Fri, 7 Jun 2002 11:28:33 -0400 (EDT)
Sukru,
(Pat I cc-ed this email to you because it might be of interest)
1. I think the issue of ``new'' versus ``regenerated'' production comes from the fact that the no3pr and nh4pr terms are called new and regenerated production in the plot outputs. It does not mean that it is defined this way in the model (see your text at the end of this email). Actually, in the code, it is called: ``NO3 production rate'' and ``NH4 production rate''.
In the log file of a gmeta, it is called:
[PEID= 39] recycled NH4 production rate
[PEID= 40] new NO3 production rate
and then on the gmeta plots, it becomes `` recycled production'' and ``new production''.
skip slanderous material
3. In a 4D model, it is hard to estimate the new and recycled production rigorously. We would have to compute the depth of the euphotic zone (x,y,t) and than compute the flux of new nutrients tru it. So, the proxis `NO3 production rate'' and ``NH4 production rate'' can be a useful indication. Do you know of papers that also plot these? I checked in Larry's papers, he only plots no3pr+nh4pr. Does Dennis do it? I checked in his thesis, he uses f=Q1/(Q1+Q2) on page 69, but this is a mixed-layer model, so this is ok. In Fasham et al, I did not see the definition, but I think they also use f=Q1/(Q1+Q2). Sukru, could you check for this? Thanks.
4. For our issue, I think your new paragraph below is almost ok, but most likely we need to use ``NO3 production rate'' instead of new production and say that it is a proxi for new production. We should I guess also use this in the figure caption. Let me know if you agree on this point number 4.
Pierre
``Uptake of the nitrate by phytoplankton is defined as a new production in the model. Basin scale structure wes showing that the New production maximum was deeper in the northern part of the basin than the southern part. This is due to the spatial variability of the euphotic zone in the basin. As a characteristics of the summer, new production values are low and does not follow the structure of the chlorophyll-a. This indicates that pytoplankton biomass was sustained mainly by regenerated production.''