General Information
| HIRHAM | |
| Equations | hydrostatic; prognostic equations for u, v, T, q, qw, ps; diagnostic equations for ω, Φ. |
| Physical parameterizations | radiation, land surface processes, sea surface sea-ice processes, vertical diffusion (PBL), gravity wave drag, cumulus convection, large-scale condensation. |
| Grid | Arakawa-C; horizontal resol. 0.5° (50 km) or 0.25° (25 km); 19-36 unequally spaced vertical levels (hybrid σ-p). |
| Timing | Time step: 300 sec, semi-implicit leapfrog |
| Boundary conditions | Lateral: ECMWF or NCEP (re-)analyses or GCM (updated every 6h) Lower: ECMWF or SSMI/AVHRR or ocean-ice model (updated daily or every 6h). |
Acknowledgements and Detailed Information
The employed regional climate model is called HIRHAM and has been developed by Christensen and van Meijgaard (1992) and improved by Christensen et al. (1996). The adiabatic formulation is based on the limited area model HIRLAM (Machenhauer,1988, Gustafsson, 1993). The HIRLAM system was developed by the HIRLAM project group, a cooperative project of the national weather services in Denmark, Finland, Iceland, Ireland, the Netherlands, Norway, Sweden and Spain (hirlam.org).
HIRHAM uses the physical parameterization package of the general circulation model ECHAM (Roeckner et al., 1992, 1996).Physical parameterizations include: radiation, cumulus convection,stratiform clouds, land surface processes, hydrology, sea surface-, sea ice processes, planetary boundary layer and gravity wave drag (see also ECHAM3 or ECHAM4).
Orography with ice coverage used by HIRHAM