Climate patterns derived from chinese proxy precipitation records: An evaluation of the station networks and statistical techniques

The 510‐year, 120‐stalion proxy precipitation records published by the State Meteorological Administration of the People's Republic of China were used to study the large‐scale climate patterns, including the climate regions and interregional relationships. In this paper, we present a study of the sensitivity of the climate patterns of recent years (1950–1979) to choice of stations and statistical techniques. First, the original highly inhomogeneous 120‐station network is reduced to a quasi‐uniform network comprising 93 stations. Next, based on the reduced network, two new networks arc derived‐a47‐station network with the same spatial domain and a 29‐station network with half the domain. The climate patterns for these station networks are compared by use of two different statistical procedures, principal component analysis/cluster analysis and factor analysis with orthogonal and oblique rotations. It is found that the climate patterns remain similar when the density and domain of the 120‐station network are systematically reduced. It is also found that similar climate patterns are obtained using either of the chosen statistical techniques, although factor analysis appears to be more sensitive to changes in the network than principal component/cluster analysis. Examination of measurement data also reveals large‐scale climate patterns similar to those derived from the proxy data. Finally, the climate patterns are shown to be consistent with geophysical factors.