Underway measurements of halocarbons (air) during POSEIDON cruise POS399 in June 2010, supplement to: Fuhlbruegge, Steffen; Krüger, Kirstin; Quack, Birgit; Atlas, Elliot L; Hepach, Helmke; Ziska, Franziska (2013): Impact of the marine atmospheric boundary layer conditions on VSLS abundances in the eastern tropical and subtropical North Atlantic Ocean. Atmospheric Chemistry and Physics, 13(13), 6345-6357

DOI

During the DRIVE (Diurnal and Regional Variability of Halogen Emissions) ship campaign we investigated the variability of the halogenated very short-lived substances (VSLS) bromoform (CHBr3), dibromomethane (CH2Br2) and methyl iodide (CH3I) in the marine atmospheric boundary layer in the eastern tropical and subtropical North Atlantic Ocean during May/June 2010. The highest VSLS mixing ratios were found near the Mauritanian coast and close to Lisbon (Portugal). With backward trajectories we identified predominantly air masses from the open North Atlantic with some coastal influence in the Mauritanian upwelling area, due to the prevailing NW winds. The maximum VSLS mixing ratios above the Mauritanian upwelling were 8.92 ppt for bromoform, 3.14 ppt for dibromomethane and 3.29 ppt for methyl iodide, with an observed maximum range of the daily mean up to 50% for bromoform, 26% for dibromomethane and 56% for methyl iodide. The influence of various meteorological parameters - such as wind, surface air pressure, surface air and surface water temperature, humidity and marine atmospheric boundary layer (MABL) height - on VSLS concentrations and fluxes was investigated. The strongest relationship was found between the MABL height and bromoform, dibromomethane and methyl iodide abundances. Lowest MABL heights above the Mauritanian upwelling area coincide with highest VSLS mixing ratios and vice versa above the open ocean. Significant high anti-correlations confirm this relationship for the whole cruise. We conclude that especially above oceanic upwelling systems, in addition to sea-air fluxes, MABL height variations can influence atmospheric VSLS mixing ratios, occasionally leading to elevated atmospheric abundances. This may add to the postulated missing VSLS sources in the Mauritanian upwelling region (Quack et al., 2007).

Identifier
DOI https://doi.org/10.1594/PANGAEA.855314
Related Identifier https://doi.org/10.5194/acp-13-6345-2013
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.855314
Provenance
Creator Fuhlbruegge, Steffen; Krüger, Kirstin; Quack, Birgit; Atlas, Elliot L; Hepach, Helmke; Ziska, Franziska
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2013
Rights Data access is restricted (moratorium, sensitive data, license constraints)
OpenAccess false
Representation
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 7351 data points
Discipline Earth System Research
Spatial Coverage (-24.308W, 17.596S, -9.509E, 40.244N); Eastern Tropical North Atlantic
Temporal Coverage Begin 2010-06-03T23:00:00Z
Temporal Coverage End 2010-06-23T11:58:00Z