Structure and water attachment rates of ice in the atmosphere: role of nitrogen

In this work we perform computer simulations of the ice surface in order to elucidate the role of nitrogen in the crystal growth rates and crystal habits of snow in the atmosphere. In pure water vapor at temperatures typical of ice crystal formation in cirrus clouds, we find that basal and primary p...

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Detalles Bibliográficos
Autores: Llombart, Pablo, Bergua, Ramón M., Noya, Eva G., MacDowell, Luis G.
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/12387
Acceso en línea:https://hdl.handle.net/20.500.14352/12387
Access Level:acceso abierto
Palabra clave:544
crystal growth
ice
surfaces
adsorption
attachment coefficients
snow
Física atmosférica
Química física (Física)
Superficies (Física)
Termodinámica
Cristalografía (Geología)
Agua
2501 Ciencias de la Atmósfera
2210 Química Física
2211.28 Superficies
2213 Termodinámica
2303.31 Química del Agua
id ES_e8d8656f105dd324dca7cf66b2b3b123
oai_identifier_str oai:docta.ucm.es:20.500.14352/12387
network_acronym_str ES
network_name_str España
repository_id_str
spelling Structure and water attachment rates of ice in the atmosphere: role of nitrogenLlombart, PabloBergua, Ramón M.Noya, Eva G.MacDowell, Luis G.544crystal growthicesurfacesadsorptionattachment coefficientssnowFísica atmosféricaQuímica física (Física)Superficies (Física)TermodinámicaCristalografía (Geología)Agua2501 Ciencias de la Atmósfera2210 Química Física2211.28 Superficies2213 Termodinámica2303.31 Química del AguaIn this work we perform computer simulations of the ice surface in order to elucidate the role of nitrogen in the crystal growth rates and crystal habits of snow in the atmosphere. In pure water vapor at temperatures typical of ice crystal formation in cirrus clouds, we find that basal and primary prismatic facets exhibit a layer of premelted ice, with thickness in the subnanometer range. For partial pressures of 1 bar, well above the expected values in the troposphere, we find that only small amounts of nitrogen are adsorbed. The adsorption takes place onto the premelted surface, and hardly any nitrogen dissolves within the premelting film. The premelting film thickness does not change either. We quantify the resulting change of the ice/vapor surface tension to be in the hundredth of mN m−1 and find that the structure of the pristine ice surface is not changed in a significant manner. We perform a trajectory analysis of colliding water molecules, and find that the attachment rates from direct ballistic collision are very close to unity irrespective of the nitrogen pressure. Nitrogen is however at sufficient density to deflect a fraction of trajectories with smaller distance than the mean free path. Our results show explicitly that the reported differences in growth rates measured in pure water vapor and a controlled nitrogen atmosphere are not related to a significant disruption of the ice surface due to nitrogen adsorption. On the contrary, we show clearly from our trajectory analysis that nitrogen slows down the crystal growth rates due to collisions between water molecules with bulk nitrogen gas. This clarifies the long standing controversy of the role of inert gases on crystal growth rates and demonstrates their influence is solely related to the diffusion limited flow of water vapor across the gas phase.Royal Society of ChemistryUniversidad Complutense de Madrid20192019-08-2120192019-08-21journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/12387reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/123872026-06-02T12:44:21Z
dc.title.none.fl_str_mv Structure and water attachment rates of ice in the atmosphere: role of nitrogen
title Structure and water attachment rates of ice in the atmosphere: role of nitrogen
spellingShingle Structure and water attachment rates of ice in the atmosphere: role of nitrogen
Llombart, Pablo
544
crystal growth
ice
surfaces
adsorption
attachment coefficients
snow
Física atmosférica
Química física (Física)
Superficies (Física)
Termodinámica
Cristalografía (Geología)
Agua
2501 Ciencias de la Atmósfera
2210 Química Física
2211.28 Superficies
2213 Termodinámica
2303.31 Química del Agua
title_short Structure and water attachment rates of ice in the atmosphere: role of nitrogen
title_full Structure and water attachment rates of ice in the atmosphere: role of nitrogen
title_fullStr Structure and water attachment rates of ice in the atmosphere: role of nitrogen
title_full_unstemmed Structure and water attachment rates of ice in the atmosphere: role of nitrogen
title_sort Structure and water attachment rates of ice in the atmosphere: role of nitrogen
dc.creator.none.fl_str_mv Llombart, Pablo
Bergua, Ramón M.
Noya, Eva G.
MacDowell, Luis G.
author Llombart, Pablo
author_facet Llombart, Pablo
Bergua, Ramón M.
Noya, Eva G.
MacDowell, Luis G.
author_role author
author2 Bergua, Ramón M.
Noya, Eva G.
MacDowell, Luis G.
author2_role author
author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 544
crystal growth
ice
surfaces
adsorption
attachment coefficients
snow
Física atmosférica
Química física (Física)
Superficies (Física)
Termodinámica
Cristalografía (Geología)
Agua
2501 Ciencias de la Atmósfera
2210 Química Física
2211.28 Superficies
2213 Termodinámica
2303.31 Química del Agua
topic 544
crystal growth
ice
surfaces
adsorption
attachment coefficients
snow
Física atmosférica
Química física (Física)
Superficies (Física)
Termodinámica
Cristalografía (Geología)
Agua
2501 Ciencias de la Atmósfera
2210 Química Física
2211.28 Superficies
2213 Termodinámica
2303.31 Química del Agua
description In this work we perform computer simulations of the ice surface in order to elucidate the role of nitrogen in the crystal growth rates and crystal habits of snow in the atmosphere. In pure water vapor at temperatures typical of ice crystal formation in cirrus clouds, we find that basal and primary prismatic facets exhibit a layer of premelted ice, with thickness in the subnanometer range. For partial pressures of 1 bar, well above the expected values in the troposphere, we find that only small amounts of nitrogen are adsorbed. The adsorption takes place onto the premelted surface, and hardly any nitrogen dissolves within the premelting film. The premelting film thickness does not change either. We quantify the resulting change of the ice/vapor surface tension to be in the hundredth of mN m−1 and find that the structure of the pristine ice surface is not changed in a significant manner. We perform a trajectory analysis of colliding water molecules, and find that the attachment rates from direct ballistic collision are very close to unity irrespective of the nitrogen pressure. Nitrogen is however at sufficient density to deflect a fraction of trajectories with smaller distance than the mean free path. Our results show explicitly that the reported differences in growth rates measured in pure water vapor and a controlled nitrogen atmosphere are not related to a significant disruption of the ice surface due to nitrogen adsorption. On the contrary, we show clearly from our trajectory analysis that nitrogen slows down the crystal growth rates due to collisions between water molecules with bulk nitrogen gas. This clarifies the long standing controversy of the role of inert gases on crystal growth rates and demonstrates their influence is solely related to the diffusion limited flow of water vapor across the gas phase.
publishDate 2019
dc.date.none.fl_str_mv 2019
2019-08-21
2019
2019-08-21
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/12387
url https://hdl.handle.net/20.500.14352/12387
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Royal Society of Chemistry
publisher.none.fl_str_mv Royal Society of Chemistry
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,300724