Flexible-composition biogeochemical model results

Investigators	Mathieu Mongin, David M. Nelson, Philippe Pondaven, Mark A. Brzezinski, Paul Treguer
Co-Investigators	none
SMP Project	Si cycling and Si control of new production and organic carbon export in the Southern Ocean and the Sargasso Sea: A JGOFS synthesis
Product	Flexible-composition biogeochemical model results for the western Sargasso Sea (BATS)
Description	A flexible composition biogeochemical model (see the related KERFIX simulation for an overview and schematics of a similar model with Fe cycling.) was applied to the BATS site. The model includes two phytoplankton groups, diatoms and nonsiliceous forms. Uptake of NO3- by phytoplankton is light-dependent, but NH4+ and Si(OH)4 uptake are not and can therefore continue through the night. The model tracks the resulting C/N ratios of both groups and Si/N ratio of diatoms, and permits uptake of C, N and Si to proceed independently when those ratios are close to those of nutrient-replete phytoplankton. When they indicate a deficiency in cellular C, N or Si, uptake of the non-limiting elements is controlled by the content of the limiting element in accordance with the cell-quota formulation of Droop (1974). The model thus identifies the growth-limiting element and quantifies the degree of limitation from the elemental composition of the phytoplankton. A model simulation was run in the western Sargasso Sea (31N, 64W) with results presented for a 5 year period begining in 1991. Results are presented as noon (local time) values on 80 levels from the surface to 400m in 5m increments. Results include the following physical and biogeochemical variables: 'temp' - temperature (degree_Celsius) 'salt' - salinity (fixed at a constant 36.6 PSU) 'PUR' - photosynthetically useable radiation (uEin/m2/s) 'PAR' - photosynthetically available radiation (uEin/m2/s) 'NH4' - ammonium (mmol N/m3) 'NO3' - nitrate (mmol N/m3) 'SILICATE' - silicate (mmol Si/m3) 'diat_C' - diatom carbon biomass (mmol C/m3) 'pico_C' - picoplankton carbon biomass (mmol C/m3) 'diat_Si' - diatom silica biomass (mmol Si/m3) 'diat_chla' - diatom chlorophyll concentration (mg Chla/m3) 'pico_chla' - picoplankton chlorophyll concentration (mg Chla/m3) 'total_chla' - total chlorophyll concentration (mg Chla/m3) 'zoolg' - macrozooplankton (mmol C/m3) 'zoosm' - microzooplankton (mmol C/m3) 'DOM' - labile dissolved organic matter (mmol C/m3) 'DZO' - semi-labile dissolved organic matter (mmol C/m3) 'detsm_C' - small detritus carbon (mmol C/m3) 'detlg_C' - large detritus carbon (mmol C/m3) 'detsm_Si' - small detritus silica (mmol Si/m3) 'detlg_Si' - large detritus silica (mmol Si/m3) 'bacteria' - bacteria (mmol C/m3) Elemental ratios in organic matter: 'pico_CN' - picoplankton C:N ratio (mol C/mol N) 'diat_CN' - diatom C:N ratio (mol C/mol N) 'diat_SiN' - diatom Si:N ratio (mol Si/mol N) 'detsm_CN' - small detritus C:N ratio (mol C/mol N) 'detlg_CN' - large detritus C:N ratio (mol C/mol N) 'DOM_CN' - labile dissolved organic matter C:N ratio (mol C/mol N) 'DZO_CN' - semi-labile dissolved organic matter C:N ratio (mol C/mol N) Integrated daily fluxes and flows: 'intno3nan' - uptake of NO3 by picoplankton (mmol N/m3/d) 'intno3phy' - uptake of NO3 by diatoms (mmol N/m3/d) 'intnh4phy' - uptake of NH4 by diatoms (mmol N/m3/d) 'intnh4nan' - uptake of NH4 by picoplankton (mmol N/m3/d) 'intnh4bac' - uptake of NH4 by bacteria (mmol N/m3/d) 'intdicnan' - photosynthesis by picoplankton (mmol C/m3/d) 'intdicphy' - photosynthesis by diatoms (mmol C/m3/d) 'intsildia' - uptake of silicate by diatoms (mmol Si/m3/d) 'intdphsil' - small siliceous detritus dissolution (mmol Si/m3/d) 'intplasil' - fecal pellets(large detritus) dissolution (mmol Si/m3/d) 'intdiasil' - live diatoms siliceous dissolution (mmol Si/m3/d) 'intnanzos' - microzooplankton grazing on picoplankton (mmol C/m3/d) 'intzoszol' - macrozooplankton grazing on microzooplankton (mmol C/m3/d) 'intphyzol' - macrozooplankton grazing on diatoms (mmol C/m3/d) 'intbaczos' - microzooplankton grazing on bacteria (mmol C/m3/d) 'intdvszos' - microzooplankton grazing on small detritus (mmol C/m3/d) 'intgrazol' - total nitrogen grazed by macrozooplankton (mmol N/m3/d) 'intgrazos' - total nitrogen grazed by microzooplankton (mmol N/m3/d) 'intbacgro' - bacterial growth nitrogen (mmol N/m3/d) 'intbacnh4' - NH4 excretion by bacteria (mmol N/m3/d) 'intzolnh4' - NH4 excretion by macrozooplankton (mmol N/m3/d) 'intzosnh4' - NH4 excretion by microzooplankton (mmol N/m3/d) 'intnandvs' - picoplankton mortality to small detritus (mmol C/m3/d) 'intphydvs' - diatom mortality to small detritus (mmol C/m3/d) 'intzoldsm' - macrozooplankton mortality to detritus (mmol C/m3/d) 'intzoldic2' - macrozooplankton mortality (mmol C/m3/d) 'intzosdvs' - microzooplankton mortality to detritus (mmol C/m3/d) 'intzosdic2' - microzooplankton mortality (mmol C/m3/d) 'intbacmor' - bacterial mortality (mmol C/m3/d) 'intdvsdoc' - small detritus breakdown to dissolved organic carbon (mmol C/m3/d) 'intdvsdon' - small detritus breakdown to dissolved organic nitrogen (mmol N/m3/d) 'intdladoc' - large detritus breakdown to dissolved organic carbon (mmol C m-3 d-1) 'intdladon' - large detritus breakdown to dissolved organic nitrogen (N m-3 d-1) 'intzolplan' - macrozooplankton fecal pellets in nitrogen (mmol N/m3/d) 'intzolplac' - macrozooplankton fecal pellets in carbon (mmol C/m3/d) 'intzospsmn' - microzooplankton fecal pellets in nitrogen (mmol N/m3/d) 'intzospsmc' - microzooplankton fecal pellets in carbon (mmol C/m3/d) 'intnandoc' - picoplankton exudation in carbon (mmol C/m3/d) 'intnandon' - picoplankton exudation in nitrogen (mmol N/m3/d) 'intphydoc' - diatom exudation in carbon (mmol C/m3/d) 'intphydon' - diatom exudation in nitrogen (mmol N/m3/d) 'intzoldom' - macrozooplankton exudation in carbon (mmol C/m3/d) 'intzosdom' - microzooplankton exudation in carbon (mmol C/m3/d) 'intnh4no3' - nitrification (mmol N/m3/d) 'intnanexc' - picoplankton active excretion (mmol C/m3/d) 'intphyexc' - diatom active excretion (mmol C/m3/d) 'intdzodom' - flux of semi-labile organic matter to labile organic matter (mmol C/m3/d) 'intzoldic' - macrozooplankton respiration (mmol C/m3/d) 'intzosdic' - microzooplankton respiration (mmol C/m3/d) 'intbacdic' - bacterial respiration (mmol C/m3/d) 'intexpdvc' - small detritus carbon export at 100 m (mmol C/m2/d) 'intexpsmc' - large detritus carbon export at 100m (mmol C/m2/d) 'intexpdvn' - small detritus nitrogen export at 100 m (mmol N/m2/d) 'intexpsmn' - large detritus nitrogen export at 100m (mmol N/m2/d)
Submitted	April 2005
e-Citation	Mongin, M., D.M. Nelson and P. Pondaven.; U.S. JGOFS Synthesis & Modeling Project - Data. U.S. JGOFS. iPub: June 2005. 'date you accessed the data' http://usjgofs.whoi.edu/las/servlets/datasets
References	Mongin, M., D.M. Nelson, P. Pondaven, M.A. Brzezinski and P. Treguer. 2003. Simulation of upper-ocean biogeochemistry with a flexible-composition phytoplankton model: C, N and Si cycling in the western Sargasso Sea. Deep-Sea Research I 50:1445-1480.
Contact	Mathieu Mongin Institut Universitaire EuropC)en de la Mer - UMR CNRS 6539 Technopole Brest-Iroise Place Nicolas Copernic F-29280 Plouzané, France tel: 541-737-21-86 email: mongin@univ-brest.fr

Investigators

Mathieu Mongin, David M. Nelson, Philippe Pondaven, Mark A. Brzezinski, Paul Treguer

Co-Investigators

none

SMP Project

Si cycling and Si control of new production and organic carbon export in the Southern Ocean and the Sargasso Sea: A JGOFS synthesis

Product

Flexible-composition biogeochemical model results for the western Sargasso Sea (BATS)

Description

A flexible composition biogeochemical model (see the related KERFIX simulation for an overview and schematics of a similar model with Fe cycling.) was applied to the BATS site. The model includes two phytoplankton groups, diatoms and nonsiliceous forms. Uptake of NO3- by phytoplankton is light-dependent, but NH4+ and Si(OH)4 uptake are not and can therefore continue through the night. The model tracks the resulting C/N ratios of both groups and Si/N ratio of diatoms, and permits uptake of C, N and Si to proceed independently when those ratios are close to those of nutrient-replete phytoplankton. When they indicate a deficiency in cellular C, N or Si, uptake of the non-limiting elements is controlled by the content of the limiting element in accordance with the cell-quota formulation of Droop (1974). The model thus identifies the growth-limiting element and quantifies the degree of limitation from the elemental composition of the phytoplankton.

A model simulation was run in the western Sargasso Sea (31N, 64W) with results presented for a 5 year period begining in 1991. Results are presented as noon (local time) values on 80 levels from the surface to 400m in 5m increments.

Results include the following physical and biogeochemical variables:

'temp' - temperature (degree_Celsius)
'salt' - salinity (fixed at a constant 36.6 PSU)
'PUR' - photosynthetically useable radiation (uEin/m2/s)
'PAR' - photosynthetically available radiation (uEin/m2/s)
'NH4' - ammonium (mmol N/m3)
'NO3' - nitrate (mmol N/m3)
'SILICATE' - silicate (mmol Si/m3)
'diat_C' - diatom carbon biomass (mmol C/m3)
'pico_C' - picoplankton carbon biomass (mmol C/m3)
'diat_Si' - diatom silica biomass (mmol Si/m3)
'diat_chla' - diatom chlorophyll concentration (mg Chla/m3)
'pico_chla' - picoplankton chlorophyll concentration (mg Chla/m3)
'total_chla' - total chlorophyll concentration (mg Chla/m3)
'zoolg' - macrozooplankton (mmol C/m3)
'zoosm' - microzooplankton (mmol C/m3)
'DOM' - labile dissolved organic matter (mmol C/m3)
'DZO' - semi-labile dissolved organic matter (mmol C/m3)
'detsm_C' - small detritus carbon (mmol C/m3)
'detlg_C' - large detritus carbon (mmol C/m3)
'detsm_Si' - small detritus silica (mmol Si/m3)
'detlg_Si' - large detritus silica (mmol Si/m3)
'bacteria' - bacteria (mmol C/m3)

Elemental ratios in organic matter:

'pico_CN' - picoplankton C:N ratio (mol C/mol N)
'diat_CN' - diatom C:N ratio (mol C/mol N)
'diat_SiN' - diatom Si:N ratio (mol Si/mol N)
'detsm_CN' - small detritus C:N ratio (mol C/mol N)
'detlg_CN' - large detritus C:N ratio (mol C/mol N)
'DOM_CN' - labile dissolved organic matter C:N ratio (mol C/mol N)
'DZO_CN' - semi-labile dissolved organic matter C:N ratio (mol C/mol N)

Integrated daily fluxes and flows:

'intno3nan' - uptake of NO3 by picoplankton (mmol N/m3/d)
'intno3phy' - uptake of NO3 by diatoms (mmol N/m3/d)
'intnh4phy' - uptake of NH4 by diatoms (mmol N/m3/d)
'intnh4nan' - uptake of NH4 by picoplankton (mmol N/m3/d)
'intnh4bac' - uptake of NH4 by bacteria (mmol N/m3/d)
'intdicnan' - photosynthesis by picoplankton (mmol C/m3/d)
'intdicphy' - photosynthesis by diatoms (mmol C/m3/d)
'intsildia' - uptake of silicate by diatoms (mmol Si/m3/d)
'intdphsil' - small siliceous detritus dissolution (mmol Si/m3/d)
'intplasil' - fecal pellets(large detritus) dissolution (mmol Si/m3/d)
'intdiasil' - live diatoms siliceous dissolution (mmol Si/m3/d)
'intnanzos' - microzooplankton grazing on picoplankton (mmol C/m3/d)
'intzoszol' - macrozooplankton grazing on microzooplankton (mmol C/m3/d)
'intphyzol' - macrozooplankton grazing on diatoms (mmol C/m3/d)
'intbaczos' - microzooplankton grazing on bacteria (mmol C/m3/d)
'intdvszos' - microzooplankton grazing on small detritus (mmol C/m3/d)
'intgrazol' - total nitrogen grazed by macrozooplankton (mmol N/m3/d)
'intgrazos' - total nitrogen grazed by microzooplankton (mmol N/m3/d)
'intbacgro' - bacterial growth nitrogen (mmol N/m3/d)
'intbacnh4' - NH4 excretion by bacteria (mmol N/m3/d)
'intzolnh4' - NH4 excretion by macrozooplankton (mmol N/m3/d)
'intzosnh4' - NH4 excretion by microzooplankton (mmol N/m3/d)
'intnandvs' - picoplankton mortality to small detritus (mmol C/m3/d)
'intphydvs' - diatom mortality to small detritus (mmol C/m3/d)
'intzoldsm' - macrozooplankton mortality to detritus (mmol C/m3/d)
'intzoldic2' - macrozooplankton mortality (mmol C/m3/d)
'intzosdvs' - microzooplankton mortality to detritus (mmol C/m3/d)
'intzosdic2' - microzooplankton mortality (mmol C/m3/d)
'intbacmor' - bacterial mortality (mmol C/m3/d)
'intdvsdoc' - small detritus breakdown to dissolved organic carbon (mmol C/m3/d)
'intdvsdon' - small detritus breakdown to dissolved organic nitrogen (mmol N/m3/d)
'intdladoc' - large detritus breakdown to dissolved organic carbon (mmol C m-3 d-1)
'intdladon' - large detritus breakdown to dissolved organic nitrogen (N m-3 d-1)
'intzolplan' - macrozooplankton fecal pellets in nitrogen (mmol N/m3/d)
'intzolplac' - macrozooplankton fecal pellets in carbon (mmol C/m3/d)
'intzospsmn' - microzooplankton fecal pellets in nitrogen (mmol N/m3/d)
'intzospsmc' - microzooplankton fecal pellets in carbon (mmol C/m3/d)
'intnandoc' - picoplankton exudation in carbon (mmol C/m3/d)
'intnandon' - picoplankton exudation in nitrogen (mmol N/m3/d)
'intphydoc' - diatom exudation in carbon (mmol C/m3/d)
'intphydon' - diatom exudation in nitrogen (mmol N/m3/d)
'intzoldom' - macrozooplankton exudation in carbon (mmol C/m3/d)
'intzosdom' - microzooplankton exudation in carbon (mmol C/m3/d)
'intnh4no3' - nitrification (mmol N/m3/d)
'intnanexc' - picoplankton active excretion (mmol C/m3/d)
'intphyexc' - diatom active excretion (mmol C/m3/d)
'intdzodom' - flux of semi-labile organic matter to labile organic matter (mmol C/m3/d)
'intzoldic' - macrozooplankton respiration (mmol C/m3/d)
'intzosdic' - microzooplankton respiration (mmol C/m3/d)
'intbacdic' - bacterial respiration (mmol C/m3/d)
'intexpdvc' - small detritus carbon export at 100 m (mmol C/m2/d)
'intexpsmc' - large detritus carbon export at 100m (mmol C/m2/d)
'intexpdvn' - small detritus nitrogen export at 100 m (mmol N/m2/d)
'intexpsmn' - large detritus nitrogen export at 100m (mmol N/m2/d)

Submitted

April 2005

e-Citation

Mongin, M., D.M. Nelson and P. Pondaven.; U.S. JGOFS Synthesis & Modeling Project - Data. U.S. JGOFS. iPub: June 2005. 'date you accessed the data' http://usjgofs.whoi.edu/las/servlets/datasets

References

Mongin, M., D.M. Nelson, P. Pondaven, M.A. Brzezinski and P. Treguer. 2003. Simulation of upper-ocean biogeochemistry with a flexible-composition phytoplankton model: C, N and Si cycling in the western Sargasso Sea. Deep-Sea Research I 50:1445-1480.

Contact

Mathieu Mongin
Institut Universitaire EuropC)en de la Mer - UMR CNRS 6539
Technopole Brest-Iroise
Place Nicolas Copernic
F-29280 Plouzané, France
tel: 541-737-21-86
email: mongin@univ-brest.fr

Flexible-composition biogeochemical model results in the western Sargasso Sea - BATS