Influence of chemical aging on physico-chemical properties of mineral dust particles: A case study of 2016 dust storms over Delhi

2020 ◽  
Vol 267 ◽  
pp. 115338
Author(s):  
Vikas Goel ◽  
Sumit K. Mishra ◽  
Prabir Pal ◽  
Ajit Ahlawat ◽  
Narayanasamy Vijayan ◽  
...  
Keyword(s):  
Mineral Dust ◽  
Chemical Properties ◽  
Dust Storms ◽  
Dust Particles ◽  
Chemical Aging ◽  
Physico Chemical

scholarly journals Feedback between dust particles and atmospheric processes over West Africa during dust episodes in March 2006 and June 2007

2010 ◽  
Vol 10 (22) ◽  
pp. 10771-10788 ◽  
Author(s):  
T. Stanelle ◽  
B. Vogel ◽  
H. Vogel ◽  
D. Bäumer ◽  
C. Kottmeier
Keyword(s):  
West Africa ◽  
Mineral Dust ◽  
Dust Storms ◽  
Dust Particles ◽  
Total Emission ◽  
Radiative Effect ◽  
Radiative Fluxes ◽  
Dust Layer ◽  
Emission Fluxes ◽  
The Impact

Abstract. We used the comprehensive model system COSMO-ART to quantify the impact of mineral dust on the radiative fluxes, the temperature and the feedback between dust particles and their emissions. We simulated two dust storms over West Africa in March 2006 and in June 2007. Simulations with and without coupling of the actual dust concentration with the radiative fluxes and the thermodynamics were carried out for each case. The model results for the 2006 case were compared with observations of the AMMA campaign. At the surface the shortwave radiative effect of mineral dust can be described by a linear relation between the changes in net surface radiation and the aerosol optical depth (AOD). For an AOD at 450 nm of 1 the average shortwave radiation reduction amounts −140 W m−2 during noon. The longwave radiative effect of mineral dust is nonlinear, with an average increase of +70 W m−2 for an AOD (450 nm) of 1. At the top of the atmosphere the effect of the dust layer with an AOD of 1 on radiative fluxes is not as significant as at the surface. It is slightly positive for the shortwave and approximately 26 W m−2 for the longwave radiation. The height range and the extension of the dust layer determine the effect of dust particles on the 2 m temperature. When the dust layer is attached to the surface and lasts for several days it leads to an increase of the surface temperature even during daytime. In case of an elevated dust layer there is a decrease in 2 m temperature of up to 4 K during noon. It is shown, that the temperature changes caused by mineral dust may result in horizontal temperature gradients which also modify near surface winds. Since surface wind thresholds decide the uptake of dust from the surface, a feedback on total emission fluxes is established. The coupled model provides an increase in the total emission fluxes of dust particles by about 16% during the dust storm in March 2006 and 25% during the dust episode in June 2007.

Tropospheric Mineral Dust Study by High Spectral Resolution Infrared Satellite during intense dust storms

2021 ◽  
Author(s):  
Perla Alalam ◽  
Hervé Herbin
Keyword(s):  
Mineral Dust ◽  
Complex Refractive Index ◽  
Estimation Method ◽  
Dust Storms ◽  
High Spectral Resolution ◽  
Dust Particles ◽  
Physical Parameters ◽  
Chemical Compositions ◽  
Storm Events ◽  
Atmospheric Measurements

<p>Large desert lands such as Sahara, Gobi or Australia present main sources of atmospheric mineral dust caused by intense dust storms. Transported dust particles undergo physical and chemical changes affecting their microphysical and optical properties. This modifies their scattering and absorption properties and alters the global atmospheric radiative budget.</p><p>Currently, remote sensing techniques represent a powerful tool for quantitative atmospheric measurements and the only means of analyzing its evolution from local to global scale. In order to improve the knowledge of atmospheric aerosol distributions, many efforts were made particularly in the development of hyperspectral infrared spectrometers and processing algorithms. However, to fully exploit these measurements, a perfect knowledge of Complex Refractive Index (CRI) is required.</p><p>In that purpose, a new methodology <sup></sup>based on laboratory measurements of mineral dust in suspension coupled with an optimal estimation method has been developed. This approach allows getting access to CRI of several desert samples with various chemical compositions.</p><p>Here, we present the first results of the physical parameters (effective radius and concentration) retrievals using Infrared Atmospheric Sounding Interferometer IASI data, during dust storm events. The latter use the CRI of different desert samples obtained in laboratory and a new radiative transfer algorithm (ARAHMIS) developed at Laboratoire d’Optique Atmosphérique LOA.</p>

Seedball-induced changes of root growth and physico-chemical properties-a case study with pearl millet

2018 ◽  
Vol 181 (5) ◽  
pp. 768-776 ◽  
Author(s):  
Charles I. Nwankwo ◽  
Sebastian R. G. A. Blaser ◽  
Doris Vetterlein ◽  
Günter Neumann ◽  
Ludger Herrmann
Keyword(s):  
Root Growth ◽  
Pearl Millet ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Induced Changes

scholarly journals COST Lecture 2019 AE GM Barcelona: International Network to Encourage the Use of Monitoring and Forecasting Dust Products (InDust)

2020 ◽  
pp. 1-15
Author(s):  
Anca Nemuc ◽  
Sara Basart ◽  
Aurelio Tobias ◽  
Slobodan Nickovic ◽  
Francesca Barnaba ◽  
...  
Keyword(s):  
Service Providers ◽  
Mineral Dust ◽  
Dust Storms ◽  
Dust Particles ◽  
Economic Sectors ◽  
International Network ◽  
Airborne Dust ◽  
Monitoring And Forecasting ◽  
High Concentrations ◽  
Research Networking

Amongst the most significant extreme meteorological phenomena are the Sand and Dust Storms (SDS). Owing to significant amounts of airborne mineral dust particles generated during these events, SDS have impacts on climate, the environment, human health, and many socio-economic sectors (e.g. aviation, solar energy management). Many studies and reports have underlined that the society has to understand, manage and mitigate the risks and effects of SDS on life, health, property, the environment and the economy in a more unified way. The EU-funded European Cooperation in Science and Technology (COST) Action ‘InDust: International network to encourage the use of monitoring and forecasting Dust products’ has an overall objective to establish a network involving research institutions, service providers and potential end users on airborne dust information. We are a multidisciplinary group of international experts on aerosol measurements, aerosol modelling, stakeholders and social scientists working together, exchanging ideas to better coordinate and harmonize the process of transferring dust observation and prediction data to users, as well as to assist the diverse socio-economic sectors affected by the presence of high concentrations of airborne mineral dust. This article highlights the importance of being actively engaged in research networking activities, supported by EU and COST actions since common efforts help not only each scientist by shaping their expertise and strengthening their position, but also all communities.

A comparative evaluation of water uptake on several mineral dust sources

2010 ◽  
Vol 7 (2) ◽  
pp. 162 ◽  
Author(s):  
Juan G. Navea ◽  
Haihan Chen ◽  
Min Huang ◽  
Gregory R. Carmichel ◽  
Vicki H. Grassian
Keyword(s):  
Chemical Composition ◽  
Relative Humidity ◽  
Dust Particle ◽  
Water Uptake ◽  
Mineral Dust ◽  
Dust Storms ◽  
Dust Aerosol ◽  
Dust Particles ◽  
Particle Interactions ◽  
Dust Sources

Environmental context. Dust particles produced from wind blown soils are of global significance as these dust particles not only impact visibility, as evident in the recent 2009 Australian dust storm, but also atmospheric chemistry, climate and biogeochemical cycles. The amount of water vapour in the atmosphere (relative humidity) can play a role in these global processes yet there are few studies and little quantitative data on water-dust particle interactions. The focus of this research is on quantifying water-dust particle interactions for several dust sources including Asia and Africa where dust storms are most prevalent. Abstract. Mineral dust aerosol provides a reactive surface in the troposphere. The reactivity of mineral dust depends on the source region as chemical composition and mineralogy of the aerosol affects its interaction with atmospheric gases. Furthermore, the impact of mineral dust aerosol in atmospheric processes and climate is a function of relative humidity. In this study, we have investigated water uptake of complex dust samples. In particular, water uptake as a function of relative humidity has been measured on three different dust sources that have been characterised using a variety of bulk and surface techniques. For these well-characterised dust samples, it is shown that although there are variations in chemical composition and mineralogy, on a per mass basis, water uptake capacities for the three dusts are very similar and are comparable to single component clay samples. These results suggest that the measured uptake of water of these bulk samples is dominated by the clay component.

scholarly journals Impacts of long-range-transported mineral dust on summertime convective cloud and precipitation: a case study over the Taiwan region

2021 ◽  
Vol 21 (23) ◽  
pp. 17433-17451
Author(s):  
Yanda Zhang ◽  
Fangqun Yu ◽  
Gan Luo ◽  
Jiwen Fan ◽  
Shuai Liu
Keyword(s):  
Long Range ◽  
Transport Model ◽  
Mineral Dust ◽  
Convective Cloud ◽  
Dust Particles ◽  
Chemical Transport Model ◽  
Dust Aerosols ◽  
Convective Clouds ◽  
Water Contents

Abstract. As one of the most abundant atmospheric aerosols and effective ice nuclei, mineral dust affects clouds and precipitation in the Earth system. Here numerical experiments are carried out to investigate the impacts of dust aerosols on summertime convective clouds and precipitation over the mountainous region of Taiwan by acting as ice-nucleating particles. We run the Weather Research and Forecasting model (WRF) with the Morrison two-moment and spectral-bin microphysics (SBM) schemes at 3 km resolution, using dust number concentrations from a global chemical transport model (GEOS-Chem-APM). The case study indicates that the long-range-transported mineral dust, with relatively low number concentrations, can notably affect the properties of convective clouds (ice and liquid water contents, cloud top height, and cloud coverage) and precipitation (spatial pattern and intensity). The effects of dust are evident during strong convective periods, with significantly increased ice water contents in the mixed-phase regime via the enhanced heterogeneous freezing. With both the Morrison and SBM schemes, we see the invigoration effects of dust aerosols on the convective intensity through enhanced condensation and deposition latent heating. The low-altitude dust particles are uplifted to the freezing level by updrafts, which, in turn, enhance the convective cloud development through immersion freezing and convective invigoration. Compared to the Morrison scheme, the SBM scheme predicts more realistic precipitation and different invigoration effects of dust. The differences are partially attributed to the saturation adjustment approach utilized in the bulk scheme, which leads to a stronger enhancement of condensation at midlatitudes to low altitudes and a weaker deposition increase at the upper level.

scholarly journals The risk of liquid wood degradation under the influence of marine factors

2019 ◽  
Vol 290 ◽  
pp. 12012
Author(s):  
Mihaela Luminita Barhalescu ◽  
Simona Ghita ◽  
Tudor-Cristian Petrescu
Keyword(s):  
Electric Conductivity ◽  
Renewable Resources ◽  
Chemical Properties ◽  
External Factors ◽  
Wood Degradation ◽  
Biofilm Growth ◽  
Physico Chemical ◽  
Starting Point ◽  
Biocomposite Material

A case study was performed, concerning the behavior and degradation of a polymeric biocomposite material – “liquid wood”. This material is biodegradable and it is obtained from renewable resources. Three presentation forms – Arbofill Fichte, Arboform F45 and Arboblend V2, were subjected to the action of external factors present in a marine environment. The results pertaining to the change in the physico – chemical properties of “liquid wood” when subjected to the action of seawater and seawater microorganisms, with significant – but nevertheless positive – consequences upon the environment. The material exhibits good performance after the surface and mass stabilization – due to water, C, Na, Cl and O absorption. As such – due to the emergence of a protective organic biofilm – growth of microorganisms significantly decreases and electric conductivity increases. This case study may be viewed as a starting point for subsequent studies of “liquid wood”.

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