Monte-Carlo simulations for Meteorology and Climatology – MC2

The objective of the MC2 project is to develop and validate innovative numerical methods to accurately and efficiently capture the effect of urban complexity in coupled simulations of turbulent flow and heat transfers for weather and climate services. The new approaches developed aims at the scaling up of meteorological and climate simulations to account for the full 3D description of an entire city with various material properties.
New physical models, algorithms and scientific computing libraries will be developed to solve combined heat transfers by probabilistic Monte-Carlo methods having computation time independent of the number of dimensions and the domain complexity unlike all deterministic state-of-the-art approaches. By computing linearized combined transient heat transfers in a single Monte-Carlo algorithm with the advanced computer graphics tools in large and complex city geometry, the Symbolic Monte-Carlo method will enable to speed up computation times by archiving spatial and temporal history of paths capturing linear and non-linear dependencies of the sources and simulation parameters. Free and open source scientific libraries will be developed and disseminate in different scientific communities (Heat transfer, Atmosphere, Climate) such as a city procedural generator or Monte-Carlo algorithms.
The first objective of the MC2 project is to provide high resolution multi-scale and multi-physics simulations of city-atmosphere interactions that account for the complex geometry of cities. A new approach of obstacle-resolving modelling of convection-conduction-radiation in urban environments will be developped and the potential benefits of this new model will be quantified for idealised urban geometries and a real one consisting in a part of Toulouse (France). To this end a probabilistic modelling of heat transfer in complex 3D urban morphology will be integrated in the mesoscale atmospheric model Meso-NH.
The second objective of the MC2 project is to develop fast city models that integrate the city's geometry complexity directly in the atmospheric column for global or regional climate models, thus accounting for the local coupling with the atmosphere in a simplified way. A hierarchy of fast city-models will be developed for climate services where the atmospheric column of the long-term transient climate simulation will be coupled to the city probabilistic heat transfer model to deliver new metrics such as the energy consumption at the scale of several decades and a territory. The fast city-models will be tuned based on the new obstacle-resolving simulations realised in the MC2 project and the uncertainty associated with the downscaling assumptions will be quantified.