Improving climate models and projections using observations

A three-day workshop took place from June 12 to 14, 2023, at MIT, Cambridge,Massachusetts, focusing on data assimilation (DA) and machine learning (ML) in the contextof Earth system reanalysis and climate model improvements.The workshop, organized 25 years after the inception of the Estimating the Circulation andClimate of the Ocean (ECCO), was an effort to lay out the roadmap for future development ofDA in support of climate modeling and climate knowledge improvements, or “climate DA”. Thefollowing is a summary of the workshop outcomes and recommendations arising to move thefield of DA forward in the context of climate modeling.