Variational Solver Validation

Description
Validation of the variational solver using the partial conjugate gradient method in JEDI for the atmospheric deterministic analysis. Increments between the GSI and JEDI will be compared and verified when using the same model background and assimilated observations. Analysis constraints, variational bias correction coefficient updates, IAU, and other features required for GDAS will be validated or their status will be documented. Timing and reproducibility tests will also be performed and any optimization needs will be shared with JCSDA and other partners.

Deliverables
GitHub issues documenting the deterministic analysis validation efforts (figures, statistics, etc.)
Slide deck summarizing results and any known differences to be shared with JCSDA and NCEP leadership
Document summarizing the status of all requirements from JEDI to replace GSI for GDAS at the end of Q3FY24 and share with JCSDA and NCEP leadership

Review the stated validation scope for the JEDI partial conjugate gradient solver and compare the GSI and JEDI atmospheric deterministic analyses using the same background and observations. Track analysis constraints, bias correction updates, IAU, timing, and reproducibility, then document results through GitHub issues, a slide deck, and a requirements-status document.