Table 3.

Model Parameters

Symbol	Parameter	Value/Units/Reference
θ 1	molar N to C ratio Phytoplankton	0.1509 mol N (mol C)–1 [Redfield et al., 1963]
θ 2	molar N to C ratio Bacteria	0.2000 mol N (mol C)–1 [Kirchman, 2000]
θ 3	molar N to C ratio DOM	0.0667 mol N (mol C)–1 [Benner et al., 1992]
θ 4	molar N to C ratio Phytodetritus	0.1333 mol N (mol C)–1 [Walsh et al., 1999]
θ 5	molar N to C ratio TCDOC	0.0250 mo l N (mol C)–1 [Ertel et al., 1986]
υ 1	molar P to C ratio Phytoplankton	0.0094 mol P (mol C)–1 [Redfield et al., 1963]
υ 2	molar P to C ratio Bacteria	0.0189 mol P (mol C)–1 [Kirchman, 2000]
υ 3	molar P to C ratio DOMa	mol P (mol C)–1 [Lucea et al., 2003]
υ 4	molar P to C ratio Phytodetritus	0.0040 mol P (mol C)–1 [Paytan et al., 2003]
b	coefficient of NH3 uptake	1.5 (dimensionless) [Walsh et al., 1999]
κ	Particulate detritus solubilization rate	0.132 day–1 [Walsh et al., 1999]
GGE	bacterial Gross Growth Efficiency	0.3 Corg ass (Corg uptake)–1 [del Giorgio and Cole, 2000]
β	Fraction of TCDOC photolysis yield to labile DOC	0.1 mole C DOC (mole C photo)–1 (calibratedb)
η 1	photosynthetic quotient NO3 assimilation	1.3 mol O2 per mol C ass.[Laws, 1991; Redfield et al., 1963]
η 2	photosynthetic quotient NH4 assimilation	1.0 mol O2 per mol C assimilated [Laws, 1991]
η 3	phytoplankton respiration quotient	1.0 mol O2 per mol C respired [Laws, 1991]
η 4	bacteria respiration quotient	1.0 mol O2 per mol C respired [Laws, 1991]
η 5	photolytic remin quotient	1.0 mol O2 per mol C photochm. altered [Amon and Benner, 1996]
η 6	Nitrification O2 ratio	2.0 mol O2 per mol NH4 to NO3 (stoichiometryc)
Φ c	Carbon specific quantum yield of Photosynthesis	0.075 mol C (mol photons)–1 [Wozniak et al., 2002]
gm20	maximum gross assimilation rate for phytoplankton @ 20°C	0.12 hr–1 [Walsh et al., 1999]
gmb20	maximum gross assimilation rate for bacteria @ 20°C	0.24 hr–1 [Kemp et al., 1993]
n1	MM half saturation constant phytoplankton DIN	0.5 mmol C m–3 [Walsh et al., 1999]
n2	MM half saturation constant phytoplankton DIP	0.25 mmol P m–3 [Riegman et al., 2000]
n3	MM half saturation constant bacterial DOC	0.83 mmol C m–3 [Walsh et al., 1999]
n4	MM half saturation constant bacterial DIN	0.10 mmol N m–3 [Vallino et al., 1996]
n5	MM half saturation constant bacterial DIP	0.10 mmol P m–3 [Holm and Armstrong, 1981]
Dr	maximum denitrification rate	0.01 day–1 [Herzfeld and Hamilton, 2000]
Nr	maximum nitrification rate	0.05 day–1 [Herzfeld and Hamilton, 2000]
wd1	small detritus sinking rate	0.25 m day–1 (estimated)
wd2	large detritus sinking rate	2.50 m day–1 [Walsh et al., 1999]
wd3	sediment sinking rate	5.00 m day–1 [Walsh et al., 1999]
Kt	temperature coefficient	0.063°C–1 (calibrated to Q10)
ε 1	maintenance respiration rate of Phytoplankton	0.015 day–1 [Geider, 1992]
ε 2	maintenance respiration rate of Bacteria	0.015 day–1 [Geider, 1992]
α 1	fraction of grazed P carbon respired	0.35 [Walsh et al., 1999]
α 2	fraction of grazed P carbon to DOC	0.50 [Walsh et al., 1999]
α 3	fraction of grazed P carbon to SDET	0.10(2/3 of 0.15)
α 4	fraction of grazed P carbon to LDET	0.05(1/3 of 0.15)
α 5	fraction of solubilized particulate detritus	0.212 (calibratedd)
C:Chl	Carbon to Chlorophyll ratio	~50–150 mg C (mg Chl-a)–1 (Redalje unpublished)e
Pt	Minimum (threshold) phytoplankton carbonf	0.2 mmol C m–3 (0.1 ug Chl-a L–1) [Ducklow, 2000]
Bt	Minimum (threshold) bacterioplankton carbon	0.2 mmol C m–3 [Ducklow, 2000]

^aDOP/DOC ratios in coastal marine environments are often <<0.00067 [Hopkinson et al., 1997; Lucea et al., 2003; Hopkinson et al., 2002]. It is assumed that particulate organic phosphorus is remineralized whenever carbon is transferred to the DOC pool.

^bCalibrated from apparent quantum yield studies of terrigenous humics for NH₄ yield and labile organic carbon yield.

^cThe ideal stoichiometry for ammonium nitrification is ${\mathrm{NH}}_4^{+}+1.5\mathrm{O}2={\mathrm{NO}}_2^{-}+{\mathrm{H}}_2\mathrm{O}+2{\mathrm{H}}^{+}$; nitrite nitrification is ${\mathrm{NO}}_3^{-}+0.5\mathrm{O}2=\mathrm{NO}{3}^{-}$; for a total yield of 2 moles O₂. If photosynthetic nitrate assimilation yields 8.6 moles O2 (per mole N), while respiration of phytoplankton carbon yields 7.6 moles O₂ (per mole N) – then 2 moles O₂ consumption per nitrified mole N are required for Redfield stoichiometry (C:N:P:-O₂ = 106:16:1:-138).

^dAssuming the remineralization of phytodetritus is due to particle adhesive bacteria of a C:P ratio = 53 and that DOM contains negligible DOP, then the bacteria must remineralize ~21% of the solubilized phytodetritus.

^eMean C:Chl ratio for the northern Gulf of Mexico ~50, as cited in Dagg [1995]; the range is adjusted to account for low light conditions.

^fThreshold carbon values are required for numerical stability; no loss processes occur below the threshold values.