Comparison of in situ station data and reanalysis data in winter and summer temperature in China

Abstract

ABSTRACT Variation of winter and summer temperature in China were discussed in detail by using EOF analysis and differences between the datasets derived from in situ stations of china meteorological data sharing service system and NECP/NCAR reanalysis, ERA40 reanalysis were compared in winter and summer temperatur e in China. Results showed that o 1) Winter temperature increases linearly with identical signs all over china exce pt the Tibetan plateau. It is colder than the normal before the late 1970s an d warmer since then, especially in 1990 s.2) Variation of summer temperature is complicated that it increases in north China but decreases in south to mid-lower reaches of Huangh e and the north of Jiangnan district ÷ 3) The values of NCEP/NCAR and ERA40 reanalysis data are commonly lower than the observations in winter and higher in summer; meanwhile, the change ranges of the reanalysis are closer to the observations’. The spatial and temporal features of winter temperature obtained from the reanalysis data are consistent with that of the observations, but for summer temp erature, the spatial and temporal features derived from the ERA40 are better than that of NCEP/NCAR. ERA40 can represent main variations of the summer temperature as the spatial distributions, linear trend and inter-decadal charac teristics, but the NCEP/NCAR dataset shows si gnificant differences from the observations for the spatial /temporal variations, the remarkable abrupt change around mid-1970s in NCEP/NCAR can not be seen in observations and in ERA40. Keywords: temperature e comparisone EOFe in situ station data e NCEP/NCARe ERA40