HIROMB, an operational eddy-resolving model for the Baltic Sea

HIROMB is a 3-dimensional baroclinic model of the North Sea and the Baltic Sea, designed for daily operational use. The model is mainly developed by Eckhard Kleine at the German Federal Maritime and Hydrographic Agency (BSH) in Hamburg, Germany, and is based on a similar model, running in operational mode at that institution. The operational forecasts at SMHI starled already in 1995 with a daily 24-hour forecast and were later extended to 48 hours. The model is forced by SMHI's operational atmospheric model (HIRLAM), but also by river runoff from an operational hydrological model and wave radiation stress from a wind wave model. The present version of the model is set up on a nested grid, where a 12 nautical mile (nm) grid covers the whole area, while Skagerrak, Kattegat, the Belt Sea and the Baltic Sea are covered with a 1 nm grid. A parallelized version of the model has been developed and runs on a distributed memory parallel computer.