The purpose of this special issue is to review and report on recent advances in the design, implementation, and interpretation of ensembles in climate science. This includes theoretical, mathematical, and computational aspects, therefore bringing together contributions from mathematicians, computational scientists, model users and developers, and climate scientists alike.

Climate science, in particular climate prediction and projection, are heavily dependent on the use of Earth system models (ESMs), which are nonlinear, complex, and chaotic representations of the Earth’s spheres. As such, ESMs are susceptible to various sources of uncertainty. These include uncertainty in the initial state, parameter values, model formulation, structure, and external forcing. Ensembles have become a key tool to quantify these uncertainties and improve predictions. However, challenging questions remain regarding how to design and interpret such ensembles within the constraints of limited computational power and the lack of a rigorous framework for their design. Therefore, this special issue will be a valuable resource to climate scientists working on both theoretical and practical aspects of prediction ahead of Phase 7 of the Coupled Model Intercomparison Project (CMIP7) and future assessments.

This issue arises from the minisymposium Theoretical and Computational Aspects of Ensemble Design and Interpretation in Climate Science and Modelling hosted during the SIAM Conference on Mathematical & Computational Issues in Geosciences in Bergen, Norway (19–22 June 2023). It will feature works by participants as well as external contributions.

The nonlinear nature of fluid flow gives rise to a wealth of interesting and beautiful phenomena. Many of these are of fundamental importance in the understanding of lakes, oceans, and the atmosphere because of their role in processes such as transport, the energy cascade, and, ultimately, in mixing. This special issue is intended to bring together researchers interested in the fundamental nature of nonlinear processes in rivers, lakes, oceans, and the atmosphere. Examples include, but are not limited to, nonlinear and solitary waves, wave–current and wave–wave interactions, flow instabilities and their nonlinear evolution, turbulence, frontogenesis, double diffusion and the nonlinear equation of state, convection, and river plumes. Papers on theoretical, modelling, experimental, or observational work are welcome.

The purpose of this special issue is to review and report on recent advances in the design, implementation, and interpretation of ensembles in climate science. This includes theoretical, mathematical, and computational aspects, therefore bringing together contributions from mathematicians, computational scientists, model users and developers, and climate scientists alike.

Climate science, in particular climate prediction and projection, are heavily dependent on the use of Earth system models (ESMs), which are nonlinear, complex, and chaotic representations of the Earth’s spheres. As such, ESMs are susceptible to various sources of uncertainty. These include uncertainty in the initial state, parameter values, model formulation, structure, and external forcing. Ensembles have become a key tool to quantify these uncertainties and improve predictions. However, challenging questions remain regarding how to design and interpret such ensembles within the constraints of limited computational power and the lack of a rigorous framework for their design. Therefore, this special issue will be a valuable resource to climate scientists working on both theoretical and practical aspects of prediction ahead of Phase 7 of the Coupled Model Intercomparison Project (CMIP7) and future assessments.

This issue arises from the minisymposium Theoretical and Computational Aspects of Ensemble Design and Interpretation in Climate Science and Modelling hosted during the SIAM Conference on Mathematical & Computational Issues in Geosciences in Bergen, Norway (19–22 June 2023). It will feature works by participants as well as external contributions.

The nonlinear nature of fluid flow gives rise to a wealth of interesting and beautiful phenomena. Many of these are of fundamental importance in the understanding of lakes, oceans, and the atmosphere because of their role in processes such as transport, the energy cascade, and, ultimately, in mixing. This special issue is intended to bring together researchers interested in the fundamental nature of nonlinear processes in rivers, lakes, oceans, and the atmosphere. Examples include, but are not limited to, nonlinear and solitary waves, wave–current and wave–wave interactions, flow instabilities and their nonlinear evolution, turbulence, frontogenesis, double diffusion and the nonlinear equation of state, convection, and river plumes. Papers on theoretical, modelling, experimental, or observational work are welcome.