OBSERVATIONS OF TEMPERATURE MICROSTRUCTURE IN THE ATMOSPHERE

In order to provide data of atmospheric temperature microstructure for the investigation of light propagation we measured fluctuations of atmospheric temperature below the height of 300 m with a platinum wire thermometer in Tianjin in May and September, 1980. The results measured in daytime revealed some properties of the temperature structure parameter and spectrum. It has been confirmed that there is a maximum in the profile of the structure parameter produced probably by the entrainment in the interfacial layer at the top of convective boundary layer. The average of CT2 in the interfacial layer and its Wyngaard calculating method are discussed, and the thickness of the interfacial layer is obtained.It is shown by spectrum analysis that a wide inertial subrange exists in the convective boundary layer and the strong turbulent zone in the free atmosphere. The spectral law with the power of -2.5 was measured within the upper half of boundary layer over the sea in vicinity of Tanggu.     

温度微结构的高空气球观测

本文给出了在河北省香河县的一次高空气球垂直探测大气温度起伏的主要结果。由气球吊篮上端同一水平线上三个钨丝温度计测量的温度起伏计算出不同水平和垂直距离的湍流结构常数。结果表明:大气在大于0.33～1.07 m的范围满足Kolmogorov的2/3定律,垂直方向温度谱分析表明-5/3幂率区可达20 m以上。文章还讨论了小尺度湍流的各向同性问题。     

近海面气层温度结构常数的模式和测量

文中采用一个边界层湍流模式估算海面上温度结构常数C2T,模式输入的参数是气温、海表面温度和风速。模式估算的C2T与1999年6月在东海实测的C2T相当一致,此外,还对估算方法详细进行了敏感性分析。认为在估算C2T时,对温度测量的精度要高,选用Thiermann公式比较好。     

大气温度微结构观测

1980年5月和9月在天津地区用铂丝电阻温度计测量了3000米高度以下大气的温度起伏。白天的测量结果说明了温度结构常数和谱的一些特征。 证实了结构常数廓线在对流边界层顶的介面层有一个可能由夹卷作用产生的极大值。文章还讨论了界面层C_T~2的平均值及其Wanaaard的计算方法,给出了界面层的厚度。 谱分析表明,对流边界层、自由大气中的强湍流带有较宽的惯性区。在自由大气中谱分析将受湍流间歇性的影响。在塘沽附近海面上边界层的上半部曾得到幂率为—2.5的谱。     

An Analysis of the Turbulent Structure in the Unstable Surface Layer nearby a Shelter Belt

An analysis was performed of the turbulent data obtained from Yucheng experimental station in the Shandong Province in 1984. [t is shown that at variant wind speed, the spectra of streamwise velocity remain similar and the intensity of wind fluctuations is proportional to wind speed in the downwind area of shelter belt. Therefore, we may decide the similarity of wind fluctuations by a speed scale and a length scale which is not correlated with stability, σu /V0 = F(X / H). The -5/3 power range of temperature spectra extends to lower frequency. The variation of ratio σ0 /T. with stability becomes σ0 / T . = C(X / H)( - Z / L)-1/3 . There is not such an extension of -5 / 3 power range in the humidity spectra.     

湍流的不连续性和柯尔莫果洛夫的湍流理论

湍流的不连续性和现在流行的柯尔莫果洛夫理论有矛盾。本文描述了1972年9月我们在东北地区做实验时观测到的不连续现象,计算了它们的统计特征,特别是初次得到了不连续尺度的统计特征,分析了它们和柯氏湍流模型矛盾之点,从而指出建立更正确更完整的理论的必要。     

大气边界层的室内模拟研究--夹卷层温度场结构分析

利用室内水槽模拟大气对流边界层,并用多探头测量和光学方法测量分析夹卷层的夹卷过程和温度场结构.测量结果表明,夹卷层的温度场不同于各向同性湍流场,主要原因是夹卷层中含有一些大尺度的相干涡旋.