On the validation of the atmospheric model REMO with ISCCP data and precipitation measurements using simple statistics

The regional atmospheric model REMO is used to study the energy and water exchange between surface and atmosphere over the Baltic Sea and its catchment area. As a prerequisite for such studies, the model has to be validated. A major part of such a validation is the comparison of simulation results with observational data. In this study the DX product of the International Cloud Climatology Project (ISCCP) and precipitation measurements from 7775 rain gauge stations within the model domain are used for comparisons with the simulated cloud cover and precipitation fields, respectively. The observations are available in this high spatiotemporal resolution for June 1993. To quantify the comparisons of means, variability, and patterns of the data fields simple statistics are used and the significance of the results is determined with resampling methods (Pool Permutation Procedure and Bootstrap-t). The conclusion is that simulated and observed means of the fields are not different at the 5% significance level. The determined variability of the fields is also in good agreement except the space variability in cloud cover. Time mean and anomaly patterns are in good coincidence in case of the comparisons of cloud cover fields, but in reduced coincidence in case of precipitation.