International Urban Energy Balance Models Comparison Project: JULES-URBAN models, any winners?

The Joint UK Land Environment Simulator (JULES) currently has a choice of three urban models, which have differing levels of complexity. The simplest model only has one urban tile, while the most complex, which uses the Met Office Reading Urban Surface Exchange Scheme (MORUSES), has two. The question is, are there any clear winners? Do any of these models clearly outperform the others? The three JULES-based urban models were compared in the International Urban Energy Balance Models Comparison Project along with 20 other urban energy balance models. This inter-comparison project is the first large-scale systematic evaluation of these models undertaken. The JULES-URBAN models were run by a number of groups with varying initial assumptions and different parameter choices. The models, because of their varying complexity, could also make use of different levels of data supplied. The first results from this inter-comparison project will be looked at in more depth in the context of these JULES-based models. Their relative performance will be analysed looking at why they performed the way they did, including any implications for wider applications. Is more complicated necessarily better?