open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,

I am currently trying to simulate phytoplankton dynamics in a lake using the water quality module EUTRO (8 tracers). Simulated concentrations of phosphate, nitrate, ammonium und oxygen are agreeing with measured field data. The problem is that I can not get the phytoplankton right (simulated as microgram chl-a per litre), which is too low. I tried to work my way around the water quality manual of MASCARET in which the EUTRO equations were described, but even when I eliminate the disappearance terms, phytoplankton is decreasing a lot.

Has anyone successfully used the EUTRO model in a real world case? Or is there a way to add a minimum concentration of phytoplankton to the model? Currently (as far as I understand it), phytoplankton is calculated by the difference between growth and death multiplied by the previous phytoplankton concentration. If the growth is already hampered, phytoplankton disappears in the model domain.

Thanks a lot in advance.

Cheers,
Robert

Hello Robert

Unfortunately, you seem to be the first real user of Eutro process.
To increase the phytoplankton rate in the model, you can play directly with growth and daeth rates or indirectly by increasing the oxygen and light paraleters.
you can bring subroutines dealing with death and growth to the user fortran and then introuce different weights to each of them and see the results.

Please let me updated with your findings.
kind regards

Riadh