[A-OS20] Chemical and Biological Oceanography

[AOS20-06] pyTMM: Global ocean biogeochemical modeling in Python with the Transport Matrix Method

*Samar Khatiwala¹ (1.Waseda University)

Marine biogeochemical models are important tools in the quest to understand the cycling of chemical and biological tracers such as nutrients, carbon and oxygen, as well as key components of the Earth System Models used to project the impact of CO₂ emissions on climate. Historically, given the need for speed, global scale modeling has been performed in compiled languages like Fortran. However, as high level scripting languages such as Python and Julia gain popularity, the need for models and tools accessible from them has become imperative. In this presentation I will introduce pyTMM, a Python interface to a redesigned version of the Transport Matrix Method (TMM) software, a computationally efficient numerical scheme for “offline” simulation of marine geochemical and biogeochemical tracers. The TMM provides a convenient framework for developing and testing new biogeochemical parameterizations, as well as running existing models such as BLING and PISCES driven by circulations derived from state-of-the-art physical models. pyTMM exposes all of the TMM library's functionality in Python, including transparent parallelization, allowing users to not only interactively use models written in compiled languages, but also develop complex models in pure Python with performance approaching compiled code. The various features of the TMM library and pyTMM will be described and illustrated through examples, including a full-fledged biogeochemical model written entirely in Python.