Dear Mingshun,

I was about to answer to your post, but you beat me to it. You are correct that there is a discrepancy in notation with the Geider et al. (1997) paper.

Geider et al. (1997) describe the factor rho_chl, i.e. the factor that determines synthesis of chlorophyll in viable phytoplankton cells, as the ratio between achieved phytosynthesis and maximum potential photosynthesis. In Fennel and Boss (2003) in equation 10 and in Fennel et al. (2006) in equation 8, I calculate maximum potential photosynthesis as alpha x I x Chl, because the amount of pigment that can absorb photons determines maximum photosynthetic potential. I believe this is the correct implementation of the intention of the Geider model, i.e. regulating chlorophyll synthesis by the ratio of achieved-to-maximum potential photosynthesis.

Hence I would discourage the substitution you proposed. Before doing so you could explore the ramifications in a simple test case like the steady-state model in Fennel and Boss (2003).

Fennel & Boss (2003):

http://aslo.org/lo/toc/vol_48/issue_4/1521.pdfFennel et al. (2006):

http://memg.ocean.dal.ca/memg/pubs/Fenn ... GBC_06.pdfBest, Katja