CLIMBER-2: a climate system model of intermediate complexity. Part I: model description and performance for present climate

A 2.5-dimensional climate system model of intermediate complexity CLIMBER-2 and its performance for present climate conditions are presented. The mode l consists of modules describing atmosphere. ocean, sea ice, land surface p rocesses, terrestrial vegetation cover, and global carbon cycle. The module s interact through the fluxes of momentum, energy, water and carbon. The mo del has a coarse spatial resolution, nevertheless capturing the major featu res of the Earth's geography. The model describes temporal variability of t he system on seasonal and longer time scales. Due to the fact that the mode l does not employ flux adjustments and has a fast turnaround time, it can b e used to study climates significantly different from the present one and t o perform long-term (multimillennia) simulations. The comparison of the mod el results with present climate data show that the model successfully descr ibes the seasonal variability of a large set of characteristics of the clim ate system, including radiative balance, temperature, precipitation, ocean circulation and cryosphere.