气候变化领域集成服务门户(CCPortal): Inferring iron-oxide species content in atmospheric mineral dust from DSCOVR EPIC observations

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DOI	10.5194/acp-22-1395-2022
	Inferring iron-oxide species content in atmospheric mineral dust from DSCOVR EPIC observations
	Go, Sujung; Lyapustin, Alexei; Schuster, Gregory L.; Choi, Myungje; Ginoux, Paul; Chin, Mian; Kalashnikova, Olga; Dubovik, Oleg; Kim, Jhoon; da Silva, Arlindo; Holben, Brent; Reid, Jeffrey S.
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	1395
结束页码	1423
卷号	22 期号:2 页码:29
英文摘要	The iron-oxide content of dust in the atmosphere and most notably its apportionment between hematite (alpha-Fe2O3) and goethite (alpha-FeOOH) are key determinants in quantifying dust's light absorption, its top of atmosphere ultraviolet (UV) radiances used for dust monitoring, and ultimately shortwave dust direct radiative effects (DREs). Hematite and goethite column mass concentrations and iron-oxide mass fractions of total dust mass concentration were retrieved from the Deep Space Climate Observatory (DSCOVR) Earth Polychromatic Imaging Camera (EPIC) measurements in the ultraviolet-visible (UV-Vis) channels. The retrievals were performed for dust-identified aerosol plumes over land using aerosol optical depth (AOD) and the spectral imaginary refractive index provided by the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm over six continental regions (North America, North Africa, West Asia, Central Asia, East Asia, and Australia). The dust particles are represented as an internal mixture of non-absorbing host and absorbing hematite and goethite. We use the Maxwell Garnett effective medium approximation with carefully selected complex refractive indices of hematite and goethite that produce mass fractions of iron-oxide species consistent with in situ values found in the literature to derive the hematite and goethite volumetric/mass concentrations from MAIAC EPIC products. We compared the retrieved hematite and goethite concentrations with in situ dust aerosol mineralogical content measurements, as well as with published data. Our data display variations within the published range of hematite, goethite, and iron-oxide mass fractions for pure-mineral-dust cases. A specific analysis is presented for 15 sites over the main dust-source regions. Sites in the central Sahara, Sahel, and Middle East exhibit a greater temporal variability of iron oxides relative to other sites. The Niger site (13.52 degrees N, 2.63 degrees E) is dominated by goethite over the Harmattan season with a median of similar to 2 weight percentage (wt %) of iron oxide. The Saudi Arabia site (27.49 degrees N, 41.98 degrees E) over the Middle East also exhibited a surge of goethite content with the beginning of the shamal season. The Sahel dust is richer in iron oxide than Saharan and northern China dust except in summer. The Bodele Depression area shows a distinctively lower iron-oxide concentration (similar to 1 wt %) throughout the year. Finally, we show that EPIC data allow the constraining of the hematite refractive index. Specifically, we select 5 out of 13 different hematite refractive indices that are widely variable in published laboratory studies by constraining the iron-oxide mass ratio to the known measured values. The provided climatology of hematite and goethite mass fractions across the main dust regions of Earth will be useful for dust shortwave DRE studies and climate modeling.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000751070000001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273791
作者单位	University System of Maryland; University of Maryland Baltimore County; National Aeronautics & Space Administration (NASA); NASA Goddard Space Flight Center; National Aeronautics & Space Administration (NASA); NASA Langley Research Center; National Oceanic Atmospheric Admin (NOAA) - USA; California Institute of Technology; National Aeronautics & Space Administration (NASA); NASA Jet Propulsion Laboratory (JPL); Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Earth Sciences & Astronomy (INSU); Universite de Lille - ISITE; Universite de Lille; Yonsei University
推荐引用方式 GB/T 7714	Go, Sujung,Lyapustin, Alexei,Schuster, Gregory L.,et al. Inferring iron-oxide species content in atmospheric mineral dust from DSCOVR EPIC observations[J],2022,22(2):29.
APA	Go, Sujung.,Lyapustin, Alexei.,Schuster, Gregory L..,Choi, Myungje.,Ginoux, Paul.,...&Reid, Jeffrey S..(2022).Inferring iron-oxide species content in atmospheric mineral dust from DSCOVR EPIC observations.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(2),29.
MLA	Go, Sujung,et al."Inferring iron-oxide species content in atmospheric mineral dust from DSCOVR EPIC observations".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.2(2022):29.