, which greatly improved the readability and presentation of this paper; and to Colin Cotter, Tom Melvin and Golo Wimmer for many illuminating discussions about the application of Hamiltonian and compatible Galerkin methods for geophysical fluids. We are also thankful to David Ham, Lawrence Mitchell and Miklos Homolya for assistance with development of Themis, without which this work would have been much harder, We are grateful to Colin Cotter and Almut Gassmann for their detailed and thorough reviews

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