关于我国北方沙尘暴的几点思考

沙尘暴是我国北方春季较为常见的一种灾害性天气现象。近几年 ,北方的沙尘暴危害引起各界极大关注 ,国家在应对沙尘暴灾害方面也投入了可观的人力和财力。由于专业背景和部门差异等方面的原因 ,各界在有关沙尘暴演化、成因、源区、传播路径和防治策略等问题上可谓仁者见仁、智者见智 ,至今仍缺乏共同认识。笔者根据近年来研究和思考 ,对上述问题提出几点未必成熟的看法 ,供关心此事的各界同人参考。一、是增多了还是减少了?作为一种灾害性天气 ,大家首先关心的是沙尘暴事件是增多了还是减少了。当前人们一般的感觉是 ,沙尘暴越来越多了 ,危…     

中国沙尘暴及其监测预警

利用1954—2001年中国大陆681个站的气象资料，分析了中国沙尘暴的时空分布特征和分级标准，给出了沙尘暴若干观测事实。通过分析沙尘暴的发生发展机制，讨论了沙尘暴的定性预报和定量预报技术，指出发展包含大气运动、风蚀物理过程和下垫面地表信息的集合数值预报模式是沙尘暴定量预警技术的发展方向。同时，指出传统的监测网尚不能全面监测沙尘暴的发生和发展，建立包含下垫面生态环境要素、大气物理化学要素的专业化沙尘监测网络是深化对沙尘暴特性认识和发展沙尘暴定量预警技术的基础。     

北疆沙尘暴天气气候特征分析

根据新疆地面气象记录月报表,整理出1961-1999年39a北疆40个气象观测站的沙尘暴天气现象资料并进行统计分析,给出北疆地区沙尘暴天气的时空分布特征.结果表明:北疆沙尘暴的高发区在古尔班通古特沙漠,沙漠南缘、天山北麓发生的沙尘暴多于其他周边地区;沙尘暴集中出现在4-8月,多发时段在15-23时,傍晚是活动高峰;沙尘暴持续时间多数在1h以内,最长可持续16h.     

近40年陕西省扬沙和沙尘暴天气

目的 对扬沙和沙尘暴进行分析，以便得出陕西省沙尘天气的时空分布特征；为进一步研究沙尘天气发生的物理机制奠定基础。方法 利用1961-2000年陕西省97个台站的气象实测资料，通过数理统计方法及对比分析，近40年陕西省扬沙和沙尘暴天气的时空分布特征及变化趋势被得出。结果 陕西省扬沙和沙尘暴天气主要发生在3～6月，一般出现在下午和傍晚；扬沙和沙尘暴在陕西省的空间分布特征总体是北多南少，近40年扬沙和沙尘暴出现频数在20世纪80年代后呈下降趋势，20世纪末到本世纪初有一个明显的回升趋势。结论 扬沙和沙尘暴天气的出现频数于20世纪80年代后呈下降趋势，20世纪末到本世纪初有一个明显的回升趋势。     

中国北方农牧交错带形成之探讨

在综述前人对中国北方农牧交错带及其形成原因的研究的基础上,分析了农牧交错带的成因和过程,认为农牧交错带是经过长期演变形成的,是自然因素和人为因素共同作用的结果．自然因素特别是气候干湿波动对其形成和空间上的摆动有着深刻影响,人为因素尤其是农垦活动仅在自然因素基础上起着加速现代农牧交错带分布格局的形成和促使农牧界线频繁摆动的作用．     

我国沙尘暴的时空分布

世界上有四大沙尘暴多发区：中亚的温带沙漠气候区周围、北美加利福尼亚热带沙漠气候区、非洲撒哈拉热带沙漠气候区和澳大利亚中西部的热带沙漠气候区。这些沙漠地区不仅影响其周围地区，而且沙尘也被行星风系带到很远的地方，如撒哈拉沙漠的沙尘被西南风带到瑞士形成泥雨，中亚的沙尘被西风带到我国等。     

我国北方干旱的时空分布特征分析

通过对北方干旱和半干旱地区时间序列的降雨、径流等资料研究,采用降雨距平百分率和分时段多年降雨空间分布分析方法,进一步了解我国北方降雨,径流与干旱空间变化的全貌,并据此对北方各主要地区的干旱情况进行了分析,为全面掌握、研究和预测北方干旱和生态环境的演变发展奠定基础。     

关注生态危机--沙尘暴引发的思考

今年入春以来,我国北方地区不断遭受沙尘暴的袭击,北京已经是第7次遭遇沙尘天气,南方一些城市也受到不同程度的影响.     

沙尘暴的危害成因及减灾对策

近几年来，我国西北、华北的沙尘暴发生频率越来越高，持续时间越来越长，且沙尘暴出现得越来越早，越来越猛烈，严重地影响了广大人民群众正常的工作和生活，沙尘暴已成为最具危害的自然灾害之一。据资料统计，沙尘暴有不断扩大和蔓延的趋势，最明显的影响是造成直接的经济损失，土地沙漠化不断加重、扩大，生态环境恶化。因此，防治沙漠化,减少沙尘暴，则成为这一区域可持续发展的重要保障。     

大同市沙尘暴时空分布特征及其主要影响系统分析

通过对大同地区1970-2002年8个气象观测站的沙尘暴资料进行研究分析,得出其时空分布特征和主要影响系统。结果表明：大同地区沙尘暴西部多东部少,春季是高发期;20世纪70-80年代多,出现沙尘暴天气的主要影响系统是冷锋和气旋。     

塔中石油基地沙尘天气的变化趋势及影响因素

通过对塔中石油基地1997-2005年浮尘、扬沙和沙尘暴的季节变化和年际变化分析,表明;塔中沙尘天气多出现在春、夏两个季节。塔中沙尘天气近9a总的趋势是整体平稳,变化幅度不大,沙尘暴的日数减少,浮尘和扬沙日数有所增加。沙尘天气与气温、降水、蒸发量、季风等气象要索有一定的关系,同时也受到人类活动的影响。     

Great progress in study on aerosol and its impact on the global environment

The transport from atmosphere is a more important pathway than that from rivers for certain elements and compounds in the remote ocean. The desert and those arid/semi-arid areas in the northwest of China and the Loess Plateau are the sources of those aerosols over the Pacific. Atmospheric iron is the limiting factor of the productivity in certain ocean regions. The dust storms must now be seen as repeated sources of pollution elements as well as soil elements to the East China Sea and, farther out, to the North Pacific Ocean and even to the USA. The long-range transport of aerosols, especially the dust storm, from China and the positive feedbacks of iron coupled with sulfur in atmosphere might be one of the important mechanisms that would affect the primary productivity in the Pacific and/or the global climate change and deserve to be further studied. It can be seen clearly that the dust storms would affect not only the health of human beings and the local or regional climate, but also the global climate change that has been the focus of environmental study internationally.     

我国北方沙尘暴灾害及防治对策

沙尘暴是与风沙活动、土地沙漠化过程密切相关的一种发生在沙漠及其邻近地区的灾害性天气现象 ,它是高速运行气流即大风与干燥裸露地表相互作用所形成的 ,是干旱与沙漠化气候环境的产物。我国的沙尘暴主要发生在西北、华北和东北西部 ,尤以西北地区的沙尘暴发生频繁、危害严重、影响范围广泛。它的发生、发展除与大气环流、下垫面状况等自然因素有关外 ,人类大量开垦农田、放牧、樵采、过渡利用地表和地下水资源以及进行各种工矿、交通建设等活动 ,破坏了地表植被和土壤层 ,使表土裸露直接遭受风力侵蚀作用 ,既加速了沙漠化土地的扩展 ,也扩大了沙尘源 ,使沙尘暴发生的频率和强度大为增加。为此 ,本文分析了我国沙尘暴的空间分布范围、运移路径、形成原因和危害表现 ,并提出了防治沙尘暴的对策建议     

黄羊滩沙地的形成及其对北京沙尘暴天气的影响

对黄羊滩沙地进行物质成分分析、粒度分析和扫描电镜观察,结果表明:黄羊滩沙地的物质具有二源性特征,分别来源于黄羊滩洪积台地洪积物和洋河冲积物.根据沙地发育条件和历史过程,认为黄羊滩沙地不会有大的扩展.以粒度数据为基础,估算出黄羊滩沙地沙丘φ值大于4的沙尘年平均输出量为7.98×102 t*a-1,φ值大于7的沙尘年平均输出量为3.23×102 t*a-1,占年沙尘输出量的40.5%.北京沙尘暴沙尘组分以φ值大于6.8的为主,黄羊滩沙地对北京沙尘暴天气的沙尘有一定的贡献量.     

中国北方地区环境演变对新石器文化发展的影响

通过对中国北方地区新石器文化遗址的14C数据和遗址分布特点与环境演变研究成果的对比研究得出:在暖湿气候条件下,中原文化北上,东部文化西进,新石器文化稳定发展;气候转为干冷时,新石器文化向东向南迁移.气候恶化导致北方地区"文化事件"频发,许多新石器文化发生更替现象.全新世气候环境演变,叠加在中国北方地区资源、环境的地带性特点以及新石器文化分布的背景之上,是中国北方地区新石器文化发展与文明形成的主要动力与机制.     

Dust storms and loess accumulation on the Tibetan Plateau：A case study of dust event on 4 March 2003 in Lhasa

Whether the Tibetan Plateau is a significant dust source area is of great importance, because this is related to the understanding of sources, accumulation and environmental effects of dusts on the Tibetan Plateau and inthe Far East-Pacific Ocean regions as well as to the evointion of coupling of the Tibetan Plateau and atmaspbere-oeean-continent exchange. Synoptic dynamics and remote sensing tracing of a dust storm on 3 to 5 March, 2003 in Lhasa onSouth Tibet demonstrate that the Tibetan Plateau possessesall factors and conditions of generating dust storms. Accompanied with this dust storm is a strong ascending stream onthe Plateau which has raised various sizes of durst particlesinto different levels. The lifted coarse particles were largelyfallen down and accumulated as loess on the eastern TibetanPlateau, and the fine particles were translated by the westerly jet and subsided in the northern Pacific Ocean. The spa-tial-temporal distribution of dust-storms between years 1961and 2000 ou the Plateau shows that duststorms mainly occurin winter and early spring with high frequency, and tile pathof dust storm moves gradually from south to north, which isclosely coupled with the northward moving of the westerlyjet from winter to spring over the Tibetan Plateau. Com-pared with other twelve dust source areas in China. the Ti-betan Plateau is one of the key dust souree areas for thelong-distance transport because its high occurring frequencyand elevation cause fine particles easily to be lifted into thezone of the westerly jet.     

风沙流/沙尘暴与高雷诺数壁湍流野外观测

 风沙流与沙尘暴是发生在高雷诺数大气边界层中的气固两相流,对风沙流与沙尘暴的深入认识、准确预报和科学防治都要基于对风沙运动规律的认知和把握,因而需要借鉴高雷诺数湍流的研究成果。本文综述了高雷诺数壁湍流和风沙流/沙尘暴研究的现状,着重介绍了在中国民勤地区建立的沙尘暴与高雷诺数壁湍流野外观测站,以及基于观测站的观测列阵所获得的初步成果,展望了进一步的发展方向。     

The trend of sand flux and the meteorology elements changes in the near-surface layer of Tengger desert in the spring of 2006

Dust storm events, especially those associated with strong winds, are immediately dangerous, and have long-term harmful effects. During a dust storm event, dust in the near-surface atmospheric layer decreases visibility, and changes local meteorological parameters. In this paper, we analyzed levels of near-surface turbulence during and outside a dust storm event and found differences in the degree of turbulence, with wind speed increasing and amounts of windblown sand greatly increasing air turbulence during the dust storms compared with the corresponding values on a sunny day. In addition, the wind profile during the dust storm deviated from the normal profile and became more complex. In the near-surface atmospheric layer, sand and dust flux during the dust storm also differed from those on a sunny day.     

2008年8月10日华北雷暴暴雨天气过程分析

采用地面观测、探空资料和卫星云图等,对2008年8月9日至11日在河北、京、津地区的一次大范围暴雨天气过程系统的发生发展、结构与成因进行了综合分析。     

The compositions, sources, and size distribution of the dust storm from China in spring of 2000 and its impact on the global environment

The average mass concentration of the aerosols in Beijing during the dust storm in the spring of 2000 was ~6000 mg·m^-3, ~30 times as high as that in the non-dust storm days. The enrichment factors of the pollution elements As, Sb and Se were higher than those in the non-dust storm days. This indicated that As, Sb and Se resulted from the pollution sources of those areas, through which the dust storm passed during their long-range transport, in addition to the local pollution sources in Beijing. The enrichment factors of the Pb, Zn, Cd and Cu were much less than those in the non-dust storm days, suggesting that the local pollution sources in Beijing area contributed to them mostly. The enrichment factors of elements Al, Fe, Sc, Mn, Na, Ni, Cr, V and Co were close to 1, showing that these elements originated from crust. The concentration of S in the dust storm was ~10 mg·m^-3, 4 times as high as that in non-dust storm. S in the aerosols resulted from the adsorption of gaseous SO₂ and the consequent transformation on it. The aerosols of the dust storm contained 16.1% and 76.9% of fine particles with the sizes less than 2.1 and 9.0 mm, respectively, while it had a large number of coarse particles. It was noted that a considerable portion of Fe(Ⅱ) was detected from the dust storm. Fe(Ⅱ) could easily dissolve in seawater to be nutrient for phytoplankton and would lead to the increase of the emission of dimethylsulfide (DMS) from the ocean. The feedbacks of Fe coupled with S in atmosphere might be the important mechanism that would affect the primary productivity in Pacific and/or the global climate change.