%0 Journal Article
%A Guo, Shuhai
%A Chen, Rensheng
%A Liu, Guohua
%A Han, Chuntan
%A Song, Yaoxuan
%A Liu, Junfeng
%A Yang, Yong
%A Liu, Zhangwen
%A Wang, Xiqiang
%A Liu, Xiaojiao
%A Wang, Lei
%A Zheng, Qin

%T Simple Parameterization of Aerodynamic Roughness Lengths and the Turbulent Heat Fluxes at the Top of Midlatitude August-One Glacier, Qilian Mountains, China
%D 2018
%J Journal of Geophysical Research: Atmospheres
%P 12,066-12,080
%V 123
%N 21
%@ 2169-897X
%R https://doi.org/10.1029/2018JD028875
%U https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD028875
%X Abstract The fluxes of sensible heat (H) and latent heat (LE), which are generally the important parts of the energy and mass balances over glacier surfaces, are widely quantified by the bulk method. However, due to the difficulty of determining the aerodynamic roughness length z0m in this method, H and LE values may still have large uncertainties with significant inaccuracy. To acquire reliable varying and intrinsic z0m values, new simpler parameterizations for z0m values at different ranges of the friction velocity u*b were fitted in this study. The method was implemented using the related meteorological data and glacial sublimation/condensation measured at the top of the August-one glacier (4817 m asl) in the Qilian Mountains from 1 July 2016 to 15 August 2017. The parameterization shows that z0m increased sharply when u*b exceeded 0.43 m/s (the approximate threshold value) and that the effect of snowdrift was slight for the hourly z0m values in the range 0.15 ≤ u*b ≤ 0.43 m/s, which could thus be used to calculate the daily z0m. During the wet period (1 July to 24 September 2016 and 5 May to 15 August 2017), the turbulent fluxes calculated by the bulk method showed that net radiation Rnet was the primary source of surface energy (60.7 w/m2), whereas during the dry period (25 September 2016 to 4 May 2017), the main heat sink was the positive H (28.5 w/m2) rather than the negative Rnet (−10.0 w/m2).