Acta Geographica Sinica ›› 1999, Vol. 54 ›› Issue (4): 309-317.doi: 10.11821/xb199904003

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Monthly Mean Surface Albedo Estimated From NCEP/NCAR Reanalysis Radiation Data

ZHANG Qiong, QIAN Yong fu   

  1. Department of Atmospheric Sciences, Nanjing University, Nanjing 210093
  • Received:1998-03-18 Revised:1998-06-27 Online:1999-07-15 Published:1999-07-15
  • Supported by:
    National Natural Science Foundation of China,No.49635190

Abstract: The 17 years mean (1979~1995) NCEP/NCAR reanalysis radiation data are used to estimate the global monthly mean surface albedo. For clear sky conditions, the monthly mean surface albedo can be obtained by the ration of monthly mean reflected radiant flux and monthly mean total radiant flux at surface, and a correction is applied which takes account of the effect of solar zenith angle. The results show that the seasonal cycle and the spatial distribution of global surface albedo are correspondent to the characteristics and variations of the earth’s different underlying surface. The zonally averaged surface albedo shows an apparent annual variation. A comparison of the results of present method with other studies indicates that the values of sea surface albedo at high latitudes in this work tend to be slightly higher than the others. While the distribution of surface albedo in other regions are basically consistent to the others. The surface albedo in China also well represents the characteristics and seasonal cycle of complex underlying surface. Compared to the other similar works carried by Chinese scientists, the time and spatial distribution are accordant but the values in some regions are slightly higher. Verified by observation data of Qinghai Xizang (Tibetan) Plateau Meteorological Scientific Experiment in 1979, it is found that the surface albedo in the Qinghai Xizang (Tibetan) Plateau region obtained from the NCEP/NCAR data is closer to the observation data than the others. From the above results, it is suggested that the global monthly mean albedo estimated from the NCEP/NCAR can be applied into the global climate model, further correction for the albedo will depend on the sensitivity numerical experiment of the climate model.

Key words: monthly mean surface albedo, NCEP/NCAR reanalysis data, time and spatial distribution, annual variation

CLC Number: 

  • P422.15