CHRM's parent model is DWD High Resolution Model (HRM) version 1.6. The HRM user's guide (Majewski 1999) is available on this site. Compared with HRM, CHRM basically comprises extensions to model I/O meant to handle very long data streams and extra variables, some special model configurations and settings (e.g. the soil layers distribution), a non-standard SVATS (TERRA, adapted from Dickinson (1984) and Jacobsen and Heise (1982)) and special utilities to handle climate data pre- and post-processing, including remotely sensed surface boundary conditions, such as the ISLSCP (Sellers et al. 1994) physiography data.