September 2025 monthly summary for the FESOM/fesom2 repository focused on correctness and stability in hydrology physics. Delivered a critical bug fix to Antarctic surface runoff masking, removing a conditional that masked runoff south of -60 degrees when cavity physics were enabled. This change ensures surface runoff is no longer artificially zeroed in that region, improving physical fidelity and downstream analyses.

August 2025 monthly summary for FESOM/fesom2: Implemented iceberg-cavity and coastal boundary enhancements to improve heat and freshwater flux calculations, masking Antarctic runoff south of 60° latitude, and refining boundary handling with area-weighted flux computations. Fixed iceberg boundary (icb) heat flux issues and validated stability with checkpoint-style checks. These changes improve model fidelity, budget closure, and predictive value for coastal and ice-ocean interactions.

July 2025 — FESOM/fesom2: WISO restart file handling and tracer initialization enhancements. Refactors ocean I/O initialization, supports WISO restart file naming, enables cold-start workflows, and aligns Adams-Bashforth naming with new WISO file naming. This work improves startup reliability, reproducibility, and modeling workflow for WISO-based runs.

March 2025 monthly summary for esm-tools/esm_tools. Focused on delivering cross-hemisphere coupling capabilities, data processing fidelity, and deployment reliability to accelerate climate-ice interaction research and downstream workflows. Key features delivered: - Dual-hemisphere ESM coupling environment and integration: adds environment preparation, data handling utilities, and atmospheric forcing components for dual-hemisphere simulations, enabling more realistic global ice-sheet–atmosphere coupling. - Atmospheric data downscaling enhancements for PISM: refactors downscaling workflows with clearer elevation-data naming and new configuration options for lapse rate and precipitation downscaling to improve data processing fidelity. - Iceberg coupling/configuration improvements for dual-hemisphere with FESOM: streamlines iceberg/coupling configuration, moves relevant namelist blocks, and simplifies flags to improve reliability of iceberg–ice sheet and FESOM integration. - dEBM model installation script and default namelist: adds a straightforward install script and a default namelist for the dEBM model, enabling easier setup across machines. - Multi-environment PISM configuration and environment setup compatibility: updates to ensure robust environment configuration across multiple computing environments, with correct environment variables for diverse hemispheric configurations. Major bugs fixed: - Orography handling in awiesm-PISM downscaling: fixes how orography is updated when downscaling, improving coupling accuracy. - Time axis path fix in PDD coupling: corrects the file path for the time axis to ensure proper time-dependent data exchange between atmosphere and PISM. - Code cleanup and script readability improvements: removes obsolete debugging code and reorders script options for maintainability. Overall impact and accomplishments: - Improved realism and reliability of dual-hemisphere simulations, enabling more accurate climate-ice interactions. - Easier onboarding and deployment across HPC environments, reducing setup time and errors. - A maintainable, scalable codebase with clearer data processing and configuration workflows. Technologies/skills demonstrated: - PISM, FESOM integration; cross-hemisphere coupling frameworks; atmospheric data downscaling workflows - HPC environment management and multi-environment configuration; namelist-driven configuration; scripting (installers, readiness checks) - Version control discipline and commit traceability for large coupling projects.

February 2025 summary for esm_tools and FESOM2 focusing on delivering features that improve topography handling, tracer transport capability, and configuration/version management, alongside critical stability fixes. The work enhances model accuracy, stability, and reproducibility, enabling faster experimentation and more reliable automated workflows across the integrated AWIESM-FESOM stack.

January 2025: Highlights include robust data handling improvements and accurate outputs in FESOM2, a bug fix ensuring correct sequencing of land ice runoff fluxes, and configuration upgrades in esm_tools to 2.6.4 with transit namelist integration. These changes improve data fidelity, isotope accounting, and configuration management, enabling more reliable modeling and reproducibility across the project.

Month: 2024-11 — Deliveries across esm_tools/esm_tools and FESOM/fesom2 focused on correctness, configurability, and diagnostics with tangible business value. Key work included standardizing boolean configuration handling in ECHAM couplings, exposing multi_year_mean in the ECHAM input config for flexible monthly data handling, iceberg diagnostics enhancement in FESOM2, and wave erosion potential modeling to improve physical realism. These changes reduce misconfigurations, enable more flexible monthly processing, and provide richer diagnostics for iceberg-affected simulations and wave-erosion assessments.

Month: 2024-10 Overview: Focused on enhancing iceberg heat flux modeling in FESOM/fesom2 to improve layer-wise heat coupling and reduce model complexity. Implemented a per-layer heat source representation for iceberg heat input by removing the outgoing heat flux term, aligning with the goal of attributing incoming heat directly to each layer.