海河流域多尺度地表通量与气象要素观测数据集：怀来站大孔径闪烁仪（2023）

该数据集包含了2023年1月1日至2023年12月31日的大孔径闪烁仪观测数据，分别架设了两台型号为BLS450和zzlas的大孔径闪烁仪。站点位于河北省怀来县东花园镇，下垫面玉米。观测点的经纬度是115.7880E, 40.3491N，海拔480m。大孔径闪烁仪的有效高度为14m，光径长度是1870m，发射端经纬度是115.8023E，40.3596N，接收端的经纬度是115.7825E，40.3522N。BLS450和zzlas的采集频率分别为5Hz和1Hz，平均为1min输出。
大孔径闪烁仪原始数据为1min，发布的数据为经过处理与质量控制后的30min平均数据，其中感热通量主要是结合自动气象站数据，基于莫宁-奥布霍夫相似理论通过迭代计算得到。在迭代计算过程中，对于BLS450，选取Thiermann and Grassl，1992的稳定度函数；对于zzlas，选取Andreas,1988的稳定度函数。主要的质量控制步骤包括：（1）剔除Cn2达到饱和的数据；（2）剔除解调信号强度较弱的数据；（3）剔除降水时刻及其前后一小时的数据；（4）剔除稳定条件下的弱湍流的数据（u*小于0.1m/s）。
关于发布数据的几点说明：（1）LAS数据以BLS450为主，缺失时刻由zzlas观测补充，两者都缺失则以-6999标记。（2）数据表头：Date/Time：日期/时间，Cn2：空气折射指数结构参数（m-2/3），H_LAS：感热通量（W/m2）。数据时间的含义，如0:30代表0:00-0:30的平均；数据以*.xls格式存储。
观测试验或站点信息请参考Guo et al. (2020)，数据处理请参考Liu et al. (2013)。

This dataset contains large aperture scintillometer (LAS) observation data from January 1, 2023 to December 31, 2023. Two LAS instruments with model numbers BLS450 and zzlas were deployed respectively.

The observation site is located in Donghuayuan Town, Huailai County, Hebei Province, with corn as the underlying surface. The coordinates of the observation point are 115.7880°E, 40.3491°N, and the elevation is 480 m. The effective height of the LAS is 14 m, and the optical path length is 1870 m. The coordinates of the transmitter end are 115.8023°E, 40.3596°N, and those of the receiver end are 115.7825°E, 40.3522°N. The sampling frequencies of BLS450 and zzlas are 5 Hz and 1 Hz, respectively, and 1-minute averaged data are output.

The raw LAS data are at 1-minute resolution, while the released data are 30-minute averaged data after processing and quality control. The sensible heat flux is mainly calculated iteratively based on the Monin-Obukhov similarity theory, combined with automatic weather station data. In the iterative calculation process, the stability function proposed by Thiermann and Grassl (1992) is selected for BLS450, while that proposed by Andreas (1988) is selected for zzlas. The main quality control steps are as follows: (1) Remove data with saturated Cn²; (2) Remove data with weak demodulated signal strength; (3) Remove data during precipitation and one hour before and after the precipitation event; (4) Remove data with weak turbulence under stable conditions (friction velocity u* < 0.1 m/s).

Notes on the released data: (1) The LAS data are primarily sourced from BLS450, with missing time periods supplemented by zzlas observations. If both instruments have missing data, the value -6999 is used as the marker. (2) The table headers are: Date/Time, Cn² (air refraction index structure parameter, m^-2/3), H_LAS (sensible heat flux, W/m²). The meaning of the data timestamp: for example, 0:30 represents the average over the period 0:00-0:30. The data are stored in *.xls format.

For details of the observation experiment and site information, please refer to Guo et al. (2020); for data processing procedures, please refer to Liu et al. (2013).