時間-空間スペクトル法によるエネルギー平衡気候モデル

Abstract

By using a globally or zonally averaged (so-called 0-dimensional or 1-dimensional) energybalance cliamte model based on a time-space spectral method, we examine effects of periodicforcing due to the change of incoming solar radiation to the multiplicity of the modelsolutions.In the 0- and 1-dimensional models for the forcing with such a period larger than l0 3years, we can obtain a middle solution besides the high and low extreme solutions continuingfrom the solutions for constant forcing models.In the above model an albedo-temperature feedback process is taken into consideration, and the effect of the lag-time between albedo and temperature to the solution is examined:A time-delay of the albedo affects the multiplicity of the solution so that the above-mentionedmiddle solution exists only in the range of strong periodic forcing.