Rob started class with a fifteen minute refresher on what we had accomplished by doing an in-class analog NPZ exercise. Qualitatively, the behavior of nutrients, phytoplankton, and zooplankton were reasonable over time. But, of course, the model was very simple and thus not highly useful in explaining the sample data we investigated from Narragansett Bay.

So, Jeremy led a discussion on a useful first set of equations we could use to begin to build our own NPZ model for Narragansett Bay:



Jeremy answered questions about the various variables in the equations and their affect on the overall model. He asked questions to see where student comprehension was strong and where it was going to need reinforcement.



Bruce and Brian then provided a Python-based notebook that would allow students to investigate the equations and see what the affect was of changing variable values. The equations above, when solved by a Python ODE solver, provided the following chart for the first 100 days of output:



We discussed the mechanics of the Python code and debated various ways to test for the conservation of mass since the equations were meant to be conservative in that manner.

Students were told to make notes regarding their investigations of the code so that we could continue a discussion and then build the model further with additional interative and intermediate equations.