\(\newcommand{\p}[1]{\frac{\partial }{\partial #1}}\) \(\newcommand{\pp}[2]{\frac{\partial #1}{\partial #2}}\) \(\newcommand{\dd}[2]{\frac{d #1}{d #2}}\) \(\newcommand{\h}{\frac{1}{2}}\) \(\newcommand{\op}[1]{\operatorname{#1}}\)

8.7.3.12. Mortality and Respiration

Respiration and mortality stop at \({c}_j^{\min}\) (maybe should not use \({c}_j^{\min}\) for respiration?)

\[R^{\mathrm{C}}_j = r^{{{\text{resp}}}}_j f^{{{\text{remin}}}}(T) ({c}_j - {c}_j^{\min})\]
\[M_j = m^{(1)}_j {f^{\op{mort}}(T)}^{e^{\op{m}}_j} ({c}_j - {c}_j^{\min}) + m^{(2)}_j {f^{\op{mort2}}(T)}^{e^{\op{m2}}_j} ({c}_j - {c}_j^{\min})^2\]

The released matter splits into dissolved and particulate organic pools,

\[\begin{split}M^{\op{DOM}}_j &= (1 - f_j^{\exp\op{m}}) m^{(1)}_j {f^{\op{mort}}(T)}^{e^{\op{m}}_j} ({c}_j - {c}_j^{\min}) \\ &+ (1 - f_j^{\exp\op{m2}}) m^{(2)}_j {f^{\op{mort2}}(T)}^{e^{\op{m2}}_j} ({c}_j - {c}_j^{\min})^2\end{split}\]
\[\begin{split}M^{\op{POM}}_j &= f_j^{\exp\op{m}} m^{(1)}_j {f^{\op{mort}}(T)}^{e^{\op{m}}_j} ({c}_j - {c}_j^{\min}) \\ &+ f_j^{\exp\op{m2}} m^{(2)}_j {f^{\op{mort2}}(T)}^{e^{\op{m2}}_j} ({c}_j - {c}_j^{\min})^2\end{split}\]

8.7.3.12.1. Parameters

Table 8.40 Mortality and respiration parameters

Trait

Param

Symbol

Default

Units

Description

respRate

a,b_respRate_c 1

\(r^{\op{resp}}_j\)

0

s-1

respiration rate

qcarbon

a,b_qcarbon

\(Q^{\mathrm{c}}_j\)

1.8E-11

mmol C cell–1

cellular carbon content

mort

a_mort

\(m^{(1)}_j\)

0.02 / day

s-1

linear mortality rate

mort2

a_mort2

\(m^{(2)}_j\)

0

m3 s / mmol C

quadratic mortality coefficient

Xmin

a_Xmin

\(c^{\min}_j\)

0

mmol C m-3

minimum abundance for mortality, respiration and exudation

tempMort

grp_tempMort

\(e^{\op{m}}_j\)

1

1: mortality is temp. dependent, 0: not

tempMort2

grp_tempMort2

\(e^{\op{m2}}_j\)

1

1: quadr.tic mortality is temperature dependent, 0: not

ExportFracMort

a_ExportFracMort

\(f^{\op{exp}\op{m}}_j\)

0.5

fraction of linear mortality to POM

ExportFracMort2

a_ExportFracMort2

\(f^{\op{exp}\op{m2}}_j\)

0.5

fraction of quadratic mortality to POM

1

the units of a_respRate_c are mmol C cell–1, see discussion below.

The respiration rate follows a different scaling law from other traits: it scales in terms of cellular carbon content,

\[r^{\op{resp}}_j = \frac{\op{a\_respRate\_c(g)}}{Q^{\mathrm{c}}_j} \left( 12\cdot10^9 \cdot Q^{\mathrm{c}}_j \right)^{\op{b\_respRate\_c(g)}}\]

where

\[Q^{\mathrm{c}}_j = \op{a\_qcarbon(g)} \cdot V_j^{\op{b\_qcarbon(g)}} \;.\]

The units of a_respRate_c are mmol C cell–1 s–1. It now defaults to zero. In the quota model, the default was 3.21·10–11/86400.