نتایج جستجو برای: mineral dust

تعداد نتایج: 106800  

2008
A. A. Chudnovsky E. Ben-Dor

The influence of mineral and anthropogenic dust components on the VIS-NIR-SWIR spectral reflectance of artificial laboratory dust mixtures was evaluated and used in combination with Partial Least Squares (PLS) regression to construct a model that correlates the dust content with its reflectance. Small amounts of dust (0.018–0.33 mg/cm2) were collected using glass traps placed in different indoo...

2013
S. M. Aarons

Isotopic characterization of aerosol mineral particles (atmospheric dust) of varying sizes is essential in classifying source areas, and for determining the source of dust deposited over oceans and icesheets. However, the effect of atmospheric transport on radiogenic isotopic compositions is not well constrained, making provenance interpretation difficult. In order to investigate the isotopic v...

2010
Matthew S. Johnson Nicholas Meskhidze Fabien Solmon Santiago Gassó Patrick Y. Chuang Diego M. Gaiero Robert M. Yantosca Shiliang Wu Yuxuan Wang Claire Carouge

[1] The global chemical transport model GEOS‐Chem, implemented with a dust‐iron dissolution scheme, was used to analyze the magnitude and spatial distribution of mineral dust and soluble‐iron (sol‐Fe) deposition to the South Atlantic Ocean (SAO). The comparison of model results with remotely sensed data shows that GEOS‐Chem can capture dust source regions in Patagonia and characterize the tempo...

ژورنال: ژئوفیزیک ایران 2020
Abbasali Dadashi-Roudbari Alireza Shakiba Mahmoud Ahmadi,

The research results indicated that wet and dry dust deposition is a function of geographical characteristics. The seasonal wet and dry dust deposition and Fine Particles (PM 2.5) correlation in Iran with elevation, latitude and longitude results that the maximum correlation belongs to height, followed by latitude and longitude; meanwhile height and latitude are strongly and reversely correlate...

2007
A. Tabazadeh M. Z. Jacobson H. B. Singh J. S. Lin R. B. Chatfield

The abundance of gas phase nitric acid in the upper troposphere is overestimated by global chemistry-transport models, especially during the spring and summer seasons. Recent aircraft data obtained over the central US show that mineral aerosols were abundant in the upper troposphere during spring. Chemical reactions on mineral dust may provide an important sink for nitric acid. In regions where...

2016
Luke Bridgestock Tina van de Flierdt Mark Rehkämper Maxence Paul Rob Middag Angela Milne Maeve C Lohan Alex R Baker Rosie Chance Roulin Khondoker Stanislav Strekopytov Emma Humphreys-Williams Eric P Achterberg Micha J A Rijkenberg Loes J A Gerringa Hein J W de Baar

Anthropogenic emissions completely overwhelmed natural marine lead (Pb) sources during the past century, predominantly due to leaded petrol usage. Here, based on Pb isotope measurements, we reassess the importance of natural and anthropogenic Pb sources to the tropical North Atlantic following the nearly complete global cessation of leaded petrol use. Significant proportions of up to 30-50% of ...

2016
S. Merikallio H. Lindqvist T. Nousiainen M. Kahnert

We study the applicability of spheroidal model particles for simulating the single-scattering optical properties of mineral dust aerosols. To assess the range of validity of this model, calculations are compared to laboratory observations for five different dust samples at two wavelengths. We further investigate whether the best-fit shape distributions of spheroids for different mineral dust sa...

2010
C. Zhao Xiaohong Liu L. R. Leung S. A. McFarlane X. Liu B. Johnson

A fully coupled meteorology-chemistry-aerosol model (WRF-Chem) is applied to simulate mineral dust and its shortwave (SW) radiative forcing over North Africa. Two dust emission schemes (GOCART and DUSTRAN) and two aerosol models (MADE/SORGAM and MOSAIC) are adopted in simulations to investigate the modeling sensitivities to dust emissions and aerosol size treatments. The modeled size distributi...

2014
K. Osada S. Ura M. Kagawa M. Mikami T. Y. Tanaka S. Matoba K. Aoki M. Shinoda Y. Kurosaki M. Hayashi A. Shimizu

Recent ground networks and satellite remotesensing observations have provided useful data related to spatial and vertical distributions of mineral dust particles in the atmosphere. However, measurements of temporal variations and spatial distributions of mineral dust deposition fluxes are limited in terms of their duration, location, and processes of deposition. To ascertain temporal variations...

Journal: :Journal of environmental sciences 2016
Li Zhou Weigang Wang Maofa Ge Shengrui Tong

The heterogeneous uptake processes of hydrogen peroxide on Arizona test dust and two types of authentic Chinese mineral dusts, i.e., Inner Mongolia desert dust and Xinjiang calciferous dust, were investigated using a Knudsen cell reactor coupled with a quadrupole mass spectrometer. The uptake coefficients were measured as a function of the initial concentration of H2O2 from 2.6 × 10(11) to 1.2 ...

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