Coexchangeable process modelling for uncertainty quantification in joint climate reconstruction ...

• Main Authors: Astfalck, Lachlan, Williamson, Daniel, Gandy, Niall, Gregoire, Lauren, Ivanovic, Ruza
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: arXiv 2021
• Subjects: Applications stat.AP; FOS Computer and information sciences; Sea ice
• Online Access: https://dx.doi.org/10.48550/arxiv.2111.12283; https://arxiv.org/abs/2111.12283

Any experiment with climate models relies on a potentially large set of spatio-temporal boundary conditions. These can represent both the initial state of the system and/or forcings driving the model output throughout the experiment. Whilst these boundary conditions are typically fixed using available reconstructions in climate modelling studies, they are highly uncertain, that uncertainty is unquantified, and the effect on the output of the experiment can be considerable. We develop efficient quantification of these uncertainties that combines relevant data from multiple models and observations. Starting from the coexchangeability model, we develop a coexchangable process model to capture multiple correlated spatio-temporal fields of variables. We demonstrate that further exchangeability judgements over the parameters within this representation lead to a Bayes linear analogy of a hierarchical model. We use the framework to provide a joint reconstruction of sea-surface temperature and sea-ice concentration ... : Accepted with major revisions in the Journal of the American Statistical Association, resubmission is in review ...