近32 a中亚地区气温时空格局分析

中亚地区生态环境脆弱，生态系统对于气候变化的响应非常敏感，但其气候变化的时空格局并不清楚。该区域气象站点分布稀疏、高精度气象数据缺乏，利用单一数据源研究气候变化具有极大的不确定性。因此，结合站点数据和再分析数据探索中亚五国气候变化时空格局具有重要的研究价值。选取31个气象站点数据（OBS）、CRU气象插值数据和CFSR、ERA-Interim和MERRA三套高精度的再分析数据，对中亚地区1980-2011年的年、四季气温的时空格局变化进行分析。研究结果表明：（1） 近32 a中亚年均气温显著升高，增温速率为0.36～0.47 ℃·（10 a）^-1，即过去的近32 a中亚地区平均气温升高1.15～1.50 ℃。（2）四季气温变化中春季的增温速率最快（0.71～0.93 ℃·（10 a）^-1），而冬季气温无显著性的变化。（3）中亚中部、南部、西南部、西部地区显著增温，尤其是在1990s后期至2000s前期经历了显著性地增温过程，而中亚其它地区气温无显著变化。

Temporal pattern analysis of air temperature change in Central Asia during 1980-2011

Ecology and environment of arid Central Asia is fragile and sensitive to climate change. However，its tempo-spatial pattern of climate change is uncertain. Owing to the sparse distribution of meteorological stations and the lack of high-precision meteorological data，using a single data source to study the regional climate change may introduce great uncertainty. Therefore，it is highly recommended to combine site observation meteorological data with reanalysis climate data to explore the tempo-spatial pattern of climate change in Central Asia. In this paper，data of 31 meteorological stations （OBS），the CRU meteorological interpolation data and three high-resolution reanalysis data：CFSR，ERA-Interim and MERRA are used to analyze the temporal changes of air temperature. The applicability of the CRU，CFSR，ERA-Interim and MERRA，in Central Asia were evaluated with the observed temperature data （OBS） during 1980-2011 from 31 meteorological stations with the correlation analysis，T-test and the method of least squares. The accuracies of the reanalysis datasets were quantified with absolute error （AE），correlation coeffic- ient （CC），mean absolute error （MAE） and root mean square error （RMSE）. The evaluation results showed that all the datasets can catch the annual and seasonal temperature change well （The CC value is 0.70 to 0.98）. These indicated that all the four datasets can be used to describe the temperature change of Central Asia，especially the temperature spatial pattern. For each dataset，the CRU and ERA-Interim had an underestimation for the air temperature of OBS and the underestimate range is -1.14 to -0.31 ℃. While the MERRA data had an overestimation for the OBS，the overestimate range is 0.09 to 2.03 ℃. In addition，there are best simulation results for the annual and winter temperature: the CC values are bigger than 0.9 and the MAE is -0.5 to 1.23 ℃. However，the summer simulation results were worse than spring，fall and winter: the CC values reached 0.7-0.84 and the MAE is -1.14 to 2.03 ℃. The temperature change results indicated as follows：（1） In the last 32 years，annual average air temperature has increased significantly by 0.36-0.47 ℃·（10 a）^-1，which means that has already rose 1.15-1.50 ℃ in Central Asia during the period；（2） Air temperature rise is the fastest 0.71-0.93 ℃·（10 a）^-1 in spring，but there is no obvious change in winter；（3） The middle，the south，the southwest and the west region of Central Asia has experienced significant warming process during the last 1990s to the early 2000s，while the air temperature of other parts in Central Asia has no obvious change.