湿度对近地面大气湍流测量不确定性影响研究

Uncertainty research of humidity on the measurement of near-ground atmospheric turbulence

采用多项式法模拟近地面大气湍流,并与实验现场基于温度脉动原理的双点法实测近地面大气湍流进行比对,一方面可以充分利用实验现场的实测温湿压等气象参数进行模拟实验,为研究工作的开展提供便利条件;另一方面可以使研究工作达到科学实际的效果。文中着重研究了在相对湿度较高的环境里实测湍流与多项式法模拟湍流之间的相关性、以及在重新拟合多项式系数后两者之间的相关性变化,从中研究了双点法测量近地面大气湍流的不确定性。分析结果表明:多项式法模拟近地面大气湍流与双点法实测湍流之间在湿度相对较高的环境里相关性较强,且能够维持较高的稳定性,但在相对湿度达到80%以上的环境里两者之间的相关性则明显降低,甚至于出现负值,由此证明双点法测量近地面大气湍流在相对湿度大(80%以上)的环境里存在较大的不确定性。

By virtue of polynomial theory, the near-ground atmospheric turbulence was simulated, which was compared with the near-ground atmospheric turbulence measured by the two-point theory based on temperature fluctuation principle in experimental field. Firstly, the work could take full advantage of the measured meteorological parameters at the experimental site such as temperature, humidity and pressure to carry through the simulation experiment, which provided advantage for the research work. Secondly, practical scientific results could be obtained by the work. In this paper, it focused on the research of correlation between measured turbulence and simulated turbulence by the polynomial theory on condition of relatively high humidity and related changes after refitting polynomial coefficients, and the uncertainty of near-ground atmospheric turbulence measured by the two-point theory was studied. The results show that a strong correlation exists between near-ground atmospheric turbulence simulated by the polynomial theory with near-ground atmospheric turbulence measured by the two-point theory on condition of relatively high humidit. And both can maintain a high stability. But when the relative humidity arrives at 80% or more, the correlation debases significantly, even presents negative value, which proves that thenear-ground atmospheric turbulence measured by the two-point theory has greater uncertainty under the condition of relatively high humidity （80% or more）.