after Wilde (1987)

CLIMATE: | ATMOSPHERE | |||
---|---|---|---|---|

Glacial |
Pre-Post Glacial |
Non Glacial |
PAL |

## Average Redox through the Pycnocline |
---|

Ts | Temperature mixed layer | |||
---|---|---|---|---|

Td | Temperature deep water | |||

dT | Range in pycnocline | |||

z_{s} | Thickness upper mixed layer | |||

dz | Thickness of pycnocline | |||

dT/dz | Pycnocline T gradient | |||

Os | Oxident in mixed layer | |||

Od | Oxident in deep layer | |||

Z_{oxm} | Depth of Prod. max | |||

w | Vertical Advection*10^{6} |

a | R_{0} | A | C1 | C2 | C3 |
---|

**D.O. at Specific Depth within the Pycnocline**

Depth | DO |
---|

The model assumes that the oxidative decay proceeds (Riley, 1951; Wyrtki, 1962, p. 13) as:

R = rate of decay at depth Z

R

a = function of oxidized substance

Z = depth

and the steady state concentration of oxygen (O_{x}) can be found by the solution of:

A = vertical exchange coefficient

w = vertical advection

Wyrtki (1961, p. 44) has shown how the temperature profile can be used to calculate w/A from the expression:

wT - A T/z = wT_{D}................... (3)

T = potential temperature at given depth

T

assuming, within the main thermocline, that (1) w is constant and (2) A is at a minimum. For the
central part of the modern ocean he estimated that w = 2 x10^{-5} cm/sec and A = 0.5 cm^{2}/sec were
reasonable.

As noted in the text in eq (2) the concentration of oxygen can be modeled as:

A = vertical exchange coefficient

w = vertical advection

R = R

The solution of eq (2) for Os (oxidant) is:

O_{x}=C_{1} + C_{2}e^{-(w/A)Z} + C_{3}e^{-aZ}

where the constants of integration are:

C_{1} = Ox (@ upper boundary) - C_{2}e^{-(w/A)Z (@upper boundary) } - C_{3}e^{-aZ(@ upper boundary)};

C2 = [{Ox (@ upper boundary)--Ox (@ lower boundary)} -

{C_{3}e^{-aZ (@ Upper boundary)} +C_{3}e^{-aZ (@ Lower boundary)}} /

{e^{-(w/A)Z (@ Upper boundary)} - e^{-(w/A)Z (@ Lower boundary)}} ];

C_{3} = Ro/Aa(a - w/A)

Taken as constants are a = 0.000025 and Ro = 7.5 X 10^{-9}.

Taken as constant for a particular climate (table 1) is the ratio (w/A), which is related to variation in temperature in the thermocline.