130年来全球气温变化的模拟

本文利用海－气耦合的能量平衡模式研究了全球平均气温的变化。在对130年来全球气温变化的模拟研究中，比较全面地考虑了各种辐射强迫因子。此外，对于厄尼诺－南方涛动对全球平均温度的贡献也做了模式估计。数值模拟的全球温度序列与观测序列的相关系数达0.884，可解释77.8％的温度变化，并反映出温度的年际和年代际变化的特征，这可能是目前国内外同类工作的最佳结果。

SIMULATION OF GLOBAL TEMPERATURE CHANGES DURING THE LAST CENTURY

An energy -balance /upwelling-diffusion climate model was used to simulate the global temperature changes from 1861 to 1990. The atmospheric part of the model is essentially a zero-dimension one, in which the relationship between the temperature and the altitude, latitude and longitude was not considered. This model was coupled with a simple ocean model to include the heat flux through the upwelling and downwelling of oceanic circulation, as well as the heat exchanges between the polar and nor -polar regions.Impact of three most commonly cited external forcing factors, of climatic change including solar activity, volcanism and greenhouse effect were considered.Representativeness and quality of forcing factor data are critical to the simulation.Although there were observation data of the solar forcing about 100 years ago,the reliability of such data is questionable. The trustworthy observation appeared only after the satellite observation was available in 1970s. Therefore, some kinds of other series related to the solar forcing changes, instead of the forcing series itself, must be used to estimate the contribution of solar forcing on the climate changes during the last century. The envelope of the 11-yr sunspots cycle series was considered as a suitable indicator of solar radiation variability. It was transformed into forcing series based on recent radiation observation of satellite. The influence of the volcanism on the climate is very complicated, which varies with different eruption altitudes, intensity and seasons, etc. The evaluation of its influence is still controversial. A new ice-core volcanic index was chosen as a reliable estimate of volcanic aerosols loading in the atmosphere. The index was first changed into a series of stratospheric aerosol optical depth, and then to forcing series. Besides the greenhouse gas, the troposphere aerosol contributes to the climate changes through influencing the outgoing forcing directly. In addition, the aerosol changes the outgoing forcing indirectly by affecting the forming of clouds. The estimation of IPCC on greenhouse gas forcing was used in this paper, including the effects of the troposphere aerosol.The model was pre-integrated for 100 years with a colder initial condition to consider the influence of colder ocean before 1850. Then the model was run from 1850 - 1990 forced by the external forcing factors outlined above. The simulated temperature anomalies were compared with the observed series of Jones. If only greenhouse forcing is considered, the best fit occurs when △T2x=2.5℃ with the correlation coefficient of 0.817. This simulation captures the trend of the climate change but it is unable to reflect the changes on the decade time scale. If the solar forcing is considered alone, the best fit occurs at △T2x=3.5℃ with correlation coefficient of 0.841.This simulation describes some characteristics on decade time scale. If the volcanic forcing is considered alone, the best fit occurs when △T2x=14.7℃ with correlation coefficient of 0.761. Obviously, this climate sensitivity is far from the reality. Simulated series was closely correlated with observed one, with correlation coefficient 0.861 and explained variance 71.2% （1861~1990）. The main characteristics of temperature changes were successfully captured.It was found that the differences between the model and observed series closely correlated with the SOI index. In order to evaluate the contribution of ENSO on global temperature changes in model, a "ENSO Forcing", which was transformed from SOI index was introduced to run the model. A better result was obtained. Correlation coefficient and explained variance increased to 0.884 and 77.8% respectively. Finally,some remarkable details of climatic changes were simulated properly.In summary, these model results provide circumstantial support for the viewpoint that the three external forcing were the main causes of global climatic changes during the last century. Anthropogenic effects played a most important role in the warming of this century. The solar activity has