Tracer from the Sky

Abstract

The rate of marine photosynthesis is of great importance for the global carbon cycle but is difficult to measure from environmental properties or in vitro. In this Perspective, Bender highlights a study by Luz and Barkan, who exploit the anomalous isotopic composition of molecular oxygen to determine the gross rate of photosynthesis in seawater. The method allows much longer time scales and larger spatial scales to be covered than with traditional oceanographic techniques.