The compensation irradiance for phytoplankton in nature



[1] The compensation irradiance for phytoplankton is calculated from the time course of fluorescence-derived chlorophyll-a measured on moored sensors in the North Atlantic in spring. Following the initiation of the spring bloom, the time at which chlorophyll-a begins to decrease at a particular depth in a stratified water column is used to compute the compensation irradiance from the critical depth criterion. Over the depth range of 50–110 m, the compensation irradiance is estimated to be in the range from 0.1–0.3 mol photons m−2 d−1.