Arid
DOI10.5194/acp-12-287-2012
Immersion mode heterogeneous ice nucleation by an illite rich powder representative of atmospheric mineral dust
Broadley, S. L.; Murray, B. J.; Herbert, R. J.; Atkinson, J. D.; Dobbie, S.; Malkin, T. L.; Condliffe, E.; Neve, L.
通讯作者Murray, B. J.
来源期刊ATMOSPHERIC CHEMISTRY AND PHYSICS
ISSN1680-7316
EISSN1680-7324
出版年2012
卷号12期号:1页码:287-307
英文摘要

Atmospheric dust rich in illite is transported globally from arid regions and impacts cloud properties through the nucleation of ice. We present measurements of ice nucleation in water droplets containing known quantities of an illite rich powder under atmospherically relevant conditions. The illite rich powder used here, NX illite, has a similar mineralogical composition to atmospheric mineral dust sampled in remote locations, i.e. dust which has been subject to long range transport, cloud processing and sedimentation. Arizona Test Dust, which is used in other ice nucleation studies as a model atmospheric dust, has a significantly different mineralogical composition and we suggest that NX illite is a better surrogate of natural atmospheric dust.


Using optical microscopy, heterogeneous nucleation in the immersion mode by NX illite was observed to occur dominantly between 246K and the homogeneous freezing limit. In general, higher freezing temperatures were observed when larger surface areas of NX illite were present within the drops. Homogenous nucleation was observed to occur in droplets containing low surface areas of NX illite. We show that NX illite exhibits strong particle to particle variability in terms of ice nucleating ability, with similar to 1 in 10(5) particles dominating ice nucleation when high surface areas were present. In fact, this work suggests that the bulk of atmospheric mineral dust particles may be less efficient at nucleating ice than assumed in current model parameterisations.


For droplets containing <= 2x10(-6) cm(2) of NX illite, freezing temperatures did not noticeably change when the cooling rate was varied by an order of magnitude. The data obtained during cooling experiments (surface area <= 2x10(-6) cm(2)) is shown to be inconsistent with the single component stochastic model, but is well described by the singular model (n(s)(236.2K <= T <= 247.5 K) = exp(6.53043x10(4)-8.2153088x10(2)T + 3.446885376T(2) - 4.822268x10(-3)T(3)). However, droplets continued to freeze when the temperature was held constant, which is inconsistent with the time independent singular model. We show that this apparent discrepancy can be resolved using a multiple component stochastic model in which it is assumed that there are many types of nucleation sites, each with a unique temperature dependent nucleation coefficient. Cooling rate independence can be achieved with this time dependent model if the nucleation rate coefficients increase very rapidly with decreasing temperature, thus reconciling our measurement of nucleation at constant temperature with the cooling rate independence.


类型Article
语种英语
国家England
收录类别SCI-E
WOS记录号WOS:000300320200015
WOS关键词WATER DROPLETS ; BIOLOGICAL PARTICLES ; NUCLEI ; AEROSOLS ; SOOT ; CRYSTALLIZATION ; KAOLINITE ; ATLANTIC ; CLAY
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/2XILL650/171407
作者单位Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W Yorkshire, England
推荐引用方式
GB/T 7714
Broadley, S. L.,Murray, B. J.,Herbert, R. J.,et al. Immersion mode heterogeneous ice nucleation by an illite rich powder representative of atmospheric mineral dust[J],2012,12(1):287-307.
APA Broadley, S. L..,Murray, B. J..,Herbert, R. J..,Atkinson, J. D..,Dobbie, S..,...&Neve, L..(2012).Immersion mode heterogeneous ice nucleation by an illite rich powder representative of atmospheric mineral dust.ATMOSPHERIC CHEMISTRY AND PHYSICS,12(1),287-307.
MLA Broadley, S. L.,et al."Immersion mode heterogeneous ice nucleation by an illite rich powder representative of atmospheric mineral dust".ATMOSPHERIC CHEMISTRY AND PHYSICS 12.1(2012):287-307.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[Broadley, S. L.]的文章
[Murray, B. J.]的文章
[Herbert, R. J.]的文章
百度学术
百度学术中相似的文章
[Broadley, S. L.]的文章
[Murray, B. J.]的文章
[Herbert, R. J.]的文章
必应学术
必应学术中相似的文章
[Broadley, S. L.]的文章
[Murray, B. J.]的文章
[Herbert, R. J.]的文章
相关权益政策
暂无数据
收藏/分享

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。