Southern Ocean Seasonal Experiment 2022 (SCALE-WIN22) on the SA Agulhas II Voyage 053, July 2022

This cruise, conducted on the SA Agulhas II Voyage 053 in July 2022, was included as a final component of the SCALE programme (Southern oCean seAsonaL Experiment, https://scale.org.za), a bottom-up endeavour of the SA scientific community to address the limited multidisciplinary knowledge on the seasonal cycle of the Southern Ocean. The seasonal cycle is an important mode of variability that couples the physical mechanisms of climate forcing to ecosystem response in phytoplankton diversity, primary production, and carbon export. Model simulations of the Southern Hemisphere tend to misestimate the magnitude and miss the timing of the Southern Ocean seasonal cycle both in terms of the seasonality of surface ocean warming and cooling, sea ice advancement/retreat, carbon dioxide exchanges and simulated primary production. Our capability to predict the ongoing shifts and future responses is therefore limited. This drives the need for more physical and biogeochemical data sets that address the problem of knowledge and model biases; firstly, to identify them, and secondly to characterise the associated mechanisms that will allow improved projections.