A Global Ocean-Atmosphere Climate Model. Part I. The Atmospheric Circulation

Abstract

Abstract A joint ocean-atmosphere model covering the entire globe has been constructed at the Geophysical Fluid Dynamics Laboratory (GFDL) of NOAA. This model differs from the earlier version of the joint model of Bryan and Manabe both in global domain and inclusion of realistic rather than idealized topography. This part of the paper describes the structure of the atmospheric portion of the joint model and discusses the atmospheric circulation and climate that emerges from the time integration of the model. The details of the oceanic part are given by Bryan et al. (1974), hereafter referred to as Part II. The atmospheric part of the model incorporates the primitive equations of motion in a spherical coordinate system. The numerical problems associated with the treatment of mountains are minimized by using the “sigma” coordinate system in which pressure, normalized by surface pressure, is the vertical coordinate. For vertical finite differencing, nine levels are chosen so as to represent the planetary bou...