沙尘天气过程临界起沙因子的研究进展

Review of the Threshold for Dust Emission during Dust Events

临界起沙摩阻风速u*t或临界起沙风速ut是土壤可蚀性的度量指标之一,是表征沙尘颗粒进入大气的重要因子,也是沙尘暴预报模块中最重要的参数之一。野外实验、模式参数化和统计理论是近年来确定临界起沙摩阻风速u*t或临界起沙风速ut的3种主要方法。利用不同方法获取u*t或ut的结果可以相互校验。野外实验的实测结果可为获取适用的起沙判据、改进起沙阈值的参数化方案提供基础。在回顾利用不同方法获取临界起沙摩阻风速的结果、应用,及其代表性、一致性和差异的基础上,有针对性地提出存在的问题和今后发展的建议。

Threshold friction velocity u＊t or threshold velocity ut represents the erodibility of soil and is the critical factor for dust emission into the atmosphere. It is also one of the most important parameters in dust emission schemes, and can be determined via three widely used methods, namely, observation through field experiments, model parameterization and statistical calculation. The results obtained by different methods can be compared and validated. The dust emission criterion could be established and the parameterization schemes for dust emission threshold could be improved based on the results of field experiments. This paper has reviewed the results, applications, representation and differences of various methods. The remaining problems and suggestions in the future have been pointed out.