| Discrepancy and Applicability of Various Similarity Functions in Flux Calculations Under Stable Conditions |
| |
| 作者姓名： | GUO Xiaofeng ZHANG Hongsheng CAI Xuhui KANG Ling LI Wanbiao DU Jinlin |
| |
| 作者单位： | [1]Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 100871 [2]Department of Environmental Sciences, Peking University, Beijing 100871 |
| |
| 基金项目： | The current research was jointly funded by the National Natural Science Foundation of China under Grant Nos. 40175005, 40275006, and 40233030, as well as the Natural Science Foundation of Beijing under Grant No.8052012. |
| |
| 摘 要： | Based on data obtained during the Hualhe River Basin Experiment （HUBEX） in 1999, this study intends to detect the quantitative discrepancies in the momentum （τ0）, sensible heat （H0） and latent heat （E0） fluxes among six sets of similarity functions with the aerodynamic method. It also aims to clarify the applicability of the functions under stable conditions. The relative discrepancy was studied with the normalized transfer coefficients for τ0, H0 and E0, namely CD, CH and CQ, respectively. Except for one set of functions that adopted a rather small von Kármán＇s constant （0.365）, the relative discrepancy in τ0 among the other functions was less than 10%, while that in H0（E0） sometimes reached 25% when the bulk Richardson number （R/B） was less than 0.07. The absolute discrepancy in the fluxes was studied with statistical computations. Among the six sets of functions, the discrepancy in τ0, H0 and E0 sometimes reached 0.03 kg m^-1 s^-2, 4 W m^-2 and 10 W m^-2, respectively, and the discrepancy in the energy balance ratio sometimes exceeded 0.1. Furthermore, when RiB exceeded the critical value （Ric） for a specific set of functions, no fluxes could be derived with the functions. It is therefore suggested that RiB be compared with Ric before computing the fluxes if RiB is less than Ric. Finally, two sets of nonlinear similarity functions are recommended, due to their unlimited applicability in terms of RiB.
|
| 关 键 词： | 空气动力学 湍流通量 相似函数 能量平衡 |
| 收稿时间： | 13 July 2006 |
| 修稿时间： | 2006-07-132006-11-07 |
Discrepancy and Applicability of Various Similarity Functions
in Flux Calculations Under Stable Conditions |
| |
| GUO Xiaofeng,ZHANG Hongsheng,CAI Xuhui,KANG Ling,LI Wanbiao,DU Jinlin.Discrepancy and Applicability of Various Similarity Functions in Flux Calculations Under Stable Conditions[J].Advances in Atmospheric Sciences,2007,24(4):644-654. |
| |
| Authors: | GUO Xiaofeng ZHANG Hongsheng CAI Xuhui KANG Ling LI Wanbiao and DU Jinlin |
| |
| Institution: | Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 100871,Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 100871,Department of Environmental Sciences, Peking University, Beijing 100871,Department of Environmental Sciences, Peking University, Beijing 100871,Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 100871,Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 100871 |
| |
| Abstract: | Based on data obtained during the Huaihe River Basin Experiment (HUBEX) in 1999, this study intends to detect the quantitative
discrepancies in the momentum (τ
o), sensible heat (H
o) and latent heat (E
o) fluxes among six sets of similarity functions with the aerodynamic method. It also aims to clarify the applicability of
the functions under stable conditions. The relative discrepancy was studied with the normalized transfer coefficients for
τ
o, H
o and E
o, namely C
D,C
H and C
Q, respectively. Except for one set of functions that adopted a rather small von Kármán’s constant (0.365), the relative discrepancy
in τ
o among the other functions was less than 10%, while that in H
o(E
o) sometimes reached 25% when the bulk Richardson number (Ri
B) was less than 0.07. The absolute discrepancy in the fluxes was studied with statistical computations. Among the six sets
of functions, the discrepancy in τ
o
H
o and E
o sometimes reached 0.03 kg m−1 s−2, 4W m−2 and 10 W m−2, respectively, and the discrepancy in the energy balance ratio sometimes exceeded 0.1. Furthermore, when Ri
B exceeded the critical value (Ri
C) for a specific set of functions, no fluxes could be derived with the functions. It is therefore suggested that Ri
B be compared with Ri
C before computing the fluxes if Ri
B is less than Ri
C. Finally, two sets of nonlinear similarity functions are recommended, due to their unlimited applicability in terms of Ri
B. |
| |
| Keywords: | aerodynamic method turbulent flux surface layer similarity function energy balance |
| 本文献已被 CNKI 维普 SpringerLink 等数据库收录！ |
| 点击此处可从《大气科学进展》浏览原始摘要信息 |
| 点击此处可从《大气科学进展》下载免费的PDF全文 |
|
