PROGRESS IN GEOGRAPHY ›› 2012, Vol. 31 ›› Issue (11): 1443-1451.doi: 10.11820/dlkxjz.2012.11.004

• Original Articles • Previous Articles     Next Articles

Comparative Analysis of Radiation and Energy Budget over Badain Jaran Desert on Clear and Cloudy Days in Summer

LI Jiangang1,2, AO Yinhuan1, LI Zhaoguo1,2   

  1. 1. Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China;
    2. Graduate University of Chinese Academy of Sciences,Beijing 100049, China
  • Received:2012-04-01 Revised:2012-07-01 Online:2012-11-25 Published:2012-11-25

Abstract: Based on the study of land-atmosphere interactions in Badain Jaran desert in the summer of 2009, this paper presents a comparative analysis of diurnal variations of surface radiation, energy budget and soil temperature under different synoptic conditions. As shown in the results: (1) In Badain Jaran desert, global radiation, surface reflection radiation, surface long-wave radiation, effective radiation and net radiation are all greater on typical clear days than those on typical cloudy days. However, atmospheric long-wave radiation is greater on cloudy days. Under both weather conditions, daily integral value of net radiation is 1/3 of global radiation. (2) The distribution of day-time surface albedo on clear days takes a U shape with an average value of 0.32, while it is relatively flat on cloudy days with an average value of 0.29. (3) The sensible heat transfer is the major component of the surface energy budget. On clear days and cloudy days, Bowen ratio (the ratio of sensible heat to latent heat) is 4.55 and 1.16 respectively, and imbalance energy accounts for 20% and 30% of net energy respectively. (4) The effective energy is negative in day time and positive in night time on clear days, and is positive all the time on cloudy days. Turbulent energy is always positive. The average EBR (energy budget ratio) is 0.68 on clear days and 0.76 on cloudy days. (5) The diurnal variations of soil temperature decrease as the depth changes from 5 to 10 cm (Δ15.7℃ vs. Δ9.4℃). In 20~40 cm depth range, there is almost no diurnal variation. Under both weather conditions, soil heat flux shows greatest diurnal variations at 5 cm depth and very little at 20 cm depth.

Key words: Badain Jaran, desert, energy budget, radiation