Remineralization Ratios in the Subtropical North Pacific Gyre

Yuan-Hui Li, David M. Karl, Christopher D. Winn, Fred T. Mackenzie and Kathleen Gans

Dept of Oceanography, University of Hawaii, Honolulu, HI 96822

Abstract

Based on a new mixing model of two end-members, the water column remineralization ratios of P/N/C_org - O₂ = 1/13 ± 1/135 ± 18/170 ± 9 are obtained for the Hawaii Ocean Time-series (HOT) data set at station ALOHA. The traditional Redfield ratios of P/N/C_org/-O₂ = 1/16/106/138 have standard deviations of more than 50%, when they are based on the average composition of phytoplankton. Apparently, the remineralizition processes in the water column have smoothed out the observed large variability of plankton compositions. A new molar formula for the remineralized plankton may be written as C₁₃₅H₂₈₀O₁₀₅N₁₃P or C₂₅(CH₂O)₁₀₁(CH₄)₉(NH₃)₁₃(H₃PO₄).

Oxidation of this formula results in:

C₂₅(CH₂O)₁₀₁(CH₄)₉(NH₃)₁₃(H₃PO₄) + 170O₂ -> 135CO₂ + 132H₂O + 13NO^-₃ + H₂PO^-₄ + 14H⁺

For comparison, remineralization using Redfields formula gives:

(CH₂O)₁₀₆(NH₃)₁₆(H₃PO₄) + 138O₂ -> 106CO₂ + 122H₂O + 16NO^-₃ + H₂PO^-₄ + 17H⁺