PhyIS units in Fennel

[Virivarola]

Hi,

I have a question about the units of the initial slope of the PI curve in Fennel.
Specifically, in fennel_mod.h the text headings tell us they are [mg_C/(mg_Chl W m-2 day)]
but in the code below we find:

real(r8), allocatable :: PhyIS(:) ! 1/(Watts m-2 day)

I checked through fennel.h and the latter should be indeed the units for this parameter,
but just in case I wanted to confirm.

Thank you,
Virginia

[m.hadfield]

I agree. I noticed this a month ago and intended to report it, but never got around to it.

[Virivarola]

thanks for your answer. I checked in Geider et al. (1997) and there it makes sense to have units of [g_C/g_Chl]/[irradiance units] for 'alfa' (his table 1) since growth in the Chla equation is written in terms of C (his equation (3)). I suppose maybe PhyIS units are hanging from there..

[diudiu]

Hi, did you get the answer for the unit of PhyIS?
If the unit is mg_C/(mg_Chl W m-2 day), then based on the equation in fennel.h
cff4=fac1*K_NO3(ng)*inhNH4/(1.0_r8+cff2)*Bio(i,k,iPhyt) will have unit 'mg_C/mg_Chl', while not nondimesnional.
If the PhyIS unit is 1/(Watts m-2 day), it will make sense/

[fgrosse]

Specifically, in fennel_mod.h the text headings tell us they are [mg_C/(mg_Chl W m-2 day)]

Which version of ROMS do you use? In my fennel_mod.h (downloaded in August this year) the unit is [1/(W m-2 day)] consistently, incl. the heading.

Best,
Fabian

[wilkin]

This was fixed at revision 741 in October 2014.