《尘暴》及其对环境史研究的贡献

环境史学在西方兴起于 2 0世纪晚期 ,在中国也许起步更早些 ,但其受到国内史学从业者兴趣日增的关注 ,则是近年来的事 :一方面是缘于西方环境史学发展的促动 ,一方面是因人与自然之间的关系日趋紧张等现实因素的推动。但环境史究竟是历史学的一门分支学科 ,还是一种新的考察人类社会发展历程的视角或方法 ,或者一种新的史学范式和新的通史观念 ,国内外环境史研究者均未形成共识。这组“笔谈”的发表 ,无疑将有助于人们深化对这一新的历史研究领域的认识。“笔谈”的作者包括老中青三代史学从业者 ,虽来自不同的史学领域 ,但都较早涉足环境史研究 :或早在 1973年就开始涉足沙漠研究 ,并多次深入我国北方沙漠地区进行实地考察 ,提出了著名的“沙漠化二重性”论断 ;或长期致力于美国环境史著作的译介 ;或率先在国内高校历史系开设《环境史研究导论》课程 ,培养环境史研究新人 ;或较早运用自然与社会互动关系理论 ,系统地对自然灾害与民国乡村社会变迁问题进行全方位的研究 ,从而拓宽了乡村社会史畛域。因此 ,这组“笔谈”在一定程度上反映了目前国内环境史研究者对于环境史的思想认识及其所达到的水平。“笔谈”的组织 ,得到了北京师范大学历史系梅雪芹副教授的热情支持和全力协助 ,本刊谨此致谢。

读唐纳德·沃斯特的《尘暴》

“2001年3月10日，一场沙尘暴袭击了北京：天空昏暗，交通阻塞，机场关闭。……更让人惊奇的是，这场从新疆、宁夏、甘肃、内蒙古和北京一路吹过来的沙尘暴竟然漂洋过海最终到达了美国东海岸，进入了大西洋。”这就是美国当代著名学者和历史学家唐纳德·沃斯特所著的《尘暴》中文版序中一开始所描述的情景。《尘暴》一书从生态和文化批判这一独特的视角向人们讲述了1930年发生在美国大平原上的生态灾难，并且分析了形成灾难的原因。

历史学与环境问题研究

在环境问题的研究中,历史学有着怎样的价值?这是关系到历史学研究环境问题之合法性的问题。回答这个问题的关键,在于环境问题本身的特点与历史研究的一致性上。环境问题关乎自然,但实质上却是一个社会历史问题,它具有累积突发、性质复杂、责任具体、影响持久、治理艰难等特点,这些都可纳入历史学的研究视野。在以往的环境问题研究中,历史学已经显露出自己的特色,那就是关注多重社会因素间的联系,挖掘深层次的文化根源,细腻而生动地描述事件原委,旗帜鲜明地宣扬价值取向,为现实的环境治理提供借鉴。历史学在政府环境决策和大众环境教育中具有重要意义。

环境史学的历史批判思想

环境史学是对 2 0世纪西方史学的继承与发展 ,其研究内容主要是考察人类及其创造的各种社会与之存在于其中的环境、生态系统之间的关系演变及其后果。明确的批判态度是其显著征候 ,尤其对西方文化的主流价值观念的批判最为集中和猛烈。目前的环境史学正突破始初的道德诉求和伦理色彩 ,深入到文明发展和环境变迁的动态过程之中 ,全面探讨人与自然和人与人之间错综复杂的关系 ,在人类拯救地球家园并自救的探索中起着重要作用。因而 ,综合了新社会学与生态学取向并立足于具体研究的环境史学批判 ,既有学术价值又有现实意义。

Informational digital diagrams applied to predict spring wind,snow,and sandstorms

Using informational digital diagrams, we analyzed the snow event that occurred on Feb 26, 2006 and the sandstorm on Apr 11, 2006 in Xi＇an. Results indicate that, under similar weather circumstances, different events evidently exhibit unique vertical structure features. Informational digital diagrams provide a method for transitional weather prediction, a problem for present extrapolative analysis system.

Features of Sand-dust Deposits in Harbin City,China

From the sedimentologic view, this paper analyses the grain-size distribution and the chemical composition of the deposits from sand-dust storm, occurring in Harbin on March 20, 2002. The result indicates that there exist plentiful coarse matters in the sand-dust deposits in Harbin, and the sand-dust composition presents obvious three peak distribution characteristics, indicating that the sand-dust in Harbin is composed of multi-origin components. The grain-size composition consists of silt （4-8Φ）, accounting for 71.18% of the total, sand （〉4Φ）, 21.70%, and clay （〈8Φ）, only 7.13%. The average grain size （Mz） is 5.14Φ. The chemical elements of the deposits are mainly SiO2 and A1203 and Fe203, totally occupying 77.8%. The enrichment factors （EF） of Mg, K, Si, Fe, Mn, P, Ti, Co, Ni and V elements are all about 1, which mainly come fi＇om lithosphere source, while parts of Cu, Pb, Zn, Cr and Se elements are from pollution sources out of lithosphere source, and As, Cd and Sb elements are mainly from pollution sources. Based on the comprehensive analysis of grain-size, chemical composition, enrichment factor （EF）, discriminant function （DF） and matter source index （PI）, this paper points out that the grain-size distribution and element composition of the sand-dust deposits in Harbin are evidently different from the loess and sand-dust in Lanzhou, and that matter source of the sand-dust in Harbin is different from the loess in Northwest China and the sand-dust in Lanzhon. The sand-dust deposits in Harbin are an admixture of coarse grains transmitted in short distance and fine grains transported in long distance. The plentiful coarse grains of the sand-dust deposits in Harbin origin from sand of local spot, and are the near-souroe deposits transported by low altitude airflow.

Seasonal to interannual prediction of air pollution in China:Review and insight

Complex air pollution problems have resulted in considerable adverse impacts on the environment,human health,and economy in China.However,owing to strict regulations since 2013,the air quality has been greatly improved.Now,the prevention of air pollution has entered a critical stage in combination with climate change mitigation in China.Accurate seasonal to interannual prediction of air pollution(haze,surface 03,and sandstorms) could support the government in planning for air pollution control on an annual basis.Scientists from all over the world have made great progress in understanding climate change and the variability of air pollution and associated physical mechanisms in China,which has provided a scientific basis for the development of climate prediction of air pollution.This paper reviews the progress made in air-pollution climate prediction,and gives some critical insights including update of predictand,change of predictability,and development of coupled model.

PRELIMINARY STUDY ON SAND - DUST STORM DISASTER AND COUNTERMEASURES IN CHINA

As a kind of natural disasters, sand dust storms frequently occur in deserts and their surrounding areas. The occurrence of this disaster in China′s northwest and north China has exerted an extremely adverse effect upon the environment in China. The management of sand dust storms is of a systematic project closely related with the environment such as agriculture, ecosystem, forestry, water conservancy, meteorology and other aspects. Therefore, studies of the formation, the basic features, causes, temporal spatial distribution, developing trend and related disasters of sand dust storms in China are conducted based on satellite data. The experience of sand dust storms control and countermeasures in the United States and some other countries are referred. Meanwhile, preliminary countermeasures relating to sand dust storms in China are proposed.

Correlation of Dust Storms in China with Chlorophyll a Concentration in the Yellow Sea between 1997-2007

Based on daily observation data at 222 meteorological stations in China,the characteristics of dust storms between 1997 and 2007 were examined.Next,the relationship between dust events and chlorophyll (Chl) a concentration in the Yellow Sea was investigated.There were six regions with high annual frequencies of dust storms.The seasonal distribution of dust storms showed spatiotemporal variation.The six regions with highest annual frequencies also exhibited high frequencies of dust storms in spring.Dust storms in most regions occurred in spring.Of all dust storms in China,sixty-five percent of all dust storms occurred during the spring.The area and frequency of dust storms were smaller in fall and winter than in spring and summer.A significant correlation was found between dust events and Chl a concentration in the Yellow Sea.High correlation regions included Qinghai-Xizang region,part of the Hexi Corridor,the western Inner Mongolia and Hetao Regions,and the Hunshandake Desert.The high correlation may be induced by the high ratio of dust storms in the abovementioned regions that arrive over the Yellow Sea,as inferred through a forward trajectory analysis;especially notable is dust transported at a lower altitude (< 3 km).

How relevant are engineering samples in the management of personal dust exposure?

A directive, legislated by the South African Department of Minerals and Energy(DME) in 1997, was introduced to reduce the dust exposures of continuous miner(CM) operators to below 5 mg/m3, when measured at the operator's cab position. The focus of this paper is to review the effectiveness of observing this rule for almost two decades and discuss industry perceptions arising from the application of this rule. The results have demonstrated that the engineering sample cannot predict the personal shift dust exposure of a CM operator. Therefore, it is recommended that the engineering sampling, as currently practiced,should be reviewed with the objective to discontinue and replace it by the approved PDM3700 realtime dust monitor.

Two Different Dust Storms in Northeast China:the Sources and Influences in East Asia

There are two different dust storms in Northeast China, normal dust and alkali dust, from Kerqin sand land and Songnen saline land. As well as visible damages of the dust storms, there are some invisible influences. The authors provide evidences that the bacteria carried by dusts from remote area should not be ignored, but the damages of the alkali dusts are still not clear.

Aerosol Data Assimilation Using Data from Fengyun-3A and MODIS:Application to a Dust Storm over East Asia in 2011

Aerosol optical depth （AOD） is the most basic paxalneter that describes the optical properties of atmospheric aerosols, and it can be used to indicate aerosol content. In this study, we assimilated AOD data from the Fengyun-3A （FY-3A） and MODIS meteorological satellite using the Gridpoint Statistical Interpolation three-dimensional variational data assimilation system. Experiments were conducted for a dust storm over East Asia in April 2011. Each 0600 UTC analysis initialized a 24-h Weather Research and Forecasting with Chemistry model forecast. The results generally showed that the assimilation of satellite AOD observational data can significantly improve model aerosol mass prediction skills. The AOD distribution of the analysis field was closer to the observations of the satellite after assimilation of satellite AOD data. In addition, the analysis resulting from the experiment assimilating both FY-3A/MERSI （Medium-resolution Spectral Imager） AOD data and MODIS AOD data had closer agreement with the ground-based values than the individual assimilation of the two datasets for the dust storm over East Asia. These results suggest that the Chinese FY-3A satellite aerosol products can be effectively applied to numerical models and dust weather analysis.

The digital diagrams analysis and forecast of sandstorm weather

The strong sandstorm weather process analysis has been done with the information digital diagrams method and times extended observation information on 23rd May,2004 in Gansu Province. The research results reveal the unique mechanism structure of sandstorm disaster weather and the signification of irregular information,approve that the region digital diagrams has the capability to forecast the character and intension of transition disaster weather,and explain certainly that the meteorological problem is transformation problem of evolvement science.

A Case Study of a Typical Dust Storm Event over the Loess Plateau of Northwest China

Enhanced observational meteorological elements,energy fluxes,and the concentration of dust aerosols collected from the Semi-Arid Climate Observatory and Laboratory(SACOL) during a typical dust storm period in March 2010 at Lanzhou were used in this paper to investigate the impact of dust aerosols on near surface atmospheric variables and energy budgets.The results show that the entire dust storm event was associated with high wind velocities and decreasing air pressure,and the air changed from cold and wet to warm and dry and then recovered to its initial state.The response of energy fluxes occurred behind meteorological elements.At high dust concentration periods,the net radiation was significantly less in the daytime and higher at night,while the heat fluxes displayed the same trend,indicating the weakening of the land-atmosphere energy exchange.The results can be used to provide verification for numerical model results in semi-arid areas.

Evaluation of Natural Radioactivity in Dust Storms Samples from AI-Najaf//Iraq

Abstract： 40K, 238U and 232Th in dust storms samples from AI-Najaf Holy Area - lraq in year 2013 were measured using a high efficiency gamma ray spectroscopy NaI（Tl） detector. From the measured gamma rays spectra, the specific activity were determined for 40K （range from 237.166 to 368.689 Bq/kg）, 23SU （range from 11.531 to 34.997 Bq/kg） and 232Th （range from 2.805 to 11.162 Bq/kg）. Hazard indices （external hazard index, internal hazard index, radium equivalent activities and absorbed effective dose rates） were calculated for the measured samples to assess the radiation hazards arising from dust storms samples, which is the average of Hazard indices equal （0.214, 0.192, 25.359 nG/y and 50.855 Bq/Kg）, respectively. All results of Hazard indices were compared with safe limit values recommended by UNSCEAR （2008） below the safe limit.

Global influenza in cold phase of Pacific Decade Oscillation

Based on the study of the cold phase of the Pacific Decade Oscillation, pandemic influenza is related to climate. The relation of low temperature, Pacific Decade Oscillation, strongest earthquake, Influenza, hurricane and E1 Nino is researched in this study. In the cold period of Pacific Decade Oscillation, the strongest earthquake, hurricane with La Ni＇na, Pandemic Influenza with E1 Nino will occur stronger and stronger. From 1950 to 1976, the strongest dust-storm is connected with Pandemic Influenza one by one. So, dust-storm is one of factors to spread pandemic influenza viruses.

Effect of Sand and Dust Storms on Microwave Propagation Signals in Southern Libya

The propagation of electromagnetic waves in millimeter band is severely affected by rain, and dust particles in terms of attenuation and de-polarization. The computations of dust and/or sand storms require knowledge of electrical properties of the scattering particles and climate conditions at the studied region. To compute the effect of dust and sand particles on the propagation of electromagnetic waves, it is required to collect the sand particles carried out by the wind, measure the particles size, calculate the concentration, and carry chemical analysis of the contents, then the dielectric constant can be calculated. The main object of this paper is to study the effect of sand and dust storms on wireless communication, such as microwave links, in the southern region of Libya （Sebha, Ashati, Obari, Morzok, Ghat） by determining the attenuation. The result showed that there is some consideration that has to be taken into account in the communication power budget.

Urban Boundary-Layer Stability and Turbulent Exchange during Consecutive Episodes of Particle Air Pollution in Beijing,China

Based on measurements at the Beijing 325-m Meteorological Tower,this study reports an analysis of atmospheric stability conditions and turbulent exchange during consecutive episodes of particle air pollution in Beijing(China),primarily due to haze and dust events(15–30 April 2012).Of particular interest were relevant vertical variations within the lower urban boundary layer(UBL).First,the haze and dust events were characterized by different atmospheric conditions,as quite low wind speed and high humidity are typically observed during haze events.In addition,for the description of stability conditions,the bulk Richardson number(RiB) was calculated for three different height intervals: 8–47,47–140,and 140–280 m.The values of RiB indicated an apparent increase in the occurrence frequency of stably-stratified air layers in the upper height interval—for the 140–280-m height interval,positive values of RiB occurred for about 85% of the time.The downward turbulent exchange of sensible heat was observed at 280 m for the full diurnal cycle,which,by contrast,was rarely seen at 140 m during daytime.These results reinforce the importance of implementing high-resolution UBL profile observations and addressing issues related to stably-stratified flows.

Holocene dust storm variations over northern China:transition from a natural forcing to an anthropogenic forcing

Asian dust storms have long been a major environmental concern in China,affecting the lives of about one billion people.However,it is unclear whether the mechanisms responsible for Asian dust storms during the Holocene varied on different timescales,and thus it is unclear whether there was a shift from a natural forcing to an anthropogenic forcing of dust storms.We reconstructed a high-resolution Holocene record of dust storms from the sediments of an undisturbed alpine lake on the Chinese Loess Plateau.We found that Asian dust storm activity generally increased during the Holocene,with the largest fluctuations occurring during the past 2000 years.The increase in dust storm activity was in contrast to the decrease in East Asian winter monsoon(EAWM)intensity during the Holocene,indicating that the EAWM played a limited role in modulating dust storms.By contrast,the increase in dust storms corresponded to a decrease in East Asian summer monsoon(EASM)precipitation.This demonstrates that EASM precipitation was the dominant control of dust storm activity on a millennial timescale,because decreased EASM precipitation expanded the desert area and thus increased the dust storm activity.The increasing intensity of human activity in the region since the Bronze Age resulted in an acceleration of dust storm activity against the background of decreased EASM precipitation.As human disturbance continued to intensify,beginning at least at~2 cal ka BP,increased dust storms were closely linked to increasing human populations in the dust source regions,and there is a strong temporal coherence between increased dust storms and higher EASM precipitation.This was completely different from when natural processes are dominant.During that period,fewer dust storms occurred during periods of a strengthened EASM.Therefore,there was a shift from a natural forcing to an anthropogenic forcing of dust storms on a multi-decadal to centennial timescale,and was a mode in which‘‘human activity overtook the EASM as the dominant control of the Earth surface system”.