The large-aperture scintillometer (LAS) has been widely used in the estimation of sensible heat fluxes (H) on various land surfaces, but they are seldom used in deserts with dune topographies. Here, an LAS was deployed in the Taklimakan Desert for about two weeks to investigate its ability to estimate H over the dune topography in the desert and its impact on the surface energy balance. We estimated the LAS and eddy covariance (EC) fluxes using standard methods, as well as H directly calculated by the EC system via a spectral fitting method. We conducted a series of sensitivity tests to investigate the scintillometer-based heat flux estimation uncertainties by considering surface and meteorological parameters and surface-layer similarity structure functions. In addition, the imbalance problem in the surface energy budget was examined using the measurements. Desert areas are different from other land surfaces in that they are characterized by a high sensible heat flux. It was found that the LAS had good performance in the Taklimakan Desert and could capture more low-frequency turbulence. Also, the spectral fitting method used on the data obtained with the EC system could capture more low-frequency turbulence compared to the direct calculations made by the EC system. The H values obtained by the LAS (H_LAS) were overestimated by about 11.6% relative to those measured by the EC system (H_EC), and the H_EC values obtained by the spectral fitting method were overestimated by about 12.1% relative to them being directly calculated by the EC system. Large and dispersed values of H_LAS/H_EC appeared with smaller values of r_wT (the correlation coefficient) (i.e., 0.1–0.3), and the large ratio of H_LAS/H_EC might be related to a predominance of low-frequency motions in stable stratification. However, the H values estimated by the LAS had great uncertainties in the case of high wind speeds and weak winds at night. The main source of uncertainty in the estimation of H by the LAS was the use of the different surface parameters (e.g., the Bowen ratio, roughness length, and LAS effective height) and the different forms of f_T(ζ) from the Monin–Obukhov similarity theory (MOST). Different from the flat surfaces in desert areas, dune topography affected the use of f_T(ζ) of MOST by 37%. MOST can improve the estimation of H, and then improve the calculation of the surface energy balance ratio (EBR).

大口径闪烁仪（LAS）已广泛应用于各种地表显热通量（ H ）的估算，但很少用于沙丘地形的沙漠。在这里，LAS 在塔克拉玛干沙漠部署了大约两周，以研究其估算沙漠沙丘地形H的能力及其对地表能量平衡的影响。我们使用标准方法估计了 LAS 和涡度协方差 (EC) 通量，以及HEC系统通过光谱拟合方法直接计算。我们进行了一系列敏感性测试，通过考虑地表和气象参数以及表层相似结构函数来研究基于闪烁计的热通量估计不确定性。此外，使用测量结果检查了表面能量收支的不平衡问题。沙漠地区与其他陆地表面的不同之处在于它们具有高感热通量的特点。发现LAS在塔克拉玛干沙漠中表现良好，可以捕捉到更多的低频湍流。此外，与 EC 系统进行的直接计算相比，对 EC 系统获得的数据使用的光谱拟合方法可以捕获更多的低频湍流。H _LAS ( H _LAS ) 得到的值相对于 EC 系统 ( H _EC ) 测量的值高估了约 11.6%，而通过光谱拟合方法获得的H _EC值相对于直接高估了约 12.1%由 EC 系统计算。H _LAS / H _EC值较大且分散，而r _wT （相关系数）值较小（即 0.1-0.3），H _LAS / H _EC的比值较大可能与低频占优势有关稳定分层的运动。但是，那LAS 估算的H值在夜间高风速和弱风的情况下具有很大的不确定性。LAS估计H的不确定性的主要来源是使用不同的表面参数（例如，Bowen 比、粗糙度长度和 LAS 有效高度）和来自 Monin–的不同形式的f _T ( ζ )奥布霍夫相似性理论（MOST）。与沙漠地区的平坦表面不同，沙丘地形对MOST的f _T ( ζ )的使用影响了37%。MOST 可以改进H的估计，进而改进表面能平衡比 (EBR) 的计算。