Annual variations in phytoplankton biomass driven by small-scale physical processes Keerthi, M. G. Prend, C. J. /Aumont, Olivier /Levy, Marina Phytoplankton biomass exhibits substantial year-to-year changes, and understanding these changes is crucial to fisheries management and projecting future climate. These annual changes result partly from low-frequency climate modes that also lead to variations in sea surface temperature (SST). Here we evaluate the contribution of small scales to annual fluctuations based on a global analysis of satellite observations of sea surface chlorophyll (SChl), an indicator of phytoplankton biomass, and of SST from 1999 to 2018. We disentangle the spatio-temporal scales of variability in the time series and find that besides the prominent seasonal cycle, SChl is dominated by high-frequency fluctuations (<three months) at small spatial scales (<50 km)-which accumulates over annual scales in contrast to SST. The results suggest that observations and models with high spatio-temporal resolutions are necessary to understand annual changes in SChl. The rapid response of SChl to small-scale physical processes, combined with intrinsic ecosystem interactions and air-sea interaction feedbacks, may explain the differences between annual variations in SST and SChl. Annual variations of phytoplankton biomass can be explained by processes acting on small spatio-temporal scales, according to a global analysis of satellite observations of sea surface chlorophyll and temperature from 1999 to 2018. 2022 text https://www.documentation.ird.fr/hor/fdi:010089890 fdi:010089890 Keerthi M. G., Prend C. J., Aumont Olivier, Levy Marina. Annual variations in phytoplankton biomass driven by small-scale physical processes. 2022, 15, 1027-1033 EN MONDE