During April 2025, Alex stabilized ocean model cavity handling in the FESOM/fesom2 repository, focusing on preventing surface height drift and model blowups. He reverted the model to a rigid lid approach for cavity regions and refined the logic for updating surface-related variables, ensuring changes only occurred when vertical levels exceeded one. By correcting the SSH right-hand side calculations for both cavity and open-ocean scenarios, Alex improved the model’s accuracy and robustness. His work, implemented in Fortran and leveraging skills in numerical simulation and ocean modeling, addressed a critical bug, resulting in more stable and reliable surface height calculations within the codebase.