scholarly journals Asian Dust properties investigated by multi-instruments

2019 ◽  
Vol 99 ◽  
pp. 02003
Author(s):  
Janbai Nee
Keyword(s):  
Remote Sensing ◽  
Dust Cloud ◽  
Asian Dust ◽  
Dust Storms ◽  
Dust Particles ◽  
Atmospheric Processes ◽  
Aerosol Sources ◽  
Dust Events ◽  
Aerosol Cloud Interactions ◽  
Lidar Observations

Dust and many types of aerosols are major pollutants significantly affecting the environment in the East Asia. To identify and classify various types of aerosols is a challenge. In Taiwan and nearby areas, Asian Dust mainly arrive in spring with an average of about 5 dust storms each year. They usually come with some other aerosol sources, therefore it is important to identify these aerosols and their properties. In this paper, we report studying of dust aerosols by using several ground-based and remote sensing measurements. The AERONET data is used to find optical properties of aerosols in 2008-2012. The lidar observations can investigate further properties and atmospheric processes for specific dust events, including observations of aerosol-cloud interactions. These combined with model or space observations can help us to understand long range dust particles transported to distant areas and their interaction with weather systems. A real time case of observation of dust-cloud interaction is provided.

scholarly journals Effects of three-dimensional electric field on saltation during dust storms: An observational and numerical study

2019 ◽  
Author(s):  
Huan Zhang ◽  
You-He Zhou
Keyword(s):  
Electric Field ◽  
Field Data ◽  
Numerical Study ◽  
Three Dimensional ◽  
Vertical Component ◽  
Dust Storms ◽  
Dust Particles ◽  
Sand Transport ◽  
Dust Transport ◽  
Dust Events

Abstract. Particle tribo-electrification being ubiquitous in nature and industry, potentially plays a key role in dust events, including the lifting and transport of sand and dust particles. However, the properties of electric field (E-field) and its influences on saltation during dust storms remain obscure as the high complexity of dust storms and the existing numerical studies mainly limited to one-dimensional (1-D) E-field. Here, we quantify the effects of real three-dimensional (3-D) E-field on saltation, through a combination of field observations and numerical modelling. The 3-D E-fields in the sub-meter layer from 0.05 to 0.7 m above the ground during a dust storm are measured at Qingtu Lake Observation Array site. The measured results show that each component of the 3-D E-field data nearly collapses on a single 3-order polynomial curve when normalized. Interestingly, the vertical component of the 3-D E-field increases with increasing height in the saltation layer during dust storms. Such 3-D E-field data close to the ground within a few centimeters has never been reported and formulated before. Using the discrete element method, we then develop a comprehensive saltation model, in which the tribo-electrification between particle-particle midair collisions is explicitly accounted for, allowing us to evaluate the tribo-electrification in saltation properly. By combining the results of measurements and modelling, we find that although the vertical component of the E-field (i.e. 1-D E-field) inhibits sand transport, 3-D E-field enhances sand transport substantially. Furthermore, the model predicts that 3-D E-field enhances the total mass flux by up to 63 %. This suggests that a truly 3-D E-field consideration is necessary if one is to explain precisely how the E-field affects saltation during dust storms. These results will further improve our understanding of particle tribo-electrification in saltation and help to provide more accurate characterizations of sand and dust transport during dust storms.

scholarly journals Size-resolved atmospheric ice-nucleating particles during East Asian dust events

2021 ◽  
Vol 21 (5) ◽  
pp. 3491-3506
Author(s):  
Jingchuan Chen ◽  
Zhijun Wu ◽  
Jie Chen ◽  
Naama Reicher ◽  
Xin Fang ◽  
...  
Keyword(s):  
Particle Size ◽  
Mineral Dust ◽  
East Asian ◽  
Substantial Effect ◽  
Ice Nucleation ◽  
Asian Dust ◽  
Dust Particles ◽  
Significant Difference ◽  
Dust Events ◽  
Surface Ice

Abstract. Asian dust is an important source of atmospheric ice-nucleating particles (INPs). However, the freezing activity of airborne Asian dust, especially its sensitivity to particle size, is poorly understood. In this study we report the first INP measurement of size-resolved airborne mineral dust collected during East Asian dust events. The measured total INP concentrations in the immersion mode ranged from 10−2 to 102 L−1 in dust events at temperatures between −25 and −5 ∘C. The average contributions of heat-sensitive INPs at three temperatures, −10, −15, and −20 ∘C, were 81±12 %, 70±15 %, and 38±21 %, respectively, suggesting that proteinaceous biological materials have a substantial effect on the ice nucleation properties of Asian airborne mineral dust at high temperatures. The dust particles which originated from China's northwest deserts are more efficient INPs compared to those from northern regions. In general, there was no significant difference in the ice nucleation properties between East Asian dust particles and other regions in the world. An explicit size dependence of both INP concentration and surface ice-active-site density was observed. The nucleation efficiency of dust particles increased with increasing particle size, while the INP concentration first increased rapidly and then leveled, due to the significant decrease in the number concentration of larger particles. A new set of parameterizations for INP activity based on size-resolved nucleation properties of Asian mineral dust particles were developed over an extended temperature range (−35 to −6 ∘C). These size-dependent parameterizations require only particle size distribution as input and can be easily applied in models.

scholarly journals TEM analysis of the internal structures and mineralogy of Asian dust particles and the implications for optical modeling

2014 ◽  
Vol 14 (5) ◽  
pp. 6619-6661 ◽  
Author(s):  
G. Y. Jeong ◽  
T. Nousiainen
Keyword(s):  
Remote Sensing ◽  
Internal Structure ◽  
Mineral Composition ◽  
Radiation Effects ◽  
Mineral Dust ◽  
Ion Beam ◽  
Single Scattering ◽  
Asian Dust ◽  
Dust Particles ◽  
Internal Structures

Abstract. Mineral dust interacts with incoming/outgoing electromagnetic radiation in the atmosphere. This interaction depends on the microphysical properties of the dust particles, including size, mineral composition, external morphology, and internal structure. Ideally all these properties should be accounted for in dust remote sensing, the modeling of single-scattering properties, and radiative effect assessment. There have been many reports on the microphysical characterizations of mineral dust, but no investigations of the internal structures or mineral composition of individual dust particles. We explored the interiors of Asian dust particles using the combined application of focused ion beam thin-slice preparation and high-resolution transmission electron microscopy. The results showed that individual dust particles consisted of numerous mineral grains, which were organized into several types of internal structure: single and polycrystalline cores of quartz, feldspars, calcite, and amphibole often with oriented clay coatings; individual clay agglomerates of nano-thin clay platelets showing preferred to random orientations commonly with coarser mineral inclusions; and platy coarse phyllosilicates (muscovite, biotite, and chlorite). Micron to submicron pores were scattered throughout the interior of particles. Clays in the coatings and agglomerates were dominated by nano-thin platelets of the clay minerals of illite-smectite series including illite, smectite, and their mixed layers with subordinate kaolinite and clay-size chlorite. Submicron iron oxide grains, dominantly goethite, were distributed throughout the clay agglomerates and coatings. Unlike the common assumptions and simplifications, we found that the analyzed dust particles were irregularly shaped with birefringent, polycrystalline, and polymineralic heterogeneous compositions. Accounting for this structural and mineralogical makeup may improve the remote sensing retrieval of dust and the evaluation of radiation effects, but will also require sophisticated single-scattering modeling. In particular, the observed internal structures of dust particles such as clay coatings, preferred orientation, embedded grains in clays, and pores, likely have a great impact on the light scattering of dust particles. The distribution and size of structural components with contrasting dielectric properties, such as iron oxides, should also be explicitly accounted for.

scholarly journals A comprehensive characterisation of Asian dust storm particles: chemical composition, reactivity to SO<sub>2</sub>, and hygroscopic property

2010 ◽  
Vol 10 (4) ◽  
pp. 8899-8925 ◽  
Author(s):  
Q. Ma ◽  
Y. Liu ◽  
C. Liu ◽  
J. Ma ◽  
H. He
Keyword(s):  
Dust Storm ◽  
Heterogeneous Reaction ◽  
Cell Mass ◽  
Asian Dust ◽  
Dust Storms ◽  
Source Distribution ◽  
Dust Particles ◽  
Uptake Coefficient ◽  
Asian Dust Storm ◽  
The Impact

Abstract. Mineral dust comprises of a significant fraction of the globe's aerosol loading. Yet it remains the largest uncertainty in future climate predictions due to the complexity in its components and physico-chemical properties. Multi-analysis methods, including SEM-EDX, FTIR, BET, TPD/mass, and Knudsen cell/mass, were used in the present study to characterise Asian dust storm particles. The morphology, element fraction, source distribution, true uptake coefficient of SO2 and hygroscopic behaviour were studied. The major components of Asian dust storm particles were found to consist of aluminosilicate, SiO2, and CaCO3, which were coated with organic compounds and inorganic nitrate. The dust storm particles have a low reactivity to SO2 (true uptake coefficient of 5.767×10−6) which limits the conversion of SO2 to sulfate during a dust storm period. The low reactivity also demonstrated that the heterogeneous reaction of SO2, in both dry and humid air conditions, had little effect on the hygroscopic behaviour of the dust particles. These results indicate that the impact of dust storms on atmospheric SO2 removal should not be overestimated.

scholarly journals Size-Resolved Atmospheric Ice Nucleating Particles during East Asian Dust Events

2020 ◽  
Author(s):  
Jingchuan Chen ◽  
Zhijun Wu ◽  
Jie Chen ◽  
Naama Reicher ◽  
Xin Fang ◽  
...  
Keyword(s):  
Particle Size ◽  
Mineral Dust ◽  
East Asian ◽  
Substantial Effect ◽  
Ice Nucleation ◽  
Asian Dust ◽  
Dust Particles ◽  
Significant Difference ◽  
Dust Events ◽  
Surface Ice

Abstract. Asian dust is an important source of atmospheric ice nucleating particles (INPs). However, the freezing activity of airborne Asian dust, especially its sensitivity to particle size, is poorly understood. In this study we report the first INP measurement of size-resolved airborne mineral dust collected during East Asian dust events. The measured total INP concentrations in the immersion mode ranged from 10−2 to 102 L−1 in dust events at temperatures between −25 and −5 °C. The average contributions of heat-sensitive INPs at three temperatures, −10, −15, and −20 °C, were 81 ± 12 %, 70 ± 15 %, and 38 ± 21 %, respectively, suggesting that proteinaceous biological materials have a substantial effect on the ice nucleation properties of Asian atmospheric mineral dust at warm temperatures. The dust particles which originated from China's northwest deserts are more efficient INPs compared to those from northern regions. There was no significant difference in the ice nucleation properties between East Asian dust particles and other regions in the world. An explicit size dependence of both INP concentration and surface ice active density was observed. The nucleation efficiency of dust particles increased with increasing particle size, while the INP concentration first increased rapidly and then levelled, due to the significant decrease in the number concentration of larger particles. A new set of parameterizations for INP activity based on size-resolved nucleation properties of Asian mineral dust particles were developed over an extended temperature range (−35 ~ −6 °C). These size-dependent parameterizations require only particle size distributions as input, and can be easily applied in models.

scholarly journals Interplanetary Dust Close to the Sun

1991 ◽  
Vol 126 ◽  
pp. 187-190
Author(s):  
Ingrid Mann
Keyword(s):  
Remote Sensing ◽  
Thermal Emission ◽  
Dust Cloud ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
The Sun ◽  
Zodiacal Dust ◽  
In Situ Experiments ◽  
Infrared Brightness

AbstractThe optical and infrared brightness of the Fraunhofer-corona is produced by light scattering at the zodiacal dust particles and by their thermal emission (see Koutchmy and Lamy 1985). It is modelled within the ecliptic (4 Ro≤ ε ≤ 15 Ro)taking into account investigations of the global zodiacal dust cloud due to remote sensing and in situ experiments. The input of near solar dust to the corona brightness is discussed.

scholarly journals Long-range transported bioaerosols captured in snow cover on Mount Tateyama, Japan: Impacts of Asian-dust events on airborne bacterial dynamics relating to ice-nucleation activities

2018 ◽  
Author(s):  
Teruya Maki ◽  
Shogo Furumoto ◽  
Yuya Asahi ◽  
Kevin C. Lee ◽  
Koichi Watanabe ◽  
...  
Keyword(s):  
Snow Cover ◽  
Long Range ◽  
Bacterial Communities ◽  
Aerosol Particles ◽  
Ice Nucleation ◽  
Asian Dust ◽  
Dust Particles ◽  
Bacterial Dynamics ◽  
Dust Events ◽  
Snow Samples

Abstract. The westerly wind travelling at high altitudes over East Asia transports aerosols from the Asian deserts and urban areas to downwind areas such as Japan. These long-range transported aerosols include not only mineral particles, but also microbial particles (bioaerosols), that impact the ice-cloud formation processes as ice nuclei. However, the the detailed relations of airborne bacterial dynamics to ice nucleation in high-elevation aerosols have not been investigated. Here, we used the aerosol particles captured in the snow cover at the altitudes of 2450 m on Mt. Tateyama to investigate the sequential changes of ice-nucleation activities and bacterial communities in aerosols and elucidate the relationships between the two processes. After stratification of the snow layers formed on the walls of a snow pit on Mt. Tateyama, snow samples, including aerosol particles, were collected from 70 layers at the lower (winter accumulation) and upper (spring accumulation) parts of the snow wall. The aerosols recorded in the lower parts mainly came from Siberia (Russia), North Asia, and the Sea of Japan, while those in the upper parts showed an increase the Asian-dust particles, which originate from the desert regions and industrial coasts of Asian. The snow samples exhibited high levels of ice nucleation corresponding to the increase of Asian dust particles. Amplicon sequencing analysis using 16S rRNA genes revealed that the bacterial communities in the snow samples predominately included plant associated and marine bacteria (phyla Proteobacteria) during winter; whereas, during spring, when dust events arrived frequently, the majority were terrestrial bacteria of phyla Actinobacteria and Firmicutes. The relative abundances of Firmicutes (Bacilli) showed a significant positive relationship to the ice nucleation in snow samples. Presumably, Asian dust events change the airborne bacterial communities over Mt. Tateyama and carry terrestrial bacterial populations, which possibly induce ice-nucleation activities, thereby indirectly effecting on climate changes.

scholarly journals Analysis of Persian Oak (Quercus Brantii Lindl)’s Spectral- Temporal Behaviour Under the Stresses of Water Deficiency and Dust Particles

2019 ◽  
Vol 99 ◽  
pp. 04011
Author(s):  
Ali Darvishi Boloorani ◽  
Soghra Ranjbareslamloo ◽  
Saham Mirzaie ◽  
Hossein Ali Bahrami ◽  
Fardin Mirzapour ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Stress ◽  
Dust Storms ◽  
Dust Particles ◽  
Tree Seedlings ◽  
Mountain Range ◽  
Water Deficiency ◽  
Remote Sensing Images ◽  
Temporal Behaviour ◽  
Quercus Brantii

Persian oak (Quercus Brantii Lindl) is the most abundant tree species in Zagros mountain range that is affected by western dust storms and harsh droughts in recent years. The lack of spectral-temporal information about these trees has caused limitations on the usage of remote sensing images to make a synoptic estimation of damages caused by dust storms and drought. The objective of this research is to analyse the spectral-temporal behaviour of Persian oak under the stress of water deficiency and dust storms. The aim is to improve the competitive abilities of experts on modelling the stress of water deficiency and dust storms on trees using remote sensing images. For the purpose of this experimental investigation, a greenhouse laboratory has been built. Analysis of the experiments was carried out using 54 two-year-old oak tree seedlings; Fieldspec-3-ADD; and wind tunnel at the greenhouse of the faculty of agriculture of the Tarbiat Modares University in 2016. Results show that the water stress could be modelled much better using geometrical indices extracted from continuum removed spectrum. Area and the depth were best indices. Water stress has been modelled better that dust stress.

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