Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory
This study investigates the processes and conditions favouring the formation of nanoparticles (diameter<10 nm) which are frequently observed on high mountains reaching the low free troposphere. This was done through an analysis of a data set collected at Izaña Global Atmospheric Watch Observatory...
Published in: | Atmospheric Chemistry and Physics |
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Format: | Article in Journal/Newspaper |
Language: | English |
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European Geosciences Union
2009
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Online Access: | http://hdl.handle.net/10272/7925 https://doi.org/10.5194/acp-9-6319-2009 |
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ftunivhuelva:oai:rabida.uhu.es:10272/7925 2023-05-15T17:37:15+02:00 Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory Rodríguez González, Sergio González, Y. Cuevas, Emilio Ramos, R. Romero, P. M. Abreu Afonso, J. Redondas, A. 2009 http://hdl.handle.net/10272/7925 https://doi.org/10.5194/acp-9-6319-2009 eng eng European Geosciences Union Rodríguez González, S., González, Y., Cuevas, E., Ramos, R., Romero, P. M., Abreu Afonso, J., Redondas, A.: "Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory". Atmospheric Chemistry and Physics. Vol. 9, págs. 6319–6335 (2009). ISSN 1680-7316 1680-7316 1680-7324 http://hdl.handle.net/10272/7925 doi:10.5194/acp-9-6319-2009 Atribución-NoComercial-SinDerivadas 3.0 España http://creativecommons.org/licenses/by-nc-nd/3.0/es/ info:eu-repo/semantics/openAccess CC-BY-NC-ND Nanoparticles Troposphere Izaña Global Atmospheric Watch Observatory Ozone Trophosfere North Atlantic Ozono Troposfera Atlántico Norte info:eu-repo/semantics/article 2009 ftunivhuelva https://doi.org/10.5194/acp-9-6319-2009 2021-08-11T19:42:29Z This study investigates the processes and conditions favouring the formation of nanoparticles (diameter<10 nm) which are frequently observed on high mountains reaching the low free troposphere. This was done through an analysis of a data set collected at Izaña Global Atmospheric Watch Observatory (Canary Islands; 2367mabove sea level). This high mountain supersite is located well above the stratocumulus layer characteristic of the subtropical oceanic tropospheres. At night, when the catabic flow regime is well established, free troposphere aerosols were measured. The development of orographic buoyant upward flows during daylight resulted in an increase of water vapour, SO2 and NOy concentrations. These ascending airflows perturbed the free troposphere and resulted in high concentrations of 3–10 nm particles (N3−10) due to new particle formation. An analysis of the 5-min average time series allowed the identification of two main types of N3−10 event. In Type I events a linear relationship between N3−10 and SO2 was observed (r2 coefficients 0.70–0.95 and a mean slope of 11 cm−3 ppt−1 for 5-min averaged data; SO2 concentrations from tens to hundreds of ppt). These particles seem to be formed during upward transport (probably within or after the outflows of clouds typically located below Iza˜na). During Type II events, no correlation between SO2 and N3−10 was observed and 3–10 nm particles were formed in-situ at noon and during the afternoon due to the condensation of vapours linked to photochemistry. New particle formation was observed almost every day owing to the favourable conditions associated with the entry of boundary layer air in the low free troposphere, even if SO2 concentrations are rather low at Iza˜na (tens to hundreds of ppt). The low surface area of pre-existing particles, low temperature and high radiation intensity clearly favoured the formation of nanoparticles. The low surface area of pre-existing particles in the upward flows is furthered by in-cloud particles scavenging in the stratocumulus layer typically located below Iza˜na. The higher temperature and the presence of coarse Saharan dust particles decrease the efficiency of the new particle formation mechanisms in summer. Thus, the “N3−10 versus SO2” slope (for r2>0.7 cases) was higher in autumn and winter ( 15 cm−3 ppt−1 as average) than in summer (2–8 cm−3 ppt−1). These field observations suggest that elevated mounts that reaches the free troposphere may act as source regions for new particles. Article in Journal/Newspaper North Atlantic Universidad de Huelva: Arias Montano Atmospheric Chemistry and Physics 9 17 6319 6335 |
institution |
Open Polar |
collection |
Universidad de Huelva: Arias Montano |
op_collection_id |
ftunivhuelva |
language |
English |
topic |
Nanoparticles Troposphere Izaña Global Atmospheric Watch Observatory Ozone Trophosfere North Atlantic Ozono Troposfera Atlántico Norte |
spellingShingle |
Nanoparticles Troposphere Izaña Global Atmospheric Watch Observatory Ozone Trophosfere North Atlantic Ozono Troposfera Atlántico Norte Rodríguez González, Sergio González, Y. Cuevas, Emilio Ramos, R. Romero, P. M. Abreu Afonso, J. Redondas, A. Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory |
topic_facet |
Nanoparticles Troposphere Izaña Global Atmospheric Watch Observatory Ozone Trophosfere North Atlantic Ozono Troposfera Atlántico Norte |
description |
This study investigates the processes and conditions favouring the formation of nanoparticles (diameter<10 nm) which are frequently observed on high mountains reaching the low free troposphere. This was done through an analysis of a data set collected at Izaña Global Atmospheric Watch Observatory (Canary Islands; 2367mabove sea level). This high mountain supersite is located well above the stratocumulus layer characteristic of the subtropical oceanic tropospheres. At night, when the catabic flow regime is well established, free troposphere aerosols were measured. The development of orographic buoyant upward flows during daylight resulted in an increase of water vapour, SO2 and NOy concentrations. These ascending airflows perturbed the free troposphere and resulted in high concentrations of 3–10 nm particles (N3−10) due to new particle formation. An analysis of the 5-min average time series allowed the identification of two main types of N3−10 event. In Type I events a linear relationship between N3−10 and SO2 was observed (r2 coefficients 0.70–0.95 and a mean slope of 11 cm−3 ppt−1 for 5-min averaged data; SO2 concentrations from tens to hundreds of ppt). These particles seem to be formed during upward transport (probably within or after the outflows of clouds typically located below Iza˜na). During Type II events, no correlation between SO2 and N3−10 was observed and 3–10 nm particles were formed in-situ at noon and during the afternoon due to the condensation of vapours linked to photochemistry. New particle formation was observed almost every day owing to the favourable conditions associated with the entry of boundary layer air in the low free troposphere, even if SO2 concentrations are rather low at Iza˜na (tens to hundreds of ppt). The low surface area of pre-existing particles, low temperature and high radiation intensity clearly favoured the formation of nanoparticles. The low surface area of pre-existing particles in the upward flows is furthered by in-cloud particles scavenging in the stratocumulus layer typically located below Iza˜na. The higher temperature and the presence of coarse Saharan dust particles decrease the efficiency of the new particle formation mechanisms in summer. Thus, the “N3−10 versus SO2” slope (for r2>0.7 cases) was higher in autumn and winter ( 15 cm−3 ppt−1 as average) than in summer (2–8 cm−3 ppt−1). These field observations suggest that elevated mounts that reaches the free troposphere may act as source regions for new particles. |
format |
Article in Journal/Newspaper |
author |
Rodríguez González, Sergio González, Y. Cuevas, Emilio Ramos, R. Romero, P. M. Abreu Afonso, J. Redondas, A. |
author_facet |
Rodríguez González, Sergio González, Y. Cuevas, Emilio Ramos, R. Romero, P. M. Abreu Afonso, J. Redondas, A. |
author_sort |
Rodríguez González, Sergio |
title |
Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory |
title_short |
Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory |
title_full |
Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory |
title_fullStr |
Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory |
title_full_unstemmed |
Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory |
title_sort |
atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at izaña mountain observatory |
publisher |
European Geosciences Union |
publishDate |
2009 |
url |
http://hdl.handle.net/10272/7925 https://doi.org/10.5194/acp-9-6319-2009 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Rodríguez González, S., González, Y., Cuevas, E., Ramos, R., Romero, P. M., Abreu Afonso, J., Redondas, A.: "Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory". Atmospheric Chemistry and Physics. Vol. 9, págs. 6319–6335 (2009). ISSN 1680-7316 1680-7316 1680-7324 http://hdl.handle.net/10272/7925 doi:10.5194/acp-9-6319-2009 |
op_rights |
Atribución-NoComercial-SinDerivadas 3.0 España http://creativecommons.org/licenses/by-nc-nd/3.0/es/ info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.5194/acp-9-6319-2009 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
9 |
container_issue |
17 |
container_start_page |
6319 |
op_container_end_page |
6335 |
_version_ |
1766137060247207936 |