球谐分析方法在全球温度场重建中的初步应用

A Preliminary Application of Spherical Harmonic Analysis in Global Temperature Field Reconstruction

球谐分析方法可用来分析球面上连续变化的量，本文尝试将这种方法应用于全球温度场重建中。基于所有代用资料站点上的1951—2010年时段器测数据，重建了全球温度的空间分布。经与器测资料比较发现，无论在站点密集还是稀疏的陆地区域重建结果都比较可信，但在没有站点分布的海洋区域重建结果较差。进一步研究发现，当站点在全球均匀分布时，只用40～50个站点重建的温度场就能反映空间上大尺度的温度变化，而用更多的站点重建时，则可以清晰地反映温度的区域性变化。

Spherical harmonic analysis method can be used to analyze the continuous variables on the surface of sphere. This paper attempted to apply this method to the reconstruction of the global temperature field. Based on instrumental data of all the stations where proxy records exist, we reconstructed the spatial patterns of global temperatures for the period from 1951 to 2010. The comparison between the reconstructed results and instrumental temperature data shows that the reconstructed temperature field is reliable on land areas no matter how dense or sparse the stations are distributed. But for marine areas where no stations are distributed, the results of reconstructed temperature field are poor. Further studies show that, when the stations is uniformly distributed on earth, the reconstructed temperature field using only 40-50 stations will be able to reflect the change of temperature on a large-scale, and changes of regional temperature can be clearly reflected when more stations are used in the reconstruction.