Photophysiological adaptations of polar phytoplankton and the impact on satellite-derived primary production estimates

Ocean color satellite remote sensing provides extensive access to the highly seasonal, regionally variable, and rapidly changing Arctic Ocean. However, because polar phytoplankton are adapted to perpetually low-light conditions and cold temperatures, satellite-derived estimates of net primary production (NPP) must take into account the unique photophysiological characteristics that impact phytoplankton photosynthesis and growth. This study presents extensive photophysiological data measured on multiple recent polar cruises across various stages of a seasonal bloom cycle. These measurements, which include phytoplankton growth rates, net primary production, photosynthesis versus irradiance, and absorption, are leveraged to improve the parameterization of an existing model to estimate NPP from satellite chlorophyll a, sea surface temperature, and irradiance.