Files and links (1)
Published, Version of Record (VoR)CC BY V4.0, Open
Journal article
South East Pacific atmospheric composition and variability sampled along 20 degrees S during VOCALS-REx
Atmospheric chemistry and physics, v 11(11), pp 5237-5262
01 Jan 2011
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
The VAMOS Ocean-Cloud-Atmosphere-Land Regional Experiment (VOCALS-REx) was conducted from 15 October to 15 November 2008 in the South East Pacific (SEP) region to investigate interactions between land, sea and atmosphere in this unique tropical eastern ocean environment and to improve the skill of global and regional models in representing the region. This study synthesises selected aircraft, ship and surface site observations from VOCALS-REx to statistically summarise and characterise the atmospheric composition and variability of the Marine Boundary Layer (MBL) and Free Troposphere (FT) along the 20 degrees S parallel between 70 degrees W and 85 degrees W. Significant zonal gradients in mean MBL sub-micron aerosol particle size and composition, carbon monoxide, sulphur dioxide and ozone were seen over the campaign, with a generally more variable and polluted coastal environment and a less variable, more pristine remote maritime regime. Gradients in aerosol and trace gas concentrations were observed to be associated with strong gradients in cloud droplet number. The FT was often more polluted in terms of trace gases than the MBL in the mean; however increased variability in the FT composition suggests an episodic nature to elevated concentrations. This is consistent with a complex vertical interleaving of airmasses with diverse sources and hence pollutant concentrations as seen by generalised back trajectory analysis, which suggests contributions from both local and long-range sources. Furthermore, back trajectory analysis demonstrates that the observed zonal gradients both in the boundary layer and the free troposphere are characteristic of marked changes in airmass history with distance offshore - coastal boundary layer airmasses having been in recent contact with the local land surface and remote maritime airmasses having resided over ocean for in excess of ten days. Boundary layer composition to the east of 75 degrees W was observed to be dominated by coastal emissions from sources to the west of the Andes, with evidence for diurnal pumping of the Andean boundary layer above the height of the marine capping inversion. Analysis of intra-campaign variability in atmospheric composition was not found to be significantly correlated with observed low-frequency variability in the large scale flow pattern; campaign-average interquartile ranges of CO, SO2 and O-3 concentrations at all longitudes were observed to dominate over much smaller differences in median concentrations calculated between periods of different flow regimes. The campaign climatology presented here aims to provide a valuable dataset to inform model simulation and future process studies, particularly in the context of aerosol-cloud interaction and further evaluation of dynamical processes in the SEP region for conditions analogous to those during VOCALS-REx. To this end, our results are discussed in terms of coastal, transitional and remote spatial regimes in the MBL and FT and a gridded dataset are provided as a resource.
Metrics
Details
- Title
- South East Pacific atmospheric composition and variability sampled along 20 degrees S during VOCALS-REx
- Creators
- G. Allen - University of ManchesterH. Coe - University of ManchesterA. Clarke - University of Hawaiʻi at MānoaC. Bretherton - University of WashingtonR. Wood - University of WashingtonS. J. Abel - Met OfficeP. Barrett - Met OfficeP. Brown - Met OfficeS. Freitag - University of Hawaiʻi at MānoaC. McNaughton - University of Hawaiʻi at MānoaS. Howell - University of Hawaiʻi at MānoaL. Shank - University of Hawaiʻi at MānoaV. Kapustin - University of Hawaiʻi at MānoaV. Brekhovskikh - University of Hawaiʻi at MānoaL. Kleinman - Brookhaven National LaboratoryY-N Lee - Brookhaven National LaboratoryS. Springston - Brookhaven National LaboratoryT. Toniazzo - University of ReadingR. Krejci - Stockholm UniversityJ. Fochesatto - University of Alaska FairbanksG. Shaw - University of Alaska FairbanksP. Krecl - University of LeedsB. Brooks - University of LeedsG. McMeeking - University of ManchesterK. N. Bower - University of ManchesterP. I. Williams - University of ManchesterJ. Crosier - University of ManchesterI. Crawford - University of ManchesterP. Connolly - University of ManchesterJ. D. Allan - University of ManchesterD. Covert - University of WashingtonA. R. Bandy - Drexel UniversityL. M. Russell - Scripps Institution of OceanographyJ. Trembath - Cranfield UniversityM. Bart - University of LeedsJ. B. McQuaid - University of LeedsJ. Wang - Brookhaven National LaboratoryD. Chand - University of Washington
- Publication Details
- Atmospheric chemistry and physics, v 11(11), pp 5237-5262
- Publisher
- Copernicus Gesellschaft Mbh
- Number of pages
- 26
- Grant note
- NE/F020465/1 / NERC; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC) European Southern Observatory (ESO) NE/F019874/1 / NERC; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC) ncas10009 / Natural Environment Research Council; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC) FORMAS agency
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemistry
- Web of Science ID
- WOS:000291636400009
- Scopus ID
- 2-s2.0-79957955954
- Other Identifier
- 991019167715804721
UN Sustainable Development Goals (SDGs)
This publication has contributed to the advancement of the following goals:
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- International collaboration
- Web of Science research areas
- Environmental Sciences
- Meteorology & Atmospheric Sciences