Meteorological observations of quasi-stationary long-lived convective boundary layers

Experimental data for validation of the non-conventional vision on convective turbulence proposed by Zilitinkevich et al., 2020: https://arxiv.org/abs/2005.07680. The data were obtained from meteorological observations at the North-East Siberian station Tiksi in the conditions of long-lived convective boundary layer typical of arctic summer. So, permanent warming of the layer from the surface was balanced by permanent pumping of the colder air into the layer via general-circulation mechanisms. This balance yielded a quasi-stationary regime of turbulence that, in turn, assured accurate estimation of turbulent energies and fluxes, practically unachievable in the conditions of short-lived non-stationary convective layers typical of mid-latitudes. Turbulent energies and fluxes were calculated directly from the measured velocity and temperature fluctuations, whereas the pressure-velocity correlations happened to be negligibly small. Data on the viscous dissipation were retrieved via the Kolmogorov -5/3 power law from the measured spectra of TKE, namely, from their high-frequency intervals corresponding to the direct cascades of mechanical TKE towards its viscous dissipation.

本数据集用于验证Zilitinkevich等人2020年提出的对流湍流非常规研究范式，相关研究原文见：https://arxiv.org/abs/2005.07680。数据源自西伯利亚东北部提克西（Tiksi）气象站的气象观测序列，采集场景为北极夏季典型的长寿命对流边界层环境。在此类环境中，边界层受到的地表持续加热，与通过大气环流机制持续注入的冷空气形成热量平衡，进而催生了准稳态的湍流流态。这一状态为湍流能量与通量的精准估算提供了保障——而在中纬度地区典型的短寿命非稳态对流边界层环境中，此类精准估算几乎无法实现。湍流能量与通量直接通过实测的速度与温度脉动计算得到，其中压力-速度关联项的影响极小，可忽略不计。粘性耗散数据则通过柯尔莫哥洛夫（Kolmogorov）-5/3幂律，从实测的湍流动能（Turbulent Kinetic Energy, TKE）频谱中提取，具体选取对应机械湍流动能直接级联至粘性耗散的高频区间。