Modeling the climate Chapter 15 • Computer models project future climate. • Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice.
Two Box model Includes surface – atmosphere energy flows 2 3 4 1 Atmosphere 5 6 7 8 9 Surface 5 = Sunlight absorbed by the surface 6 = Sunlight reflected by the surface 7 = convection and evaporation 8 = infrared emitted upward from surface 9 = infrared emitted downward from the atmosphere 1 = Incident solar energy 2 = sunlight reflected from atmosphere 3 = infrared transmitted through atmosphere to space 4 = infrared emitted by atmosphere to space
One-dimensional model • Temperature varies with the altitude. • The atmosphere was represented with many boxes. • So the one dimensional model accounts for different altitudes.
Two-Dimensional models • Two-dimensional model typically accounts for different latitude as well as altitudes. • These models can simulate seasonal changes and atmospheric circulations from tropics to poles
Three-dimensional models • Three dimensional model have all. • They divide earth-atmosphere system into boxes whose position vary with latitude, longitude, and altitude.
General Climate (Circulation)Model-(GCMs) • The large-scale models which includes ocean circulation are called GCMs.
Atmosphere -Ocean General Circulation Model (AOGCM) • A model that couples atmosphere and ocean is called AOGCM. • These are the largest and most comprehensive climate models
Time-dependent model • These model consider flows of energy also advance the model system forward in time. • Time dependent model not only project future climate but they also show the path from present to future.