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 >> Geology submitted time 2023-08-23 Cooperative journals: 《中国科学院院刊》
Abstract： In order to implement the spirit of General Secretary Xi Jinping’s important speech on strengthening the comprehensive control of desertification and promoting key ecological engineering projects such as the “Three-North Shelterbelt Program”, this study is designated to make concrete efforts to win the battle against desertification on the edge of Hexi Corridor–Taklimakan Desert. The study deeply explores the situation of wind-blown sand flux and prevention tasks in the area. Based on the characteristics of desertified land and wind-blown sand activities on the edge of Hexi Corridor–Taklimakan Desert, the goal is set to effectively prevent the spread of sand and control dust sources. The core focus is on wind prevention, sand resistance, and dust control. The strategic thinking has been formulated for the counterattack battle on the edge of Hexi Corridor–Taklimakan Desert. By systematically analyzing the source areas and paths of “wind, sand, and dust” and targeting the key zones of the desert edge and areas requiring prevention, the key areas and tasks are proposed for desertification control on the edge of the Hexi Corridor–Taklimakan Desert, so as to provide scientific and technological support for winning the battle against desertification on the edge of Hexi Corridor–Taklimakan Desert.
Subjects: Geosciences >> Geography submitted time 2020-01-06 Cooperative journals: 《干旱区地理》
Abstract：利用塔克拉玛干沙漠22个气象站（周边21个站和沙漠腹地1个塔中站）2005—2007年的逐时风记录数据，首先基于输沙势定义计算了2007年各测站的16个方位的输沙势；其次以内积相似度指数聚类分析为基础，再结合其空间分布特点，把该沙漠的动力输沙环境划分为5种类型：沙漠东部库尔勒型（西西南型）、北部新和型（偏南型）、西部策勒型（偏东型）、南部民丰型（东东北型）和一种特殊类型；其中策勒型输沙势最大、新和型最小；民丰型输沙势方向稳定性最好、库尔勒型最差；此外，输沙势的季节差异上（2007年为例），各测站春夏季（3~8月）的输沙势都很强，占年均输沙势的81.29%~98.79%，尤其是5月份占年输沙势的22.7%~56.8%，冬季（11月~次年2月）几乎无起沙风；沙漠合成输沙势年际变化表现为：输沙势变幅为±33%，输沙方向变幅为±9.6°，其中输沙势值变幅最大是阿拉尔站（±80%），方向变幅最大的是库车站（±24.4°）。
Subjects: Geosciences >> Geography submitted time 2019-11-15 Cooperative journals: 《干旱区地理》
Abstract：利用乌鲁木齐市5座100 m气象塔10层气温观测资料，通过统计方法详细分析了乌鲁木齐市城区和郊区近地层不同高度气温季节变化和日变化特征。研究表明：乌鲁木齐市四季均存在逆温，北郊逆温最明显。近地层100 m内主城区气温日较差较小，约为3.5～5.5 ℃；郊区气温日较差较大，约为4.2～7.0 ℃。夏季郊区气温高于城区，冬季北郊气温最低、南郊最高；白天大气基本上为超绝热不稳定状态，夜间城区气温高于郊区。春、秋季，白天城区和郊区温差小、夜间大，且愈近地面温差愈大；春季城区与南郊温差可达2.4 ℃、秋季可达3 ℃。城区和郊区各季节各层最高气温与最低气温出现时间几乎不同步达到。夏季、秋季、冬季和春季最高气温分别约在17:00～18:10、16:00～17:20、14:30～15:50（北郊滞后1.5 h）、17:00～18:00（南郊提前1.5 h）出现，最低气温分别约在7:10～8:20、8:00～9:00、冬季为多个时段（这与出现逆温有关）、7:30～8:40出现。
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。
Hits
Hits
Downloads
Comment