气候变化领域集成服务门户(CCPortal): The importance of acid-processed meteoric smoke relative to meteoricfragments for crystal nucleation in polar stratospheric clouds

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DOI	10.5194/acp-23-2215-2023
	The importance of acid-processed meteoric smoke relative to meteoricfragments for crystal nucleation in polar stratospheric clouds
	James, Alexander D.; Pace, Finn; Sikora, Sebastien N. F.; Mann, Graham W.; Plane, John M. C.; Murray, Benjamin J.
发表日期	2023
ISSN	1680-7316
EISSN	1680-7324
起始页码	2215
结束页码	2233
卷号	23 期号:3 页码:19
英文摘要	The crystal formation of nitric acid trihydrate (NAT) in the absence of water ice is important for a subset of polar stratospheric clouds (PSCs) and thereby ozone depletion. It has been suggested that either fragmented meteoroids or meteoric smoke particles (MSPs), or possibly both, are important as heterogeneous nuclei of these crystals. Previous work has focused on the nucleating ability of meteoric material in nitric acid in the absence of sulfuric acid. However, it is known that when immersed in stratospheric sulfuric acid droplets, metal-containing meteoric material particles partially dissolve and components can reprecipitate as silica and alumina that have different morphologies to the original meteoric material. Hence, in this study, we experimentally and theoretically explore the relative role that sulfuric acid-processed MSPs and meteoric fragments may play in NAT nucleation in PSCs.We compared meteoric fragments that had recently been prepared (by milling a meteorite sample) to a sample annealed under conditions designed to simulate heating during entry into the Earth's atmosphere. Whilst the addition of sulfuric acid decreased the nucleating ability of the recently milled meteoric material relative to nucleation in binary nitric acid-water solutions (at similar NAT saturation ratio), the annealed meteoric fragments nucleated NAT with a similar effectiveness in both solutions. However, combining our results with measured fluxes of meteoric material to the Earth, sedimentation modelling and recent experiments on fragmentation of incoming meteoroids suggests that it is unlikely for there to be sufficient fragments to contribute to the nucleation of crystalline NAT particles.We then considered silica formed from sulfuric acid-processed MSPs. Our previous work showed that nanoparticulate silica (radius similar to 6 nm) is a relatively poor promoter of nucleation compared with micron-scaled silica particles, which were more effective. Both materials have similar chemical and structural (crystallographically amorphous) properties, indicating that size is critical. Here, we account for surface curvature of primary grains using the Classical Nucleation Theory (CNT) to explore this size dependence. This model is able to explain the discrepancy in nucleation effectiveness of fumed silica and fused quartz by treating their nucleating activity (contact angle) as equal but with differing particle size (or surface curvature), assuming interfacial energies that are physically reasonable. Here, we use this CNT model to present evidence that nucleation of NAT on acid-processed MSPs, where the primary grain size is tens of nanometres, is also effective enough to contribute to NAT crystals in early season PSCs where there is an absence of ice.This study demonstrates that the modelling of crystal nucleation in PSCs and resulting ozone depletion relies on an accurate understanding of the transport and chemical processing of MSPs. This will affect estimated sensitivity of stratospheric chemistry to rare events such as large volcanic eruptions and long-term forecasting of ozone recovery in a changing climate.
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:000933298800001
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/272975
作者单位	University of Leeds; University of Leeds
推荐引用方式 GB/T 7714	James, Alexander D.,Pace, Finn,Sikora, Sebastien N. F.,et al. The importance of acid-processed meteoric smoke relative to meteoricfragments for crystal nucleation in polar stratospheric clouds[J],2023,23(3):19.
APA	James, Alexander D.,Pace, Finn,Sikora, Sebastien N. F.,Mann, Graham W.,Plane, John M. C.,&Murray, Benjamin J..(2023).The importance of acid-processed meteoric smoke relative to meteoricfragments for crystal nucleation in polar stratospheric clouds.ATMOSPHERIC CHEMISTRY AND PHYSICS,23(3),19.
MLA	James, Alexander D.,et al."The importance of acid-processed meteoric smoke relative to meteoricfragments for crystal nucleation in polar stratospheric clouds".ATMOSPHERIC CHEMISTRY AND PHYSICS 23.3(2023):19.