中国物理B ›› 2014, Vol. 23 ›› Issue (2): 29201-029201.doi: 10.1088/1674-1056/23/2/029201

• GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS • 上一篇    下一篇

Improvement of surface flux calculation:A study based on measurements over alpine meadow in the eastern Tibet Plateau in summer

李森, 钟中   

  1. College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101, China
  • 收稿日期:2013-04-17 修回日期:2013-06-28 出版日期:2013-12-12 发布日期:2013-12-12
  • 基金资助:
    Project supported by the National Key Basic Research and Development Project of China (Grant Nos. 2011CB952002 and 2010CB428505) and the National Natural Science Foundation of China (Grant No. 41175090).

Improvement of surface flux calculation:A study based on measurements over alpine meadow in the eastern Tibet Plateau in summer

Li Sen (李森), Zhong Zhong (钟中)   

  1. College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101, China
  • Received:2013-04-17 Revised:2013-06-28 Online:2013-12-12 Published:2013-12-12
  • Contact: Zhong Zhong E-mail:zhong_zhong@yeah.net
  • About author:92.60.Kc; 92.60.hk; 47.27.T-; 47.27.te
  • Supported by:
    Project supported by the National Key Basic Research and Development Project of China (Grant Nos. 2011CB952002 and 2010CB428505) and the National Natural Science Foundation of China (Grant No. 41175090).

摘要: An improved flux-gradient relationship between momentum φm (ζ) and sensible heat φh (ζ) is obtained by the use of the observational data over an alpine meadow in the eastern Tibet Plateau, in Maqu of China during the period June to August, 2010. The empirical coefficients of Businger–Dyer type function for the cases of unstable and stable stratification are modified. Non-dimensional vertical gradients of wind and potential temperature are calculated by three fitting functions; that is, the log–linear, log–square, and log–cubic functions, respectively. It is found that the von Karman constant approaches 0.4025 and the Prandtl number is about 1.10 based on the measurements in near-neutral conditions, which are within reasonable range proposed in previous studies. The revised flux-gradient profile functions of -1/5 power law for momentum and -1/3 power law for sensible heat are best fitted in unstable stratification conditions. Meanwhile, 2/5 power law, instead of linear functions, is more appropriate in stable stratification cases for momentum and sensible heat. Compared with results from previous studies in which traditional functions are used, the momentum and sensible heat fluxes estimated by the revised profile functions in the current study are much closer to the observations for the unstable and stable stratification conditions.

关键词: Monine–, Obukhov similarity theory, flux-gradient relationship, Maqu experimental site, turbulent fluxes

Abstract: An improved flux-gradient relationship between momentum φm (ζ) and sensible heat φh (ζ) is obtained by the use of the observational data over an alpine meadow in the eastern Tibet Plateau, in Maqu of China during the period June to August, 2010. The empirical coefficients of Businger–Dyer type function for the cases of unstable and stable stratification are modified. Non-dimensional vertical gradients of wind and potential temperature are calculated by three fitting functions; that is, the log–linear, log–square, and log–cubic functions, respectively. It is found that the von Karman constant approaches 0.4025 and the Prandtl number is about 1.10 based on the measurements in near-neutral conditions, which are within reasonable range proposed in previous studies. The revised flux-gradient profile functions of -1/5 power law for momentum and -1/3 power law for sensible heat are best fitted in unstable stratification conditions. Meanwhile, 2/5 power law, instead of linear functions, is more appropriate in stable stratification cases for momentum and sensible heat. Compared with results from previous studies in which traditional functions are used, the momentum and sensible heat fluxes estimated by the revised profile functions in the current study are much closer to the observations for the unstable and stable stratification conditions.

Key words: Monine–Obukhov similarity theory, flux-gradient relationship, Maqu experimental site, turbulent fluxes

中图分类号:  (Land/atmosphere interactions)

  • 92.60.Kc
92.60.hk (Convection, turbulence, and diffusion) 47.27.T- (Turbulent transport processes) 47.27.te (Turbulent convective heat transfer)