The Inter-CSE Transferability Study (ICTS) makes use of the CEOP data archive and contributes to the transferability working group (TWG) within the GEWEX Hydrological Panel (GHP). In the ITCS regional models from different Continental Scale Experiments (CSEs) will be transferred from their “home” CSE to other CSEs involved in GEWEX. The models will be initialized and forced at their boundaries by several state of the art Global Circulation Models (GCMs). At http://www.joss.ucar.edu/ghp/ceopdm/model/model.html one can find a list of global analyses data and associated data centres. In the first step data from global NCEP re-analysis will be used. Later other global data sets from the CEOP model data archive will be taken into account. For evaluation CEOP data from the CEOP reference site data archive and the CEOP satellite data archive will be considered. Main emphasis is on the energy and water cycle components. We will present initial results from simulations using three regional models with 50-km resolution, driven by NCEP re-analysis. The main focus will be on simulation domains covering North American and European CSEs. This study contributes to type 2 (“Home-based” global model; Embedded Regional Model Comparative Evaluation with “Home-based” Regional Model Output during CEOP plus CEOP Validation Data) and type 4 (Regional Model embedded in different global models to evaluate the effects of initial and boundary conditions from the different global models) of the transferability studies defined in CEOP. There are three major benefits of this study within WESP (Water and Energy Simulation and Prediction): • It is an example for application of CEOP data (model data, satellite data, and reference site data). • It fulfills the requirement of transferring regional models to other regions. • It contributes to water and energy budget studies.

Presently three centers (ECPC, GKSS, and Iowa State University) co-operate in ICTS. They participate with the regional spectral model (RSM), the climate version of the Lokalmodell (CLM), and the Regional Climate Model (RegCM3), respectively. With the expertise of regional modelers from each CSE currently five areas has been defined: two areas in North America for the CSE’s GAPP and MAGS, one in South America covering LBA and LaPlata, one in Europe (BALTEX), one in Australia (MDB), and one in Africa (AMMA).