CP-2156 Life In The Universe

Figure 3. Global mean climatic sensitivity and stability of a zonally averaged energy balance climate model as a function of the strength of two radiation-temperature feedbacks.

Figure 3. Global mean climatic sensitivity and stability of a zonally averaged energy balance climate model as a function of the strength of two radiation-temperature feedbacks. (1) surface-temperature/planetary-albedo coupling and (2) surface-temperature/outgoing-infrared coupling. Global stability is defined as the percentage decrease in solar constant (from the present value) required to bring the edge of permanent ice to the equator. Local stability (or sensitivity) is proportional to the slope of the lines at the point of no change in solar constant (i.e., the global climatic sensitivity to small perturbations in solar constant). The values of B are plausible coefficients used in the empirical formula for outgoing infrared, mathematical symbol = A + BT (see fig. 1). f is the albedo-temperature coefficient for Sellers' (1969) planetary albedo parameterization. (Of the two values given, f = 0.004 is now thought to give a better simulation, although the validity of the parameterization for climatic change experiments is questionable.) Larger values of B (or f) indicate a stronger dependence of outgoing infrared irradiance (or planetary albedo) on surface temperature. Note that these plausible values of the parameters generate a wide range of climatic sensitivities. (Source: Warren and Schneider, 1979).

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