干旱区生态环境知识资源中心(Arid): Insights into the single-particle composition, size, mixing state, and aspect ratio of freshly emitted mineral dust from field measurements in the Moroccan Sahara using electron microscopy

Arid

DOI	10.5194/acp-23-3861-2023
	Insights into the single-particle composition, size, mixing state, and aspect ratio of freshly emitted mineral dust from field measurements in the Moroccan Sahara using electron microscopy
	Panta, Agnesh; Kandler, Konrad; Alastuey, Andres; Gonzalez-Florez, Cristina; Gonzalez-Romero, Adolfo; Klose, Martina; Querol, Xavier; Reche, Cristina; Yus-Diez, Jesus; Perez Garcia-Pando, Carlos
通讯作者	Panta, A
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
ISSN	1680-7316
EISSN	1680-7324
出版年	2023
卷号	23 期号:6 页码:3861-3885
英文摘要	The chemical and morphological properties of mineral dust aerosols emitted by wind erosion from arid and semi-arid regions influence climate, ocean, and land ecosystems; air quality; and multiple socio-economic sectors. However, there is an incomplete understanding of the emitted dust particle size distribution (PSD) in terms of its constituent minerals that typically result from the fragmentation of soil aggregates during wind erosion. The emitted dust PSD affects the duration of particle transport and thus each mineral's global distribution, along with its specific effect upon climate. This lack of understanding is largely due to the scarcity of relevant in situ measurements in dust sources. To advance our understanding of the physicochemical properties of the emitted dust PSD, we present insights into the elemental composition and morphology of individual dust particles collected during the FRontiers in dust minerAloGical coMposition and its Effects upoN climaTe (FRAGMENT) field campaign in the Moroccan Sahara in September 2019. We analyzed more than 300 000 freshly emitted individual particles by performing offline analysis in the laboratory using scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectrometry (EDX). Eight major particle-type classes were identified with clay minerals making up the majority of the analyzed particles both by number and mass, followed by quartz, whereas carbonates and feldspar contributed to a lesser extent. We provide an exhaustive analysis of the PSD and potential mixing state of different particle types, focusing largely on iron-rich (Fe oxide-hydroxides) and feldspar particles, which are key to the effects of dust upon radiation and clouds, respectively. Nearly pure or externally mixed Fe oxide-hydroxides are present mostly in diameters smaller than 2 mu m, with the highest fraction below 1 mu m at about 3.75 % abundance by mass. Fe oxide-hydroxides tend to be increasingly internally mixed with other minerals, especially clays, as particle size increases; i.e., the volume fraction of Fe oxide-hydroxides in aggregates decreases with particle size. Pure (externally mixed) feldspar represented 3.2 % of all the particles by mass, of which we estimated about a 10th to be K-feldspar. The externally mixed total feldspar and K-feldspar abundances are relatively invariant with particle size, in contrast to the increasing abundance of feldspar-like (internally mixed) aggregates with particle size with mass fractions ranging from 5 % to 18 %. We also found that overall the median aspect ratio is rather constant across particle size and mineral groups, although we obtain slightly higher aspect ratios for internally mixed particles. The detailed information on the composition of freshly emitted individual dust particles and quantitative analysis of their mixing state presented here can be used to constrain climate models including mineral species in their representation of the dust cycle.
类型	Article
语种	英语
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:000961065500001
WOS关键词	NORTH-AFRICAN DUST ; OPTICAL-PROPERTIES ; RELATIVE-HUMIDITY ; ICE NUCLEATION ; DESERT DUST ; RADIATIVE PROPERTIES ; CHEMICAL-PROPERTIES ; GLOBAL DISTRIBUTION ; SHORTWAVE SPECTRUM ; REFRACTIVE-INDEX
WOS类目	Environmental Sciences ; Meteorology & Atmospheric Sciences
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/395490
推荐引用方式 GB/T 7714	Panta, Agnesh,Kandler, Konrad,Alastuey, Andres,et al. Insights into the single-particle composition, size, mixing state, and aspect ratio of freshly emitted mineral dust from field measurements in the Moroccan Sahara using electron microscopy[J],2023,23(6):3861-3885.
APA	Panta, Agnesh.,Kandler, Konrad.,Alastuey, Andres.,Gonzalez-Florez, Cristina.,Gonzalez-Romero, Adolfo.,...&Perez Garcia-Pando, Carlos.(2023).Insights into the single-particle composition, size, mixing state, and aspect ratio of freshly emitted mineral dust from field measurements in the Moroccan Sahara using electron microscopy.ATMOSPHERIC CHEMISTRY AND PHYSICS,23(6),3861-3885.
MLA	Panta, Agnesh,et al."Insights into the single-particle composition, size, mixing state, and aspect ratio of freshly emitted mineral dust from field measurements in the Moroccan Sahara using electron microscopy".ATMOSPHERIC CHEMISTRY AND PHYSICS 23.6(2023):3861-3885.