This paper describes the development and assessment of global 0.5° near-surface atmospheric data from 1948 to 2006 at daily (for precipitation, snowfall, and specific humidity) to 3-hourly (for temperature, shortwave radiation, and longwave radiation) time scales, which can be used to drive land surface models. Using newly available monthly precipitation and temperature data extending to recent years, the variables were created by statistical methods, the parameters of which were obtained from available daily to 3-hourly observations. The daily precipitation developed in this paper produces reasonable numbers of precipitation days and heavy precipitation days, different from previous long-term meteorological data sets based on reanalysis. Together with its relatively high spatial resolution (0.5°) and availability of recent years, the newly obtained data may be preferred to other forcing data sets in case of hydrological and climate change studies, in particular if the study results are sensitive to daily variations in atmospheric conditions.
2008 Japan Society of Hydrology and Water Resources