scholarly journals Dust particle size, shape and optical depth during the 2018/MY34 martian global dust storm retrieved by MSL Curiosity rover Navigation Cameras

Icarus ◽  
2021 ◽  
Vol 354 ◽  
pp. 114021
Author(s):  
H. Chen-Chen ◽  
S. Pérez-Hoyos ◽  
A. Sánchez-Lavega
Keyword(s):  
Particle Size ◽  
Dust Particle ◽  
Optical Depth ◽  
Dust Storm ◽  
Curiosity Rover

scholarly journals Dust Particle Size Distributions during Spring in Yinchuan, China

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jiangfeng Shao ◽  
Jiandong Mao
Keyword(s):  
Particle Size ◽  
Wind Speed ◽  
Dust Particle ◽  
Dust Storm ◽  
Fine Particles ◽  
Dust Particles ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Mass Distributions ◽  
Mass Size

Dust particle size distributions in Yinchuan, China, were measured during March and April 2014, using APS-3321 sampler. The distributions were measured under different dust conditions (background, floating dust, blowing dust, and dust storm) and statistical analyses were performed. The results showed that, under different dust conditions, the instantaneous number concentrations of dust particles differed widely. For example, during blowing sand and dust storm conditions, instantaneous dust particles concentrations varied substantially, while, under floating dust conditions, concentration differences were relatively small. The average dust particles size distributions were unimodal under all dust conditions, but the average surface area and mass size distributions were all bimodal. These distributions had peaks in different locations under different dust conditions. Under different dust conditions, wind speed and humidity were very important factors for particles size distributions. With increasing wind speed and decreasing humidity, fine particles were dominant in the atmosphere and the number and mass distributions of the coarse particles were indicative of long-range transport from surrounding deserts. Different dust conditions had different influences on PM1, PM2.5, and PM10concentrations.

scholarly journals Dust particle size and optical depth on Mars retrieved by the MSL navigation cameras

Icarus ◽  
2019 ◽  
Vol 319 ◽  
pp. 43-57 ◽  
Author(s):  
H. Chen-Chen ◽  
S. Pérez-Hoyos ◽  
A. Sánchez-Lavega
Keyword(s):  
Particle Size ◽  
Dust Particle ◽  
Optical Depth

scholarly journals Observations of Saharan dust microphysical and optical properties from the Eastern Atlantic during NAMMA airborne field campaign

2011 ◽  
Vol 11 (2) ◽  
pp. 723-740 ◽  
Author(s):  
G. Chen ◽  
L. D. Ziemba ◽  
D. A. Chu ◽  
K. L. Thornhill ◽  
G. L. Schuster ◽  
...  
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Dust Particle ◽  
Saharan Dust ◽  
Dust Particles ◽  
Small Range ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Field Campaign ◽  
Sahara Dust

Abstract. As part of the international project entitled "African Monsoon Multidisciplinary Analysis (AMMA)", NAMMA (NASA AMMA) aimed to gain a better understanding of the relationship between the African Easterly Waves (AEWs), the Sahara Air Layer (SAL), and tropical cyclogenesis. The NAMMA airborne field campaign was based out of the Cape Verde Islands during the peak of the hurricane season, i.e., August and September 2006. Multiple Sahara dust layers were sampled during 62 encounters in the eastern portion of the hurricane main development region, covering both the eastern North Atlantic Ocean and the western Saharan desert (i.e., 5–22° N and 10–35° W). The centers of these layers were located at altitudes between 1.5 and 3.3 km and the layer thickness ranged from 0.5 to 3 km. Detailed dust microphysical and optical properties were characterized using a suite of in-situ instruments aboard the NASA DC-8 that included a particle counter, an Ultra-High Sensitivity Aerosol Spectrometer, an Aerodynamic Particle Sizer, a nephelometer, and a Particle Soot Absorption Photometer. The NAAMA sampling inlet has a size cut (i.e., 50% transmission efficiency size) of approximately 4 μm in diameter for dust particles, which limits the representativeness of the NAMMA observational findings. The NAMMA dust observations showed relatively low particle number densities, ranging from 268 to 461 cm−3, but highly elevated volume density with an average at 45 μm3 cm−3. NAMMA dust particle size distributions can be well represented by tri-modal lognormal regressions. The estimated volume median diameter (VMD) is averaged at 2.1 μm with a small range of variation regardless of the vertical and geographical sampling locations. The Ångström Exponent assessments exhibited strong wavelength dependence for absorption but a weak one for scattering. The single scattering albedo was estimated at 0.97 ± 0.02. The imaginary part of the refractive index for Sahara dust was estimated at 0.0022, with a range from 0.0015 to 0.0044. Closure analysis showed that observed scattering coefficients are highly correlated with those calculated from spherical Mie-Theory and observed dust particle size distributions. These values are generally consistent with literature values reported from studies with similar particle sampling size range.

scholarly journals EXPERIMENTAL STUDY OF THE EFFECTS OF COAL DUST PARTICLE SIZE ON LAMINAR BURNING VELOCITY IN A MIXTURE OF COAL DUST AND METHAN

2019 ◽  
Vol 34 (4) ◽  
pp. 47-55
Author(s):  
Hadis Moradi ◽  
◽  
Farhang Sereshki ◽  
Mohammad Ataei ◽  
Mohsen Nazari ◽  
...  
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Dust Particle ◽  
Coal Dust ◽  
Burning Velocity ◽  
Laminar Burning Velocity

scholarly journals Thermal infrared remote sensing of mineral dust over land and ocean: a spectral SVD based retrieval approach for IASI

2011 ◽  
Vol 4 (5) ◽  
pp. 757-773 ◽  
Author(s):  
L. Klüser ◽  
D. Martynenko ◽  
T. Holzer-Popp
Keyword(s):  
Particle Size ◽  
Dust Particle ◽  
Mineral Dust ◽  
A Priori ◽  
Thermal Infrared ◽  
Effective Radius ◽  
Northern Africa ◽  
Lookup Table ◽  
Dust Extinction ◽  
Dust Events

Abstract. From the high spectral resolution thermal infrared observations of the Infrared Atmospheric Sounding Interferometer (IASI) mineral dust AOD (transferred from thermal infrared to 0.5 μm) is retrieved using a Singular Vector Decomposition of brightness temperature spectra. As infrared retrieval based on 8–12 μm observations, dust observation with IASI is independent from solar illumination. Through the linear combinations of suitable independent singular vectors weighted by their contribution to the observed signal, and a projection of different a-priori dust spectra on the resulting signal the dust can be well distinguished from the influence of surface emissivity and gas absorption. In contrast to lookup-table based single-channel retrievals this method takes advantage of the spectral shape of dust extinction and surface and atmosphere influence over the total 8–12 μm window band. Using different a-priori spectra for dust extinction allows also for an estimation of dust particle size in terms of effective radius based on the respective dust model size distributions. These dust models are also used for the transfer of infrared AOD to 0.5 μm. Four months of IASI observations covering Northern Africa and Arabia are used for evaluation. Two large scale dust events, one covering the Arabian Peninsula and adjacent parts of the Indian Ocean, the other over the Atlantic Ocean off the coast of West-Africa, are analysed and compared with other satellite images. They also show the good suitability of IASI data for dust observation at day and night. Monthly means derived from IASI observations represent well the known seasonal cycles of dust activity over Northern Africa and Arabia. IASI Dust AOD0.5 μm and AERONET coarse mode AOD0.5 μm are reasonably well (linearly) correlated with ρ=0.623. Moreover, comparison of time series of AERONET and IASI observations shows that the evolution of dust events is very well covered by the IASI observations. Rank correlation between dust effective radius and AERONET Ångström exponent is −0.557 indicating the general capability of (qualitative) dust particle size information being provided by this method.

scholarly journals Effect of dust particle size on the plasma characteristics in a radio frequency capacitively coupled silane plasma

2018 ◽  
Vol 52 (1) ◽  
pp. 015206 ◽  
Author(s):  
Wen-Zhu Jia ◽  
Quan-Zhi Zhang ◽  
Xi-Feng Wang ◽  
Yuan-Hong Song ◽  
Ying-Ying Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Radio Frequency ◽  
Dust Particle ◽  
Capacitively Coupled ◽  
Plasma Characteristics ◽  
Silane Plasma

scholarly journals Study of dust particle size distribution in the air of work areas at cement production facilities

2019 ◽  
Vol 138 ◽  
pp. 01027
Author(s):  
Nadezhda Menzelintseva ◽  
Natalia Karapuzova ◽  
Awadh M. Redhwan ◽  
Ekaterina Fomina
Keyword(s):  
Mathematical Model ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Dust Particle ◽  
Shop Floor ◽  
Cement Plant ◽  
Regression Equations ◽  
Cement Production ◽  
Work Area

The particle size distribution of dust in the air of the work area has been determined for some cement plant shops. An experimental study has been conducted to explore the effects of microclimate parameters on the dust particle size distribution on the shop floor in the cement milling shop and cement packing shop, and regression equations have been obtained. A mathematical model has been developed to forecast the dust particle size distribution in the air of work areas of cement plants.

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