Description
Summary:International audience Phytoplankton in Antarctic coastal polynyas has a temporally short yet spatially variant growthwindow constrained by ice cover and day length. Using 18-year satellite measurements (1997–2015) of seaice and chlorophyll concentrations, we assessed the synchronicity between the spring phytoplankton bloomand light availability, taking into account the ice cover and the incident solar irradiance, for 50 circum-Antarcticcoastal polynyas. The synchronicity was strong (i.e., earlier ice-adjusted light onset leads to earlier bloom andvice versa) in most of the western Antarctic polynyas but weak in a majority of the eastern Antarctic polynyas.The west-east asymmetry is related to sea ice production rate: the formation ofmany eastern Antarctic polynyasis associated with strong katabatic wind and high sea ice production rate, leading to stronger water columnmixing that could damp phytoplankton blooms and weaken the synchronicity.