Meteorological aspects associated with dust storms in the Sistan region, southeastern Iran
Meteorological aspects associated with dust storms in the Sistan region, southeastern Iran
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DOI：
10.1007/s00382-014-2208-3
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发表时间：
2015-07
期刊：
影响因子：
4.6
通讯作者：
D. Kaskaoutis;A. Rashki;E. Houssos;Abbas Mofidi;Daisuke Goto;A. Bartzokas;P. François;Michel Legrand
中科院分区：
文献类型：
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作者：
D. Kaskaoutis;A. Rashki;E. Houssos;Abbas Mofidi;Daisuke Goto;A. Bartzokas;P. François;Michel Legrand
沙尘暴被认为是严重影响大气条件、生态系统和人类健康的自然灾害。调查尘埃生命周期的一项关键要求是分析控制尘埃排放、抬升和输送的气象(天气和动力)过程。本工作的重点是审查2001-2012年夏季(6月至9月)伊朗东南部锡斯坦地区与沙尘暴有关的天气和动态气象条件。沙尘暴日数(共356天)与沙尘源附近Zabol气象站1公里以下的能见度记录有关。RegCM4模式模拟结果表明，北半球强风、地面高加热和谷状特征对天气动力学和与沙尘暴露量密切相关的低空急流的形成有强烈影响。尽管大多数沙尘暴与海洋尼诺指数的正值有关，但沙尘暴的年内演变似乎与厄尔尼诺南方涛动没有明显的联系。国家环境预测中心/国家大气研究中心的再分析表明，沙尘暴与整个南亚的低海平面气压条件有关，而在700百帕的水平上，印度上空的低重力高度槽以及阿拉伯和伊朗中部的脊线是常见的情况。一个重要的发现是，锡斯坦上空的沙尘暴被发现与里海上空反气旋的显著增加有关，从而增强了自西向东的气压梯度，从而导致了Levar的吹动。红外差异沙尘指数值突出了锡斯坦沙尘暴的强度，而SPRINTARS模式很好地模拟了沙尘负荷和浓度，因为沙尘暴通常与模式模拟中的峰值有关。
Dust storms are considered natural hazards that seriously affect atmospheric conditions, ecosystems and human health. A key requirement for investigating the dust life cycle is the analysis of the meteorological (synoptic and dynamic) processes that control dust emission, uplift and transport. The present work focuses on examining the synoptic and dynamic meteorological conditions associated with dust-storms in the Sistan region, southeastern Iran during the summer season (June–September) of the years 2001–2012. The dust-storm days (total number of 356) are related to visibility records below 1 km at Zabol meteorological station, located near to the dust source. RegCM4 model simulations indicate that the intense northern Levar wind, the high surface heating and the valley-like characteristics of the region strongly affect the meteorological dynamics and the formation of a low-level jet that are strongly linked with dust exposures. The intra-annual evolution of the dust storms does not seem to be significantly associated with El-Nino Southern Oscillation, despite the fact that most of the dust-storms are related to positive values of Oceanic Nino Index. National Center for Environmental Prediction/National Center for Atmospheric Research reanalysis suggests that the dust storms are associated with low sea-level pressure conditions over the whole south Asia, while at 700 hPa level a trough of low geopotential heights over India along with a ridge over Arabia and central Iran is the common scenario. A significant finding is that the dust storms over Sistan are found to be associated with a pronounced increase of the anticyclone over the Caspian Sea, enhancing the west-to-east pressure gradient and, therefore, the blowing of Levar. Infrared Difference Dust Index values highlight the intensity of the Sistan dust storms, while the SPRINTARS model simulates the dust loading and concentration reasonably well, since the dust storms are usually associated with peaks in model simulations.