地表温度时空差异对温室效应影响的误差分析

Error Analysis of the Influence of Surface Temperature Spatiotemporal Difference on Greenhouse Effect

针对目前温室气体对全球变暖的影响研究中,大都将地表温度处理为单一的平均温度的现状,在分析全球地表温度时空分布特点的基础上,分别采用将其作均一化处理以及时空积分两种不同的方法,对CO2,CH4及N2O的辐射强迫进行了计算,并预测了未来100年内CO2与CH4辐射强迫的变化情况.结果表明:CO2辐射强迫受计算方法影响最大,两种方法计算所得到的绝对差值达到了0.12W/m2,相当于6%的偏差,而且随着其浓度的不断加大,偏差还会明显增加;但是对于以CH4为首的微量温室气体,即使浓度出现大幅增加,地表温度的时空差异对其辐射强迫也不会产生显著影响;目前,CH4所产生的辐射强迫大约已经占到CO2的25%,如果能够将CH4的年浓度增长控制在1μL/m3的水平上,其100年后的辐射强迫则仅为CO2的11%,从而显著缓解由于CO2浓度持续上升对全球变暖所施加的巨大压力.

Surface temperature is usually treated as a single mean value in most of the current global warming research. In response to this situation,based on the analysis of surface temperature spatiotemporal distribution characteristic, the radiative forcings of CO2, CH4 and so on were calculated and predicted by two ways. by the averaged surface temperature and by its spatiotemporal integration according to its spatiotemporal difference respectively. The results show that the radiative forcing of CO2 is affected by computation method most, with the absolute difference of the two methods of 0. 12 W/m^2, which is equivalent to 6% deviation. What＇ s more, the deviation will increase further with the increase of CO2 atmospheric concentration. As far as trace greenhouse gases such as CH4 and so on are concerned, even if the concentrations increase substantially, the spatiotemporal difference will not affect their radiative forcings markedly. The radiative forcing of CH4 is about 25% of that of CO2 at present, but the yearly increasing rate of CH4＇s radiative forcing is lower than that of CO2 greatly,so if the concentration growth of CH4 can be controlled within 1μL/m^3, CH4 ＇s radiative forcing will be almost invariable with time, and will only amount to 11% of that of CO2 after 100 years.