Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： This study utilized observational data on floating dust days from multiple stations across the TarimBasin spanning 2011 to 2020. In total, 396 days characterized by persistent floating dust were selected.Employing ERA5 meteorological reanalysis data, the PCT algorithm was used to objectively classify near-surfaceand upper- layer circulation patterns associated with persistent floating dust in the Tarim Basin. Furthermore,typical synoptic processes accompanying persistent floating dust were selected for analysis. The aim was toelucidate the relationship between persistent floating dust and synoptic circulation at different altitudes. Thefindings revealed three distinct near-surface weather patterns during persistent floating dust days: high-pressurefront, high- pressure bottom, and uniform pressure field. Variations in meteorological conditions and pollutantconcentrations were evident among these surface weather patterns. The near- surface weather system evolvedfrom the high-pressure front to high-pressure bottom, culminating in the uniform pressure field. The upper-layerweather system alternated between the westerly trough type and the high-pressure ridge-zonal latitudinal type. Asthe Siberian cold high-pressure system moved eastward and southward, upper-layer circulations were influencedby the westerly trough and the Iranian high- pressure system. Persistent floating dust events occurred anddeveloped alongside elevated near- surface PM10 concentrations. These events concluded when a near- surfaceuniform pressure field prevailed, marked by limited air pressure system activity and an upper- layer circulationcharacterized by the zonal latitudinal pattern.
Subjects: Geosciences >> Geography submitted time 2022-09-26 Cooperative journals: 《干旱区研究》
Abstract：风沙运动是区域与全球变化研究中不可忽视的地表过程。起沙阈值（临界起沙风速、临界起沙摩擦速度） 作为判定风沙运动是否发生的关键参数，是风沙运动研究的核心问题。利用塔克拉玛干沙漠腹地野外同步观测的 风沙运动和气象资料，结合数理模型计算，定量评估了Stout、Kurosaki and Mikami（KM）、李晓岚和张宏升（LZ）、Mar⁃ ticorena and Bergametti（MB）、Shao and Lu（SL） 5种起沙阈值判定方案的适用性，并利用最优方案确定了研究区新的 起沙阈值。结果表明：（ 1）5种方案均存在不确定性，KM方案确定的起沙阈值一定程度上高估了起沙时长与沙尘 水平通量，其他4种方案则相反，但KM方案最优。（ 2）塔克拉玛干沙漠腹地2 m高度临界起沙风速变化范围为4.0~ 6.0 ms-1，临界起沙摩擦速度变化范围为0.24~0.36 ms-1；起沙阈值具有季节性差异，符合夏季>秋季>春季>冬季的 变化规律。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：利用塔克拉玛干沙漠腹地-塔中地区的风速、风向观测资料，分析晴天、沙尘暴和扬沙天气条件下不同高度平均风速、风速脉动和风向脉动特征，探讨沙尘天气对近地层风速和风向脉动的影响。结果表明：① 3种天气条件下，地表0.5 m以上各高度层的脉动风速具有较好的相关性，且相邻高度脉动风速的相关性更加显著，相关系数均大于0.68；脉动风速的波动范围与高度呈正比例关系。② 随着高度的增加，沙尘暴和扬沙天气条件下的风速脉动强度呈增大趋势，而晴天时则是先增大后减小；风速脉动强度在沙尘暴天气时最大，扬沙天气次之，晴天最小；不同天气条件下2 m高度范围内风速脉动强度的增长速度大于2~10 m高度。③ 不同天气条件下风向脉动幅度均较小，且基本不随高度的改变而变化。
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