Climatic Change Calculated by a Simple Heat Transfer Model at the Earth Surface

Abstract

Temperature variation due to fluctuation of solar radiation on the earth is calculated numerically by assuming a simple heat transfer model. If the amplitude of the change of the solar radiation is equal for various periods, the amplitude of short periodic temperature change becomes small by the effect of heat capacity of the sea water or the earth crust, but the amplitude of long periodic change (longer than about 1, 000∼10, 000 years) tends to a certain same value which is given by quasi-equilibrium state between the solar and the long wave radiation at the earth surface. It is found also, that if there is random variation of yearly solar radiation of about 0.5% in the standard deviation, 40∼80 year cyclic temperature change of about 1°C in amplitude will occur, which is comparable with the observed change of ten-year mean temperature.