4种再分析资料在中国区域的适用性研究进展

A review on applicability evaluation of four reanalysis datasets in China

根据NCEP/NCAR、NCEP/DOE、ERA-40和JRA-25共4种比较常用的再分析资料在中国区域的适用性研究作了概述。结果表明:4种资料既呈现出一定的共性,又在不同区域、不同时间尺度上差异显著;再分析资料的可信度普遍表现为在东部地区好于西部地区,低纬地区好于高纬地区,这可能与中国地面气象站点"东密西疏"有关;1979年前的再分析资料存在较大的不确定性,因此在应用该时段NCEP/NCAR资料研究长期气候变化研究时需要谨慎;再分析资料的不同要素在不同时间、不同地域的适用性不同,因此应分区域、分要素和分季节选择合适的资料。从不同角度探讨了再分析资料的优缺点及在中国区域的适用性,旨在为中国区域气候变化研究选用再分析资料提供借鉴和参考。

The applicability of four reanalysis datasets in regional climate change research in China are reappraised and summarized,including NCEP/NCAR dataset,NCEP/DOE dataset,ERA-40 dataset and JRA-25 dataset.The results indicate that four datasets are of some commonness and also of discrepancies in different region and different time scales.Probably due to the distribution features of meteorological stations in China,namely,dense in the eastern China and sparse in the western China,the reliability of the reanalysis datasets is generally better in the eastern than in the western China,and greater in low latitude area than in high latitude area.The reanalysis datasets have the greater uncertainty before 1979,so it should be more cautions to use the NCEP/NCAR reanalysis dataset of this period,especially for the study of long-term climate change.The applicability of different variables of reanalysis datasets is different at different time scales and areas,so the optimum dataset should be selected based on area,element and season.Finally,merit and shortage of reanalysis datasets and applicability in China are summarized.This study could provide references for choosing reanalysis datasets of the regional climate change research.