PhyIS units in Fennel

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Virivarola

PhyIS units in Fennel

#1 Post by Virivarola » Thu Oct 02, 2014 10:20 pm

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

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m.hadfield
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Re: PhyIS units in Fennel

#2 Post by m.hadfield » Fri Oct 03, 2014 12:49 am

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

Virivarola

Re: PhyIS units in Fennel

#3 Post by Virivarola » Mon Oct 06, 2014 5:41 pm

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
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Re: PhyIS units in Fennel

#4 Post by diudiu » Mon Nov 13, 2017 2:30 am

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
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Re: PhyIS units in Fennel

#5 Post by fgrosse » Mon Nov 13, 2017 5:09 am

Virivarola wrote: 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

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wilkin
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Re: PhyIS units in Fennel

#6 Post by wilkin » Mon Nov 13, 2017 2:17 pm

This was fixed at revision 741 in October 2014.
John Wilkin: DMCS Rutgers University
71 Dudley Rd, New Brunswick, NJ 08901-8521, USA. ph: 609-630-0559 jwilkin@rutgers.edu

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