
Guillaume Vernieres developed and enhanced marine data assimilation and modeling workflows across repositories such as NOAA-EMC/GDASApp and JCSDA-internal/soca. He engineered robust C++ and Python solutions for data processing, including grid interpolation, quality control, and automated verification pipelines. His work integrated advanced configuration management using YAML and CMake, enabling reproducible builds and streamlined CI/CD. By introducing features like Gaussian grid state conversion and machine learning-based ice emulation, Guillaume improved data interoperability and model fidelity. His contributions addressed operational reliability, maintainability, and scientific accuracy, demonstrating depth in backend development, scientific computing, and cross-repository integration for large-scale oceanographic systems.

December 2025 monthly summary for JCSDA SOCA: Delivered a new Gaussian Grid State Data Converter to enable conversion of state data to a structured Gaussian grid format, including new source code, tests, and build system integration. No major bugs fixed this month. Overall impact: improves data interoperability and automation of the data processing pipeline, enhances reproducibility and maintainability. Technologies/skills demonstrated: CMake integration, unit testing, executable development, and grid interpolation concepts.
December 2025 monthly summary for JCSDA SOCA: Delivered a new Gaussian Grid State Data Converter to enable conversion of state data to a structured Gaussian grid format, including new source code, tests, and build system integration. No major bugs fixed this month. Overall impact: improves data interoperability and automation of the data processing pipeline, enhances reproducibility and maintainability. Technologies/skills demonstrated: CMake integration, unit testing, executable development, and grid interpolation concepts.
2025-10 Monthly Summary: Implemented robust date handling, configuration simplifications, and CI/test improvements across NOAA-EMC/GDASApp, JCSDA-internal/soca, and NOAA-EMC/jcb-gdas. The work reduced operational risk, simplified configuration, and enhanced reporting visibility, delivering business value through more reliable deployments and clearer diagnostics.
2025-10 Monthly Summary: Implemented robust date handling, configuration simplifications, and CI/test improvements across NOAA-EMC/GDASApp, JCSDA-internal/soca, and NOAA-EMC/jcb-gdas. The work reduced operational risk, simplified configuration, and enhanced reporting visibility, delivering business value through more reliable deployments and clearer diagnostics.
September 2025 monthly summary: Delivered a mix of new capabilities and reliability fixes across three NOAA-EMC repositories, driving enhanced data quality, broader product outputs, and more robust pipelines. The work strengthened marine data processing, improved metadata hygiene, and simplified configuration, all while maintaining a strong emphasis on business value and operational stability.
September 2025 monthly summary: Delivered a mix of new capabilities and reliability fixes across three NOAA-EMC repositories, driving enhanced data quality, broader product outputs, and more robust pipelines. The work strengthened marine data processing, improved metadata hygiene, and simplified configuration, all while maintaining a strong emphasis on business value and operational stability.
2025-08 Monthly Summary: Delivered targeted codebase cleanup, interpolation workflow enhancements, and dependency fixes across three repositories to reduce maintenance burden and improve data readiness. Key outcomes include (1) removal of obsolete marine data assimilation scripts in NOAA-EMC/GDASApp to simplify maintenance; (2) grid interpolation enhancement converting tripolar to Gaussian grid with land/sea-ice flood fill for SST and sea-ice concentration, enabling cleaner downstream data preparation; (3) MOM6 submodule upgrade to emc/dev with build cleanup in JCSDA-internal/soca to ensure the latest model and a cleaner build; (4) MKL dependency resolution in NOAA-EMC/obsForge to fix missing MKL by loading intel-oneapi-mkl/2024.2.1 in the Hercules module. These changes reduce technical debt, stabilize production pipelines, and improve readiness for downstream data products and collaborations.
2025-08 Monthly Summary: Delivered targeted codebase cleanup, interpolation workflow enhancements, and dependency fixes across three repositories to reduce maintenance burden and improve data readiness. Key outcomes include (1) removal of obsolete marine data assimilation scripts in NOAA-EMC/GDASApp to simplify maintenance; (2) grid interpolation enhancement converting tripolar to Gaussian grid with land/sea-ice flood fill for SST and sea-ice concentration, enabling cleaner downstream data preparation; (3) MOM6 submodule upgrade to emc/dev with build cleanup in JCSDA-internal/soca to ensure the latest model and a cleaner build; (4) MKL dependency resolution in NOAA-EMC/obsForge to fix missing MKL by loading intel-oneapi-mkl/2024.2.1 in the Hercules module. These changes reduce technical debt, stabilize production pipelines, and improve readiness for downstream data products and collaborations.
July 2025 performance summary for JCSDA-internal/soca: Focused on expanding model fidelity and robustness of ML-based balancing. Key delivery includes MOM6 integration and ALE enhancements, enabling updated physics and improved diagnostics; commits reflect updating MOM6 to f9e6e2e and adding ALE reconstruction, diagnostics, framework, parameterizations, and tracer-related source files in mom6_files.cmake, with removal of an obsolete file (commit a5baef03317f6ddf737ae06177b03da68a4be826); and a robustness fix for ML Balance Jacobian when B-resolution differs from background, including mask/ghost checks and updated reference data paths (commit 1e487d1888e7fef5957f8ad995ba0b1e40c043e9). Overall, these changes improve forecasting reliability, scientific reproducibility, and maintainability. Technologies demonstrated: Git submodule updates, MOM6/ALE integration, cmake-based code organization (mom6_files.cmake), input validation and cross-resolution handling.
July 2025 performance summary for JCSDA-internal/soca: Focused on expanding model fidelity and robustness of ML-based balancing. Key delivery includes MOM6 integration and ALE enhancements, enabling updated physics and improved diagnostics; commits reflect updating MOM6 to f9e6e2e and adding ALE reconstruction, diagnostics, framework, parameterizations, and tracer-related source files in mom6_files.cmake, with removal of an obsolete file (commit a5baef03317f6ddf737ae06177b03da68a4be826); and a robustness fix for ML Balance Jacobian when B-resolution differs from background, including mask/ghost checks and updated reference data paths (commit 1e487d1888e7fef5957f8ad995ba0b1e40c043e9). Overall, these changes improve forecasting reliability, scientific reproducibility, and maintainability. Technologies demonstrated: Git submodule updates, MOM6/ALE integration, cmake-based code organization (mom6_files.cmake), input validation and cross-resolution handling.
June 2025 monthly summary for NOAA-EMC development efforts across GDASApp and jcb-gdas. Key features delivered, major bugs fixed, and the resulting business impact, with emphasis on data quality, reliability, and test coverage. Key features delivered: - Ocean Increment Quality Control Improvements: quality-control enhancements for ocean increments, including re-scaling temperature and salinity when sea surface height increments exceed thresholds; addition of a steric height computation utility; refactoring to ensure increments stay within physical bounds. Commits: 2e64ed4f37046cfecd2c15269aad3e00eb5c1258; 1a4beaa2f3e7a72cd061491064a020336753925c0. - Observation Space Configuration Update (noobsda): modify obs_list.yaml.j2 to retain only sst and icec; aligns with noobsda initiative and issue #1741. Commit: a1a1f35ae99cd2a6980f04ec8d624fba8399a5c0. - SOCA Testing Framework and FV3 Coupling Tests: introduce and expand ctests for SOCA apps and add a coupled test case between SOCA and FV3 (gdas_soca_to_fv3.x). Commits: d6ca42dc13a03c4499bbc086574edc17cce1c796; e6f9533560245e3d2eb9aab75df666833dc37986. - Increment Smoothing Reproducibility and QC Updates: address reproducibility of the increment smoothing process across PE layouts and update QC logic for stability and correct bounds. Commit: 5acef4583be5a2ca798b83ac1fd1201dfce7ffad. - Geostrophy Diagnostic Tool: develop a new diagnostic application to compute geostrophic velocities from sea surface height, including new C++ sources, updated build configurations, and CI linting. Commit: a8f311217646ed9ba9d8a8c75c1e0b8248156f45. Major bugs fixed: - Fixed machine-precision reproducibility issues in increment smoothing QC, ensuring consistent results across varying PE layouts. This enhances repeatability for downstream analyses and production runs. Commits: 5acef4583be5a2ca798b83ac1fd1201dfce7ffad. - Tightened QC bounds to prevent physically implausible increments, reducing the risk of data corruption in ocean increment processing. Overall impact and accomplishments: - Significantly increased data quality and reliability for ocean increments and related QC processes, enabling more trustworthy downstream analyses and operational decision support. - Expanded test coverage with ctests for SOCA and FV3 coupling, improving regression safety and CI confidence for cross-application interactions. - Delivered new diagnostic capabilities (geostrophy) to enhance observability of ocean dynamics, supporting better model validation and drift detection. - Improved reproducibility and stability across compute layouts, reducing non-deterministic behavior and enabling reproducible research workflows. - Streamlined observation configuration to align with noobsda, reducing noise and focusing on high-value observations (sst, icec). Technologies/skills demonstrated: - C++ development for geostrophy diagnostics, CI linting, and new build configurations. - Scripting and templating (obs_list.yaml.j2) to drive configuration management. - Comprehensive testing with ctests for SOCA and coupled FV3 scenarios. - Robust QC logic development, including handling of steric calculations and bounds enforcement. - Cross-repo collaboration and integration between GDASApp and jcb-gdas to unify quality improvements and stability checks.
June 2025 monthly summary for NOAA-EMC development efforts across GDASApp and jcb-gdas. Key features delivered, major bugs fixed, and the resulting business impact, with emphasis on data quality, reliability, and test coverage. Key features delivered: - Ocean Increment Quality Control Improvements: quality-control enhancements for ocean increments, including re-scaling temperature and salinity when sea surface height increments exceed thresholds; addition of a steric height computation utility; refactoring to ensure increments stay within physical bounds. Commits: 2e64ed4f37046cfecd2c15269aad3e00eb5c1258; 1a4beaa2f3e7a72cd061491064a020336753925c0. - Observation Space Configuration Update (noobsda): modify obs_list.yaml.j2 to retain only sst and icec; aligns with noobsda initiative and issue #1741. Commit: a1a1f35ae99cd2a6980f04ec8d624fba8399a5c0. - SOCA Testing Framework and FV3 Coupling Tests: introduce and expand ctests for SOCA apps and add a coupled test case between SOCA and FV3 (gdas_soca_to_fv3.x). Commits: d6ca42dc13a03c4499bbc086574edc17cce1c796; e6f9533560245e3d2eb9aab75df666833dc37986. - Increment Smoothing Reproducibility and QC Updates: address reproducibility of the increment smoothing process across PE layouts and update QC logic for stability and correct bounds. Commit: 5acef4583be5a2ca798b83ac1fd1201dfce7ffad. - Geostrophy Diagnostic Tool: develop a new diagnostic application to compute geostrophic velocities from sea surface height, including new C++ sources, updated build configurations, and CI linting. Commit: a8f311217646ed9ba9d8a8c75c1e0b8248156f45. Major bugs fixed: - Fixed machine-precision reproducibility issues in increment smoothing QC, ensuring consistent results across varying PE layouts. This enhances repeatability for downstream analyses and production runs. Commits: 5acef4583be5a2ca798b83ac1fd1201dfce7ffad. - Tightened QC bounds to prevent physically implausible increments, reducing the risk of data corruption in ocean increment processing. Overall impact and accomplishments: - Significantly increased data quality and reliability for ocean increments and related QC processes, enabling more trustworthy downstream analyses and operational decision support. - Expanded test coverage with ctests for SOCA and FV3 coupling, improving regression safety and CI confidence for cross-application interactions. - Delivered new diagnostic capabilities (geostrophy) to enhance observability of ocean dynamics, supporting better model validation and drift detection. - Improved reproducibility and stability across compute layouts, reducing non-deterministic behavior and enabling reproducible research workflows. - Streamlined observation configuration to align with noobsda, reducing noise and focusing on high-value observations (sst, icec). Technologies/skills demonstrated: - C++ development for geostrophy diagnostics, CI linting, and new build configurations. - Scripting and templating (obs_list.yaml.j2) to drive configuration management. - Comprehensive testing with ctests for SOCA and coupled FV3 scenarios. - Robust QC logic development, including handling of steric calculations and bounds enforcement. - Cross-repo collaboration and integration between GDASApp and jcb-gdas to unify quality improvements and stability checks.
Concise monthly summary for 2025-05 focusing on core capability delivery and reliability improvements across SOCA, MOM6 integration, GDASApp, and the global workflow. Highlights include foundational Ocean Sea Ice Emulator, MOM6 with MARBL tracers, Marine Data Assimilation configuration enhancements, improved GDAS background error estimation for ocean/sea-ice, QC improvements for ocean increments, and a release version update for gdas_soca.
Concise monthly summary for 2025-05 focusing on core capability delivery and reliability improvements across SOCA, MOM6 integration, GDASApp, and the global workflow. Highlights include foundational Ocean Sea Ice Emulator, MOM6 with MARBL tracers, Marine Data Assimilation configuration enhancements, improved GDAS background error estimation for ocean/sea-ice, QC improvements for ocean increments, and a release version update for gdas_soca.
April 2025 monthly work summary focusing on delivering end-to-end data processing capabilities and configuration improvements for NOAA-EMC data pipelines. The work prioritized marine observation fidelity, ingestion automation, and readiness for assimilation workflows.
April 2025 monthly work summary focusing on delivering end-to-end data processing capabilities and configuration improvements for NOAA-EMC data pipelines. The work prioritized marine observation fidelity, ingestion automation, and readiness for assimilation workflows.
Monthly summary for 2025-03: Delivered focused improvements across three repositories, strengthening data processing reliability, operational efficiency, and end-to-end CI/CD capabilities. The work demonstrates continued value in data assimilation quality, scalable build pipelines, and robust observation file management.
Monthly summary for 2025-03: Delivered focused improvements across three repositories, strengthening data processing reliability, operational efficiency, and end-to-end CI/CD capabilities. The work demonstrates continued value in data assimilation quality, scalable build pipelines, and robust observation file management.
February 2025 performance summary for NOAA-EMC development teams. Focused on enabling cost-effective, high-quality data assimilation at reduced resolutions, improving variance partitioning, and tightening verification workflows across jcb-gdas, GDASApp, and global-workflow repositories.
February 2025 performance summary for NOAA-EMC development teams. Focused on enabling cost-effective, high-quality data assimilation at reduced resolutions, improving variance partitioning, and tightening verification workflows across jcb-gdas, GDASApp, and global-workflow repositories.
Month: 2025-01 — Focused on automating verification workflows and enriching data visualization in NOAA-EMC/GDASApp. Replaced manual verification submissions with an automated Python-based pipeline and introduced a browsable OMB statistics gallery to speed validation and improve stakeholder access to results.
Month: 2025-01 — Focused on automating verification workflows and enriching data visualization in NOAA-EMC/GDASApp. Replaced manual verification submissions with an automated Python-based pipeline and introduced a browsable OMB statistics gallery to speed validation and improve stakeholder access to results.
December 2024 monthly summary: Delivered meaningful enhancements across NOAA-EMC and partner repos to strengthen marine and global ensemble forecasting, improve configuration management, and stabilize CI. Implemented ensemble variance capability for the marine model, refined GDAS marine ensemble processing, expanded MOM6 IAU increments to include velocity components, tuned CP4 system configurations with enhanced observation filtering, and introduced a marine hybrid ensemble forecast capability. These results improve forecast reliability and uncertainty representation, enable more maintainable configurations, and streamline workflows, delivering measurable business value in forecast quality and operational robustness.
December 2024 monthly summary: Delivered meaningful enhancements across NOAA-EMC and partner repos to strengthen marine and global ensemble forecasting, improve configuration management, and stabilize CI. Implemented ensemble variance capability for the marine model, refined GDAS marine ensemble processing, expanded MOM6 IAU increments to include velocity components, tuned CP4 system configurations with enhanced observation filtering, and introduced a marine hybrid ensemble forecast capability. These results improve forecast reliability and uncertainty representation, enable more maintainable configurations, and streamline workflows, delivering measurable business value in forecast quality and operational robustness.
November 2024 (JCSDA-internal/soca) — Focused on improving model correctness and introducing AI-assisted ice emulation. Delivered a metadata-driven bug fix for ice/sea ice variable extraction and introduced an experimental PyTorch-based ice emulator within the SOCA model. The work enhances physics fidelity, expands modeling capabilities, and establishes groundwork for data-driven components with clear business value in accuracy and maintainability.
November 2024 (JCSDA-internal/soca) — Focused on improving model correctness and introducing AI-assisted ice emulation. Delivered a metadata-driven bug fix for ice/sea ice variable extraction and introduced an experimental PyTorch-based ice emulator within the SOCA model. The work enhances physics fidelity, expands modeling capabilities, and establishes groundwork for data-driven components with clear business value in accuracy and maintainability.
2024-10 Monthly summary: Implemented targeted configuration and data-model improvements for marine and sea ice components. Key features include Marine Ensemble Variance Configuration Refactor (NOAA-EMC/jcb-gdas) simplifying paths and variable names for background error covariance and ensemble weights; and Sea Ice Data: Enhanced Handling with New Fields and Metadata Refactor (JCSDA-internal/soca) adding new sea ice fields, templated metadata, and updated processing for dynamic/thermodynamic variables. Notable cleanup removed derived water pressure variable definition and tightened test coverage. Result: streamlined configuration, clearer data flow, and more robust processing in preparation for accelerated experimentation and better maintainability.
2024-10 Monthly summary: Implemented targeted configuration and data-model improvements for marine and sea ice components. Key features include Marine Ensemble Variance Configuration Refactor (NOAA-EMC/jcb-gdas) simplifying paths and variable names for background error covariance and ensemble weights; and Sea Ice Data: Enhanced Handling with New Fields and Metadata Refactor (JCSDA-internal/soca) adding new sea ice fields, templated metadata, and updated processing for dynamic/thermodynamic variables. Notable cleanup removed derived water pressure variable definition and tightened test coverage. Result: streamlined configuration, clearer data flow, and more robust processing in preparation for accelerated experimentation and better maintainability.
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