Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Chine → 2009 → Characteristics, Source, Long-range Transport of Dust Aerosol over the Central Asia and Its Potential Effect on Global Change

Université Fudan (2009)

Characteristics, Source, Long-range Transport of Dust Aerosol over the Central Asia and Its Potential Effect on Global Change

李娟;

Titre : Characteristics, Source, Long-range Transport of Dust Aerosol over the Central Asia and Its Potential Effect on Global Change

Auteur : 李娟;

Grade : Doctoral Dissertation 2009

Université : Université Fudan

Résumé partiel
Atmospheric aerosol would have tremendous impact on the global environmental andclimate change through influencing radiation,atmospheric chemistry,andcloud/precipitation processes and shifting the balance of the radiation energy andwater cycle.The long-range transport of aerosol has been regarded as the importantpath of the global biogeochemical cycle.The study on the atmospheric aerosol is thestudy on the balance of the global biogeochemical cycling among atmosphere,hydrosphere,biosphere,and human-sphere,which has been of the vital significance tohuman being,and it has been the important domain of the study on the globalenvironmental and climate change.Atmospheric aerosol can travel across over Pacific and Atlantic,and it would exertgreat influence on both the regional environment and the global climate change.Theair pollution has been global issue.Those deserts located in the center of Asia andLoess Plateau is the major sources of those aerosols over Pacific.To investigatedeeply into the temporal and spatial distribution,the physicochemical characteristics,and sources of Asian dust would understand the mechanism of the mixing and theinteraction of mineral with pollution aerosols,which has been the urgent need indeveloping economy and improving the life quality of human being.The major results of this study are as below:1.The physic-chemical characteristics,sources,and the formation mechanism of thedust aerosol from those typical areas of Central Asian Dust as well as theirpossible impact on the regional environment of the downstream urban cities aswell as the global climate change were revealed.The aerosols from Taklimakandesert,one of the two major sources of Asian dust storm,which also is the secondgreat desert over the world,are characterized of high mass concentration,highcontent of sulfur and calcium.It was found that 90% of the sulfur in the aerosolsover Taklimakan desert and in the soil collected from the desert is in the form ofsulfate.Additionally,the sulfate in the aerosols shows a high positive relation withthose ions of sodium,chlorine,and potassium,which indicated evidently thatthose components in the aerosols were from the paleo-marine source.Theseresults were the evidence to support the hypotheses that Taklimakan desert wasused to be the ocean~5.3 millions year ago. 2.It was found that the ratio of Ca/Al in the aerosols over Taklimakan is over 1.5,whereas it is only~0.5 in Gobi located in Mongolia and Inner Mongolia.Thisdistinct difference makes the ratio of Ca/A1 be used as excellent tracer todistinguish the two major source areas of Asian dust and to distinguish the out-citysources of those local urban areas.3.The annual transport of dust from Taklimakan desert is 1.69*107 ton,whichincludes 2.1*105 ton of sulfate and 6.2*104 ton of black carbon.As most ofsulfur in the dust aerosol and soil of Taklimakan was found to be in the form ofsulfate,the amount transported out from this second largest desert would be muchmore than previously estimated.Those sulfate emitted and transported fromTaklimakan desert would have great impact on the regional atmosphericenvironment and the global climate change.4.Urumqi is one of the heavy polluted cities in the world,as the days of hazespanned over one third of the year and accounted for 60-80% of the heating periodfor the past six years.

Mots clés : Asian dust; Aerosol; Characteristics; Source; Long-range transport; Taklimakan Desert;

Présentation (CNKI)

Page publiée le 2 mai 2018