Evaluation of the Korea Meteorological Administration Advanced Community Earth-System model (K-ACE)

Scientific community has been elaborating to better understand the observed climate and its variations, and to improve the capability for predicting future climate. Many modeling groups participating in the Coupled Model Inter-comparison Project (CMIP) have been working towards multi-model ensemble approach that have become a standard technique for projecting future climate and for assessing associated uncertainties to deal with intrinsic shortcomings of climate models. Within this context, the National Institute of Meteorological Sciences/Korea Meteorological Administration (NIMS/KMA) has developed the KMA Advanced Community Earth-system model (K-ACE) under KMA-Met Office collaboration for climate research. This paper provides general descriptions of the first generation K-ACE model including the coupling strategy, as well as preliminary evaluations of the model performance in mean climate fields. The first generation K-ACE model appears to capture the mean climatology and the inter-annual variability of the observed climate. Horizontal distributions and the variability of the surface and pressure-level variables agree well with observations with correlation coefficients of 0.88-0.99 and 0.69-0.99, respectively. Measured in terms of performance index between the observed and simulated fields, the K-ACE performance is comparable with those of 29 CMIP5 models. This study also identifies key weaknesses of the K-ACE in the present-day climate. Improving these deficiencies will be a topic of future studies. The NIMS/KMA will employ the K-ACE model to contribute to the CMIP6 experiment.