Premium
Revising Estimates of Aquatic Gross Oxygen Production by the Triple Oxygen Isotope Method to Incorporate the Local Isotopic Composition of Water
Author(s) -
Manning Cara C.,
Howard Evan M.,
Nicholson David P.,
Ji Brenda Y.,
Sandwith Zoe O.,
Stanley Rachel H. R.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl074375
Subject(s) - seawater , composition (language) , oxygen , isotopes of oxygen , salinity , oxygen 18 , stable isotope ratio , isotope , chemistry , environmental science , analytical chemistry (journal) , environmental chemistry , geology , oceanography , physics , nuclear chemistry , organic chemistry , quantum mechanics , philosophy , linguistics
Abstract Measurement of the triple oxygen isotope (TOI) composition of O 2 is an established method for quantifying gross oxygen production (GOP) in natural waters. A standard assumption to this method is that the isotopic composition of H 2 O, the substrate for photosynthetic O 2 , is equivalent to Vienna standard mean ocean water (VSMOW). We present and validate a method for estimating the TOI composition of H 2 O based on mixing of local meteoric water and seawater H 2 O end‐members, and incorporating the TOI composition of H 2 O into GOP estimates. In the ocean, GOP estimates based on assuming the H 2 O is equivalent to VSMOW can have systematic errors of up to 48% and in low‐salinity systems, errors can be a factor of 2 or greater. In future TOI‐based GOP studies, TOI measurements of O 2 and H 2 O should be paired when the H 2 O isotopic composition is expected to differ from VSMOW.