# chemical oceanography

posted by
**josh**
.

Avg PO4^3- []'s in the deep and surface ocn's are 2.11 and 0.71umolkg^-1. Calc the residence time of PO4^3- in the deep ocn considering the carbon budget(Figure below) Write the general equation, calculation and units.

------ represents a Box outline

Surface---------------------------------

[P]surface

------------/\-----------------;;;;-----

---------\/--------------------;;;;-----

(arrows moving up and down through surface and deep) ventilation =4.6 m/y

;;;;=(sinking)

Jc = 5.0Gt/y

deep------------;;;;--------------------

----------------;;;;--------------------

;;;;=(sinking)

Bc = 0.15Gt/y

sediments-------------------------------