What we have learned from SOSCEx: A high-resolution glider experiment in the sub-Antarctic Southern Ocean

Abstract

In the Southern Ocean there is increasing evidence that seasonal to sub-seasonal temporal scales, and meso- to submeso- spatial scales play an important role in understanding the sensitivity of ocean primary productivity to climate change. In addition, there appear to be important regional and basin scale differences in the way that ocean productivity responds to the otherwise regular seasonal forcing, which is not well understood (Thomalla et al., 2011.. These knowledge gaps in this globally important region provide the stimulus for a high-resolution approach to characterizing the drivers of variability of the seasonal cycle of phytoplankton distribution and primary production. Here we summarise the key insights from a series of glider deployments in the Sub-Antarctic Zone (SAZ. that form part of the Southern Ocean Seasonal Cycle Experiment (SOSCEx., which highlight: 1. the important role of small scale variability in driving vertical stratification and early blooms in spring and mixed layer variability and sustained blooms in summer (Swart et al., 2015, du Plessis et al., 2017.; 2. The seasonal progression of net community production and sensitivity to fine-scale dynamics (Thomalla et al., 2015.; 3. Seasonal trends and sub-seasonal variability in chlorophyll to carbon ratios (Thomalla et al., 2017. and 4. The requirement to subsample the SAZ frequencies of less than 10 and 2 days to adequately characterise the seasonal scales of variability in chlorophyll and CO2 flux respectively (Monteiro et al., 2015; Little et al., in prep.. These results highlight the need for climate models to resolve both the meso- to submesoscale and subseasonal processes in order to accurately reflect the phenology of the phytoplankton community and understand the sensitivity of ocean primary productivity to climate change. - Abstract as displayed in the - Abstract booklet. The presentation on the day may differ from the - Abstract.