The objective of this study was to characterize the mass concentration and chemical composition of aerosol particles（PM2.5） collected at Tongliao（Inner Mongolia Autonomous Region, China）, a site in Horqin Sand-lan...The objective of this study was to characterize the mass concentration and chemical composition of aerosol particles（PM2.5） collected at Tongliao（Inner Mongolia Autonomous Region, China）, a site in Horqin Sand-land in northeast China. During spring 2005, the mass concentration for PM2.5 was （126±71）μg/m^3 in average. Five dust storm events were monitored with higher concentration of （255 ± 77）μg/m^3 in average than the non dusty days of （106 ± 44）μg/m^3. Concentrations for 20 elements were obtained by the PIXE method. Mass concentrations of ALl, Mg, Si, K, Ca, Ti, Mn, and V, which increased with the PM2.5 concentration, were higher than the pollution elements （S, Cl, Zn, Ar, Se, Br, and Pb）. Enrichment factor relative to crust material was also calculated, which showed dust trace elements were mainly from earth upper crust and pollution elements were dominated the anthropogenic aerosols. The Si/Al, Ca/Al, and Fe/Al ratios in PM2.5 samples at Tongliao were 4.07, 0.94, and 0.82, respectively, which were remarkably different with those on other source regions, such as ＂Western desert source region＂, ＂North desert source region＂ and central Asia source. Air mass back-trajectory analysis identified three kinds of general pathways were associated with the aerosol particle transport to Tongliao, but have the similar elemental ratios, implying that elemental signatures for dust aerosol from Horqin Sand-land were different with other regions.展开更多
Within the context of our current research and understanding of climate change,decisionmakers are particularly concerned with the extent of future climate change,its comprehensive impact,and the types of socioeconomic...Within the context of our current research and understanding of climate change,decisionmakers are particularly concerned with the extent of future climate change,its comprehensive impact,and the types of socioeconomic pathways available with respect to mitigation and adaptation.Among the factors contributing to these important issues,the role of air pollution in global and regional climate warming remains as one of the largest uncertainties.On the basis of understanding of the IPCC Fifth Assessment Report,specifically,in the role of air pollution in climate change,scenarios establishment,and relationship between the Shared Socioeconomic Pathways(SSPs) and Representative Concentration Pathways(RCPs).Weaknesses and reflections were discussed here especially in strengthening impact,adaptation and mitigation research that related with changes in air pollution and climate.In the future,there are needs to in-depth understand how and why the air pollution in China is so serious and changing; to understand the likely future changes in air pollution and climate; to strengthen comprehensive impact research and selective reduction strategies related to changes in air pollution and climate.Furthermore,this study outlines the needs to develop strategies to close the loop of differential impacts and costs; to establish co-benefits and sustainable development goals,to identify the crucial risks and options for synergies/trade-offs; to integrate sector-specific details with macro-economics,and to integrate the assessments of the various policy instruments.All these focus areas will help to facilitate the transition of economic development patterns towards green and low-carbon development.展开更多
Even though the biological crusts are critical to dust emissions,no sand and dust forecast model have considered the impacts of the biological crust in dust emission scheme.This situation mainly comes from two scienti...Even though the biological crusts are critical to dust emissions,no sand and dust forecast model have considered the impacts of the biological crust in dust emission scheme.This situation mainly comes from two scientific difficulties:there is no large scale regional biological crust data available that can be used in the forecast model;there is no quantification of how biological crusts impact on sand emission.In this way,we studied the distribution of biological soil crust in sand and dust storm source areas of Central and East Asia using Moderate Resolution Imaging Spectroradiometer satellite surface reflectance data collected in 2000—2019 to determine its potential impact on dust emission according to two empirical schemes.We further evaluated the relationships between soil crust coverage,roughness length,and dust emission to study SDS source areas.We found that biological crust is widely distributed in SDS source areas of Central and East Asia,with coverage rates of 19.8%in Central Asian deserts,23.1%in the Gobi Desert,and 17.3%—32.8%in Chinese deserts(p>0.05).Cyanobacteria and lichen coverage has increased in Chinese deserts,reflecting the recent impacts of the Project of Returning Farmland to Grassland and Farmland to Forests.However,biological soil crust coverage has not increased in Central Asian deserts or the Gobi Desert,and that in Central Asian deserts continues to decrease,demonstrating the complexity of the combined effects of human activities and climate change on its distribution.Biological soil crust increased the roughness length of Central and East Asian SDS source areas by 0.14—0.62 mm.The suppression of dust emission due to biological soil crust did not change among years during the study period.The horizontal and vertical dust flux inhibition coefficient(DFIC)were 2.0—11.0 and 1.7—2.9(p>0.05),respectively,clearly showing a suppressive effect.Improvement of the ecological environment in some deserts can lead to the ability of these crusts to inhibit dust erosion errors that must be considered in the dust emission scheme for areas where crust coverage has improved.展开更多
文摘The objective of this study was to characterize the mass concentration and chemical composition of aerosol particles（PM2.5） collected at Tongliao（Inner Mongolia Autonomous Region, China）, a site in Horqin Sand-land in northeast China. During spring 2005, the mass concentration for PM2.5 was （126±71）μg/m^3 in average. Five dust storm events were monitored with higher concentration of （255 ± 77）μg/m^3 in average than the non dusty days of （106 ± 44）μg/m^3. Concentrations for 20 elements were obtained by the PIXE method. Mass concentrations of ALl, Mg, Si, K, Ca, Ti, Mn, and V, which increased with the PM2.5 concentration, were higher than the pollution elements （S, Cl, Zn, Ar, Se, Br, and Pb）. Enrichment factor relative to crust material was also calculated, which showed dust trace elements were mainly from earth upper crust and pollution elements were dominated the anthropogenic aerosols. The Si/Al, Ca/Al, and Fe/Al ratios in PM2.5 samples at Tongliao were 4.07, 0.94, and 0.82, respectively, which were remarkably different with those on other source regions, such as ＂Western desert source region＂, ＂North desert source region＂ and central Asia source. Air mass back-trajectory analysis identified three kinds of general pathways were associated with the aerosol particle transport to Tongliao, but have the similar elemental ratios, implying that elemental signatures for dust aerosol from Horqin Sand-land were different with other regions.
基金supported by grants from National Key Project of Basic Research (2011CB403401)
文摘Within the context of our current research and understanding of climate change,decisionmakers are particularly concerned with the extent of future climate change,its comprehensive impact,and the types of socioeconomic pathways available with respect to mitigation and adaptation.Among the factors contributing to these important issues,the role of air pollution in global and regional climate warming remains as one of the largest uncertainties.On the basis of understanding of the IPCC Fifth Assessment Report,specifically,in the role of air pollution in climate change,scenarios establishment,and relationship between the Shared Socioeconomic Pathways(SSPs) and Representative Concentration Pathways(RCPs).Weaknesses and reflections were discussed here especially in strengthening impact,adaptation and mitigation research that related with changes in air pollution and climate.In the future,there are needs to in-depth understand how and why the air pollution in China is so serious and changing; to understand the likely future changes in air pollution and climate; to strengthen comprehensive impact research and selective reduction strategies related to changes in air pollution and climate.Furthermore,this study outlines the needs to develop strategies to close the loop of differential impacts and costs; to establish co-benefits and sustainable development goals,to identify the crucial risks and options for synergies/trade-offs; to integrate sector-specific details with macro-economics,and to integrate the assessments of the various policy instruments.All these focus areas will help to facilitate the transition of economic development patterns towards green and low-carbon development.
基金supported by the National Key Project of the Ministry of Science and Technology of China(2019YFC0214601)Foundation for Development of Science and Technology of Chinese Academy of Meteorological Sciences(2018KJ048,2017Z01).
文摘Even though the biological crusts are critical to dust emissions,no sand and dust forecast model have considered the impacts of the biological crust in dust emission scheme.This situation mainly comes from two scientific difficulties:there is no large scale regional biological crust data available that can be used in the forecast model;there is no quantification of how biological crusts impact on sand emission.In this way,we studied the distribution of biological soil crust in sand and dust storm source areas of Central and East Asia using Moderate Resolution Imaging Spectroradiometer satellite surface reflectance data collected in 2000—2019 to determine its potential impact on dust emission according to two empirical schemes.We further evaluated the relationships between soil crust coverage,roughness length,and dust emission to study SDS source areas.We found that biological crust is widely distributed in SDS source areas of Central and East Asia,with coverage rates of 19.8%in Central Asian deserts,23.1%in the Gobi Desert,and 17.3%—32.8%in Chinese deserts(p>0.05).Cyanobacteria and lichen coverage has increased in Chinese deserts,reflecting the recent impacts of the Project of Returning Farmland to Grassland and Farmland to Forests.However,biological soil crust coverage has not increased in Central Asian deserts or the Gobi Desert,and that in Central Asian deserts continues to decrease,demonstrating the complexity of the combined effects of human activities and climate change on its distribution.Biological soil crust increased the roughness length of Central and East Asian SDS source areas by 0.14—0.62 mm.The suppression of dust emission due to biological soil crust did not change among years during the study period.The horizontal and vertical dust flux inhibition coefficient(DFIC)were 2.0—11.0 and 1.7—2.9(p>0.05),respectively,clearly showing a suppressive effect.Improvement of the ecological environment in some deserts can lead to the ability of these crusts to inhibit dust erosion errors that must be considered in the dust emission scheme for areas where crust coverage has improved.
