1Laboratoire d'analyse, géométrie et applications, université Paris 13, 93430 Villetaneuse, France
2Laboratoire de météorologie dynamique, École polytechnique – IPSL, 91128 Palaiseau, France
3Laboratoire des sciences du climat et de l'environnement, CEA – IPSL, 91191 Gif-sur-Yvette, France
Received: 04 Mar 2015 – Discussion started: 30 Jun 2015
Abstract. An efficient, local, explicit, second-order, conservative interpolation algorithm between spherical meshes is presented. The cells composing the source and target meshes may be either spherical polygons or latitude–longitude quadrilaterals. Second-order accuracy is obtained by piece-wise linear finite-volume reconstruction over the source mesh. Global conservation is achieved through the introduction of a
Revised: 20 Apr 2016 – Accepted: 13 Jul 2016 – Published: 30 Jan 2017
supermesh, whose cells are all possible intersections of source and target cells. Areas and intersections are computed exactly to yield a geometrically exact method. The main efficiency bottleneck caused by the construction of the supermesh is overcome by adopting tree-based data structures and algorithms, from which the mesh connectivity can also be deduced efficiently.
The theoretical second-order accuracy is verified using a smooth test function and pairs of meshes commonly used for atmospheric modelling. Experiments confirm that the most expensive operations, especially the supermesh construction, have O(NlogN) computational cost. The method presented is meant to be incorporated in pre- or post-processing atmospheric modelling pipelines, or directly into models for flexible input/output. It could also serve as a basis for conservative coupling between model components, e.g., atmosphere and ocean.
Kritsikis, E., Aechtner, M., Meurdesoif, Y., and Dubos, T.: Conservative interpolation between general spherical meshes, Geosci. Model Dev., 10, 425-431, doi:10.5194/gmd-10-425-2017, 2017.