TY - RPRT AU - E. Källén CY - Shinfield Park, Reading DA - 07/1980 LA - eng M1 - 19 M3 - Technical Report PB - ECMWF PP - Shinfield Park, Reading PY - 1980 EP - 39 TI - A low order barotropic model on the sphere with orographic and Newtonian forcing ER -