frequently.

I plan to use the results from research to update the ECCO-Darwin Earth Systems Model.

Installation Requirements

1. Downloaded files from Soja-Wozniak Figshare, which are publicly accessible (but you need to download them yourself and insert them in your working directory). LINK TO FIGSHARE: https://figshare.com/s/abe54f20cd0165596170
2. Jupyter Notebook
3. Relevant Python Libraries, especially icepyx and argopy (see notebook)

Usage Requirements

The notebook contains different directories that are referenced — of course, you can change them if you would like to, but if you would like to have directories that work with the notebook, create the following empty directories within your working directory (wherever you host this notebook).

1. One directory titled "sojawozniak" (don't include quotes), in which you should place all the files you downloaded from the above figshare link
2. One empty directory titled "poc_outputs"
3. One empty directory titled "argo_underice_outputs"
4. One empty directory titled "peek_netcdf"

Usage Examples

This notebook was initially created in an internship at Caltech's Linde and Maxine Center for Global Environmental Science.

See the proposal that I proposed to my mentor, Dr. Andrew Thompson, here: https://docs.google.com/document/d/1OTRu5jwYZ_gxmuOqAVuG0Z2QTsgiwiNgTiicFJurzOQ/edit?usp=sharing

See images of figures from this notebook here: https://drive.google.com/drive/folders/1nP66t2jDdDY9OLX6wRbGs_ArgII7wbhY?usp=sharing

Authors + Acknowledgements

All code is original code written by Audrey Ma. Special thank you and acknowledgement to Dr. Andrew Thompson, director of Caltech's Linde and Maxine Center for Global Environmental Science, and Sarah Zhang, a current Caltech graduate student in the Linde and Maxine Center for Global Environmental Science, for mentoring this project. Another special acknowledgement goes to Dr. Brad Marston, currently the President-elect of the American Physics Society, who I spoke to after a lecture and connected me with resources that helped shape this project in its beginning stages. Additionally, like to specifically thank Dr. Soja-Wozniak, who I was in contact with and was immensely helpful in supporting my use of her files from her figshare.

I would also like to acknowledge these papers that were helpful in this project:

"Ice Loss Is Transforming the Light-Absorption Properties of Seawater"

https://physics.aps.org/articles/v18/109#:~:text=This%20disappearing%20ice%20is%20narrowing,these%20icy%20regions%20of%20Earth

Soja-Wozniak et al. 2025 "Loss of sea ice alters light spectra for aquatic photosynthesis"

https://www.nature.com/articles/s41467-025-59386-x?fromPaywallRec=false#citeas