Coccolithophore counts from polarized microscopy birefringence measurements of samples collected in the Northwest Atlantic during R/V Endeavor cruise EN616 in July 2018

Abstract

This dataset presents polarized microscopy-derived concentration data for coccolithophores and detached coccoliths in samples collected from stations in the Northwest Atlantic during R/V Endeavor cruise EN616 in July 2018. Counts are based on image analysis of dark-field, cross-polarized views of filtered particulate matter. These counts take advantage of the birefringence property of calcium carbonate (particulate inorganic carbon) that it rotates the plane of linearly polarized incident light by 90 degrees. Incident light directed upwards, towards the microscope slide, is polarized 90 degrees with a linear polarizer. Particles are viewed from above the slide, through a second, linear polarizer filter held between the microscope stage and the camera which only accepts light that is polarized orthogonal to the lower polarizer. Calcium carbonate particles in the beam appear as bright dots of light. Image analysis software then analyzes the pattern of birefringence and enumerates only those particles with size and shape of coccolithophores or detached coccoliths.

For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/887863