Titre du document / Document title

An analysis of rapid increases in condensation nuclei concentrations at a remote coastal site in western Ireland

Auteur(s) / Author(s)

GRENFELL J. L. ⁽¹⁾ ; HARRISON R. M. ⁽¹⁾ ; ALLEN A. G. ⁽¹⁾ ; SHI J. P. ⁽¹⁾ ; PENKETT S. A. ⁽²⁾ ; O'DOWD C. D. ⁽³⁾ ; SMITH M. H. ⁽³⁾ ; HILL M. K. ⁽³⁾ ; ROBERTSON L. ⁽⁴⁾ ; HEWITT C. N. ⁽⁴⁾ ; DAVISON B. ⁽⁴⁾ ; LEWIS A. C. ⁽⁵⁾ ; CREASEY D. J. ⁽⁶⁾ ; HEARD D. E. ⁽⁶⁾ ; HEBESTREIT K. ⁽⁷⁾ ; ALICKE B. ⁽⁷⁾ ; JAMES J. ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Institute of Public and Environmental Hcalth, University of Birmingham, Birmingham, ROYAUME-UNI
⁽²⁾ School of Environmcntal Scicnccs, Univcrsity of East Anglia, Norwich, ROYAUME-UNI
⁽³⁾ Centre for Marine & Atmosphcrie Sciences, School of the Environment, University of Sunderland, Sunderland, ROYAUME-UNI
⁽⁴⁾ Institute of Environmental and Natural Sciences, University of Lancaster, Lancaster, ROYAUME-UNI
⁽⁵⁾ The Environment Centre, University of Leeds, Leeds, ROYAUME-UNI
⁽⁶⁾ School of Chemistry, University of Leeds, Leeds, ROYAUME-UNI
⁽⁷⁾ Institut fuer Umweltphysik, University of Heidelberg, Heidelberg, ALLEMAGNE

Résumé / Abstract

Massive bursts in condensation nuclei (CN) concentration were recorded at a remote site on the west Irish coast during campaigns in summer 1996 and spring/summer 1997. Number concentrations of 3-7 nm diameter CN were observed to rise daily from 10²-10³ up to ∼10⁵ /cm³ for 1-3 hours. Data were collected as part of the Atmospheric Chemistry Studies in the Oceanic Environment program. In a previous paper the burst phenomenon was linked to the movement of the tide, and it was suggested that enhanced biogenic emissions occurred near low tide with concomitant rapid homogeneous gas phase CN formation. In this paper possible chemical mechanisms for the burst phenomenon are investigated. Two approaches are adopted. First, by assuming a 20:80 sulfate:water molar composition and calculating the number distribution using data from condensation particle counters, the total mass of CN formed during a burst is evaluated. This is compared with that mass of sulfate produced by OH-initiated dimethyl sulfide (DMS) oxidation. The procedure is termed mass balance. Second, a variety of chemical species are coplotted with tidal height. DMS oxidation is not believed to play a major role in CN formation at this site because (1) the mass balance calculations imply ambient DMS concentrations higher than those observed, and (2) gas phase HCI, HNO₃. SO₂, and NH₃ did not exhibit any discernible correlation with tidal height. Further, none of the suite of observed nonmethane hydrocarbons or DMS showed a tidal relation. No mechanism has to date been convincingly identified for the burst phenomenon.

Revue / Journal Title

Journal of geophysical research   ISSN 0148-0227 

Source / Source

1999, vol. 104, n^oD11, pp. 13771-13780 (1 p.1/4)

Langue / Language

Anglais

Editeur / Publisher

American Geophysical Union, Washington, DC, ETATS-UNIS  (1949) (Revue)

Mots-clés anglais / English Keywords

Atmospheric boundary layer ; Marine atmosphere ; Aerosols ; Condensation nucleus ; Concentration ; Coastal zone ; Biogenic factor ; Chemical reaction ; Sulfates ; Ireland ; Dimethyl sulfide ; Hydroxyl radicals ; Europe ;

Mots-clés français / French Keywords

Couche limite atmosphérique ; Atmosphère marine ; Aérosol ; Noyau condensation ; Concentration ; Zone côtière ; Facteur biogène ; Réaction chimique ; Sulfate ; Irlande ; Méthyle sulfure ; Radical hydroxyle ; Europe ;

Mots-clés espagnols / Spanish Keywords

Capa límite atmosférico ; Atmósfera marina ; Aerosol ; Núcleo condensación ; Concentración ; Zona costera ; Factor biógeno ; Reacción química ; Sulfato ; Irlanda ; Europa ;

Localisation / Location

INIST-CNRS, Cote INIST : 3144, 35400008552151.0050