Atmospheres and Oceans on Computers: Fundamentals Lars Petter Røed †,⋆,‡ † Research and Development Department, Norwegian Meteorological Institute, Postboks 43 Blin- dern, 0313 Oslo, Norge. ⋆ Department of Geosciences, Section Meteorology and Oceanography, University of Oslo, P. O. Box 1022 Blindern, 0315 Oslo, Norway ‡ E-mail: larspr@met.no Date printed: October 20, 2015