Turbulent transfer coefficient and roughness length in a high-altitude lake, Tibetan Plateau
Turbulent transfer coefficient and roughness length in a high-altitude lake, Tibetan Plateau
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DOI：
10.1007/s00704-015-1440-z
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发表时间：
2016-05
影响因子：
3.4
通讯作者：
Zhaoguo Li;S. Lyu;Lin Zhao;L. Wen;Yinhuan Ao;Shaoying Wang
中科院分区：
文献类型：
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作者：
Zhaoguo Li;S. Lyu;Lin Zhao;L. Wen;Yinhuan Ao;Shaoying Wang
在恩戈林湖上空观测到一个持续不稳定的大气边界层，这是由于水面温度高于上覆空气温度造成的。在此背景下，涡度相关通量数据收集Ngoring湖被用来分析的动量，热量和水分的传输系数和粗糙度长度的变化。结果进行了讨论，并与参数化方案在湖泊模式。阻力系数和动量粗糙度随风速的增大而迅速减小，在中等风速时达到最小值，然后随风速的进一步增大而缓慢增大。在弱风条件下，表面张力或小尺度毛细波变得更加重要，并增加表面粗糙度。在弱风条件下，标量粗糙度长度比远大于1，当风速超过4.0 m s−1时，标量粗糙度长度比减小到接近1的值。湖模式不能很好地再现的阻力系数，或动量粗糙度长度的变化，对风速在恩戈林湖，但它模拟的感热和潜热通量，作为互补的相反的错误的结果。
A persistent unstable atmospheric boundary layer was observed over Lake Ngoring, caused by higher temperature on the water surface compared with the overlying air. Against this background, the eddy covariance flux data collected from Lake Ngoring were used to analyse the variation of transfer coefficients and roughness lengths for momentum, heat and moisture. Results are discussed and compared with parameterization schemes in a lake model. The drag coefficient and momentum roughness length rapidly decreased with increasing wind velocity, reached a minimum value in the moderate wind velocity and then increased slowly as wind velocity increased further. Under weak wind conditions, the surface tension or small scale capillary wave becomes more important and increases the surface roughness. The scalar roughness length ratio was much larger than unity under weak wind conditions, and it decreased to values near unity as wind velocity exceeded 4.0 m s−1. The lake model could not reproduce well the variation of drag coefficient, or momentum roughness length, versus wind velocity in Lake Ngoring, but it did simulate well the sensible heat and latent heat fluxes, as a result of complementary opposite errors.