The Study of Recent Climatic Fluctuation in the Maowusu Sand Region

Based on the meteorological data of seventeen stations in the Maowusu sand region in the recent 40 years, we investigated climatic characteristics of radiation, heat, precipitation and wind sand and revealed that spring is the most severe season of desertification in the region. We also discussed in detail climatic evolution tendencies of various factors related to desertification processes. The power spectra were analysed for the time series (1955—1988) of annual precipitation and aridity degree in the four stations of Etoke, Dongsheng, Yanchi and Yulin, respectively. The pronounced oscillation periods are quasi-triennial and eight to nine years. The quasi-triennial vibration may be associated with the periodic variations of SST, subtropical high, temperature of Tibetan Plateau and cold air activity of the northern hemisphere