Chin J Plan Ecolo ›› 2002, Vol. 26 ›› Issue (6): 717-738.

• Research Articles • Previous Articles     Next Articles

The Characteristics of Budget of Radiation and Energy as Well Microclimate of Dunhuang Oasis on a Typical Clear Day In Summer

Zhang Qiang and Zhou Yi   

  • Published:2002-06-10
  • Contact: Zhang Qiang

Abstract: Utilizing the data of the intensive observation period (May-June 2000) in Dunhuang oasis of Dunhuang land-surface process field experiment that belongs to “Land-atmosphere Interactive Field Experiment over Arid Region of Northwest China”, the radiation budget, energy balance and microclimate at surface in Dunhuang oasis are analyzed systemically. It is found that, (a) the short-wave irradiance at surface in Dunhuang oasis is very high and can reach 1 038.1 w·m-2, (b) the surface net radiation can exceed 600 w·m-2, (c) the daily-integral values of sensible heat flux, latent heat flux and soil heat flux are in same order of magnitude, and (d) soil heat flux is larger than latent heat flux and is almost in same order of magnitude, in the partition of surface energy. The daily-integrated values of the short-wave irradiance, downward long-wave, upward long-wave and reflection radiation over Dunhuang oasis are 31.17, -36.15, 27.51 and -8.08 MJ·m-2·d-1, respectively. The daily integration of the net radiation is 14.53 MJ·m-2·d-1, and accounts for about 50% of that of the short-wave irradiance. The daily-integrated values of the sensible heat, the latent heat and the soil heat flux over Dunhuang oasis are respectively 4.04, 4.31 and 2.02 MJ·m-2·d-1 which account respectively for 27.7 %, 30.00% and 14.0 % of the net radiation. The residue of energy budget arrives at 28.7%. The surface albedo of oasis is always evidently bigger than that of Gobi desert except for noon when the surface albedo of oasis is evidently bigger than that of Gobi desert. The Bowen ratio over oasis is within 1-2, which is larger than that over desert (or Gobi). The considerable deficit of surface energy budget found in Dunhuang oasis, maybe the result of local thermodynamic circulation caused by surface thermodynamic differencce between oasis and desert nearby.