Jin Xiang, Song Xiaoquan, Yang Yawen, Wang Mian, Shao Shiyong, Zheng Haitao
Opt Express. 2022 Apr 11;30(8):13263-13277. doi: 10.1364/OE.455079.
Obtaining turbulence parameters in the marine atmospheric boundary layer (MABL) is limited by the observation environment and cost. Therefore, estimating based on the weather forecast model or combining the model output with limited observations is a more flexible choice. We conducted cruise observation experiments in the Bohai Sea, China, from May 17 to June 4, 2021. On the basis of the wind profile observed by the coherent Doppler lidar and the temperature, as well as pressure profiles output by the Weather Research and Forecasting (WRF) model, we implemented the Tatarskii turbulence model to estimate the refractive index structure constant 2 in the atmospheric boundary layer of the Bohai Sea under clear sky. The temporal and spatial variations of turbulence in the Bohai Sea atmospheric boundary layer are studied by combining the vertical velocity variance 2, skewness S and kurtosis K. The performance of simulated 2 and meteorological parameters in the WRF in the atmospheric boundary layer at the Bohai Sea is evaluated through the experimental measurements of UAV-borne (unmanned aerial vehicle) radiosonde and lidar. Finally, we give the model of the 2 variation with height in the atmospheric boundary layer at the Bohai Sea. The results show that WRF can better simulate 2 in most cases. The bias between the measured and simulated 2 is within one order of magnitude, and the root mean square error ( RMSE ) is within two orders of magnitude. Due to the potential uncertainty of the WRF, the RMSE between the measured and simulated wind speed is 4 ms to 6 ms, which is almost two times of the result in previous studies on the underlying land surface. The overall changes of 2 and 2 are similar when the turbulence is well mixed and developed, which shows the consistency in both of optical and dynamics turbulence. But this consistency is not absolute. The temperature difference between the sea surface and the atmosphere leads to the widespread existence of an inversion layer from the sea surface to hundreds of meters in the Bohai Sea. The suppression of the inversion layer weakens the near sea surface turbulence. There is an enhancement of turbulence intensity below the inversion layer and a decrease from the upper inversion layer to top of the boundary layer among the entire boundary layer, also, the position of the inflection point is determined by the height of top of the inversion layer. The main results of this study are the reference significance for further understanding the development and change characteristics of turbulence in the MABL.
在海洋大气边界层（MABL）中获取湍流参数受到观测环境和成本的限制。因此，基于天气预报模型进行估算或将模型输出与有限的观测数据相结合是一种更灵活的选择。我们于2021年5月17日至6月4日在中国渤海进行了巡航观测实验。基于相干多普勒激光雷达观测的风廓线以及天气研究与预报（WRF）模型输出的温度和压力廓线，我们应用塔塔尔斯基湍流模型来估算渤海晴空大气边界层中的折射率结构常数 2。通过结合垂直速度方差 2、偏度S和峰度K，研究了渤海大气边界层中湍流的时空变化。通过无人机探空仪和激光雷达的实验测量，评估了WRF中模拟的 2和气象参数在渤海大气边界层中的性能。最后，我们给出了渤海大气边界层中 2随高度变化的模型。结果表明，WRF在大多数情况下能够较好地模拟 2。实测和模拟的 2之间的偏差在一个数量级以内，均方根误差（RMSE）在两个数量级以内。由于WRF存在潜在的不确定性，实测和模拟风速之间的RMSE为4 m/s至6 m/s，几乎是先前对陆地表面研究结果的两倍。当湍流充分混合且发展时， 2和 2的总体变化相似，这表明在光学和动力学湍流方面具有一致性。但这种一致性并非绝对。海面与大气之间的温差导致渤海从海面到数百米存在广泛的逆温层。逆温层的抑制削弱了近海面湍流。在整个边界层中，逆温层下方湍流强度增强，从逆温层上方到边界层顶部则减小，而且拐点位置由逆温层顶部高度决定。本研究的主要结果对进一步了解MABL中湍流的发展和变化特征具有参考意义。
