分别在南京的两个钢铁厂收集降尘并采集周边表土,并用ICP-AES和磁化率仪分析得到16种元素含量和表土、地面尘的磁化率。结果表明,两个钢铁工业区的大气降尘的年沉降通量分别为190t km-2a-1和407 t km-2a-1,这可能会影响着周边地区土壤...分别在南京的两个钢铁厂收集降尘并采集周边表土,并用ICP-AES和磁化率仪分析得到16种元素含量和表土、地面尘的磁化率。结果表明,两个钢铁工业区的大气降尘的年沉降通量分别为190t km-2a-1和407 t km-2a-1,这可能会影响着周边地区土壤的形成;Al、K、Na、Ti、V在降尘中的含量显著低于表土,而Ca,Fe,Zn,Mn,Pb,Cu在降尘中含量要显著高于表土;表土的磁化率除水田外均大于100×10-8m3kg-1,并且地面尘的磁化率要远远高于表土的磁化率。研究表明,钢铁工业区降尘对其周边土壤中污染元素的积累有明显影响,突出地表现在土壤表层重金属含量升高,而磁化率可以很好地表征这种表聚的特点。展开更多
The Taklimakan Desert(TD) and Gobi Desert(GD) are two of the most important dust sources in East Asia, and have important impact on energy budgets, ecosystems and water cycles at regional and even global scales. To in...The Taklimakan Desert(TD) and Gobi Desert(GD) are two of the most important dust sources in East Asia, and have important impact on energy budgets, ecosystems and water cycles at regional and even global scales. To investigate the contribution of the TD and the GD to dust concentrations in East Asia as a whole, dust emissions, transport, and deposition over the TD and the GD in different seasons from 2007 to 2011 were systematically compared, based on the Weather Research and Forecasting model coupled with Chemistry(WRF-Chem). Dust emissions, uplift, and long-range transport related to these two dust source regions were markedly different due to differences in topography, elevation, thermal conditions, and atmospheric circulation. Specifically,the topography of the GD is relatively flat, and at a high elevation, and the area is under the influence of two jet streams at high altitudes, resulting in high wind speeds in the upper atmosphere. Deep convective mixing enables the descending branch of jet streams to continuously transport momentum downward to the mid-troposphere, leading to enhanced wind speeds in the lower troposphere over the GD which favors the vertical uplift of the GD dust particles. Therefore, the GD dust was very likely to be transported under the effect of strong westerly jets, and thus played the most important role in contributing to dust concentrations in East Asia. Approximately 35% and 31% of dust emitted from the GD transported to remote areas in East Asia in spring and summer, respectively. The TD has the highest dust emission capabilities in East Asia, with emissions of about 70.54 Tg yr.1 in spring, accounting for 42% of the total dust emissions in East Asia. However, the TD is located in the Tarim Basin and surrounded by mountains on three sides. Furthermore, the dominant surface wind direction is eastward and the average wind speed at high altitudes is relatively small over the TD. As a result, the TD dust particles are not easily transported outside the Tarim Basin, such that most of 展开更多
文摘分别在南京的两个钢铁厂收集降尘并采集周边表土,并用ICP-AES和磁化率仪分析得到16种元素含量和表土、地面尘的磁化率。结果表明,两个钢铁工业区的大气降尘的年沉降通量分别为190t km-2a-1和407 t km-2a-1,这可能会影响着周边地区土壤的形成;Al、K、Na、Ti、V在降尘中的含量显著低于表土,而Ca,Fe,Zn,Mn,Pb,Cu在降尘中含量要显著高于表土;表土的磁化率除水田外均大于100×10-8m3kg-1,并且地面尘的磁化率要远远高于表土的磁化率。研究表明,钢铁工业区降尘对其周边土壤中污染元素的积累有明显影响,突出地表现在土壤表层重金属含量升高,而磁化率可以很好地表征这种表聚的特点。
基金supported by the National Natural Science Foundation of China (Grant No. 41405003)Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 41521004)+1 种基金the Programme of Introducing Talents of Discipline to Universities (Grant No. B 13045)the Foundation of Key Laboratory for Semi-Arid Climate Change of the Ministry of Education in Lanzhou University
文摘The Taklimakan Desert(TD) and Gobi Desert(GD) are two of the most important dust sources in East Asia, and have important impact on energy budgets, ecosystems and water cycles at regional and even global scales. To investigate the contribution of the TD and the GD to dust concentrations in East Asia as a whole, dust emissions, transport, and deposition over the TD and the GD in different seasons from 2007 to 2011 were systematically compared, based on the Weather Research and Forecasting model coupled with Chemistry(WRF-Chem). Dust emissions, uplift, and long-range transport related to these two dust source regions were markedly different due to differences in topography, elevation, thermal conditions, and atmospheric circulation. Specifically,the topography of the GD is relatively flat, and at a high elevation, and the area is under the influence of two jet streams at high altitudes, resulting in high wind speeds in the upper atmosphere. Deep convective mixing enables the descending branch of jet streams to continuously transport momentum downward to the mid-troposphere, leading to enhanced wind speeds in the lower troposphere over the GD which favors the vertical uplift of the GD dust particles. Therefore, the GD dust was very likely to be transported under the effect of strong westerly jets, and thus played the most important role in contributing to dust concentrations in East Asia. Approximately 35% and 31% of dust emitted from the GD transported to remote areas in East Asia in spring and summer, respectively. The TD has the highest dust emission capabilities in East Asia, with emissions of about 70.54 Tg yr.1 in spring, accounting for 42% of the total dust emissions in East Asia. However, the TD is located in the Tarim Basin and surrounded by mountains on three sides. Furthermore, the dominant surface wind direction is eastward and the average wind speed at high altitudes is relatively small over the TD. As a result, the TD dust particles are not easily transported outside the Tarim Basin, such that most of
