Underway water measurements of halocarbons during POSEIDON cruise POS399 in June 2010

Methyl iodide (CH3I), bromoform (CHBr3) and dibromomethane (CH2Br2), which are produced naturally in the oceans, take part in ozone chemistry both in the troposphere and the stratosphere. The significance of oceanic upwelling regions for emissions of these trace gases in the global context is still uncertain although they have been identified as important source regions. To better quantify the role of upwelling areas in current and future climate, this paper analyzes major factors that influenced halocarbon emissions from the tropical North East Atlantic including the Mauritanian upwelling during the DRIVE expedition. Diel and regional variability of oceanic and atmospheric CH3I, CHBr3 and CH2Br2 was determined along with biological and meteorological parameters at six 24 h-stations. Low oceanic concentrations of CH3I from 0.1-5.4 pmol/L were equally distributed throughout the investigation area. CHBr3 of 1.0-42.4 pmol/L and CH2Br2 of 1.0-9.4 pmol/L were measured with maximum concentrations close to the Mauritanian coast. Atmospheric mixing rations of CH3I of up to 3.3, CHBr3 to 8.9 and CH2Br2 to 3.1 ppt above the upwelling and 1.8, 12.8, respectively 2.2 ppt at a Cape Verdean coast were detected during the campaign. While diel variability in CH3I emissions could be mainly ascribed to oceanic non-biological production, no main driver was identified for its emissions in the entire study region. In contrast, oceanic bromocarbons resulted from biogenic sources which were identified as regional drivers of their sea-to-air fluxes. The diel impact of wind speed on bromocarbon emissions increased with decreasing distance to the coast. The height of the marine atmospheric boundary layer (MABL) was determined as an additional factor influencing halocarbon emissions. Oceanic and atmospheric halocarbons correlated well in the study region and in combination with high oceanic CH3I, CHBr3 and CH2Br2 concentrations, local hot spots of atmospheric halocarbons could solely be explained by marine sources. This conclusion is in contrast with previous studies that hypothesized the occurrence of elevated atmospheric halocarbons over the eastern tropical Atlantic mainly originating from the West-African continent.

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Hepach, Helmke, Quack, Birgit, Ziska, Franziska, Fuhlbruegge, Steffen, Atlas, Elliot L, Krüger, Kirstin, Peeken, Ilka, Wallace, Douglas WR (2014). Dataset: Underway water measurements of halocarbons during POSEIDON cruise POS399 in June 2010. https://doi.org/10.1594/PANGAEA.777300

DOI retrieved: 2014

Additional Info

Field Value
Imported on November 30, 2024
Last update November 30, 2024
License CC-BY-3.0
Source https://doi.org/10.1594/PANGAEA.777300
Author Hepach, Helmke
Given Name Helmke
Family Name Hepach
More Authors
Quack, Birgit
Ziska, Franziska
Fuhlbruegge, Steffen
Atlas, Elliot L
Krüger, Kirstin
Peeken, Ilka
Wallace, Douglas WR
Source Creation 2014
Publication Year 2014
Resource Type text/tab-separated-values - filename: hepach-etal_2014
Subject Areas
Name: Atmosphere

Name: Chemistry

Related Identifiers
Title: Drivers of diel and regional variations of halocarbon emissions from the tropical North East Atlantic
Identifier: https://doi.org/10.5194/acp-14-1255-2014
Type: DOI
Relation: IsSupplementTo
Year: 2014
Source: Atmospheric Chemistry and Physics
Authors: Hepach Helmke , Quack Birgit , Ziska Franziska , Fuhlbruegge Steffen , Atlas Elliot L , Krüger Kirstin , Peeken Ilka , Wallace Douglas WR .

Title: FS Poseidon Fahrtbericht / Cruise Report P399 - 2&3: Eastern tropical North Atlantic ; P399-2: 31.04.2010-17.06.2010 Las Palmas - Las Palmas (Canary Islands), P399-3: 18.-24.06.2010 Las Palmas (Canary Islands) - Vigo (Spain) ; DRIVE (Diurnal and RegIonal Variability of Halogen Emmissions), SOPRAN
Identifier: https://doi.org/10.3289/ifm-geomar_rep_48_2011
Type: DOI
Relation: References
Year: 2011
Source: IFM-GEOMAR Report
Authors: Bange Hermann Werner , Bange Hermann Werner , Quack Birgit , Fuhlbruegge Steffen , Krüger Kirstin , Quack Birgit , Atlas Elliot L , Hepach Helmke , Ziska Franziska , Quack Birgit , Hepach Helmke , Atlas Elliot L .

Title: Diurnal and regional variability of halogen emissions off Mauritania: The DRIVE ship campaign in June 2010
Type: DOI
Relation: References
Year: 2011
Source: SOLAS news
Authors: Bange Hermann Werner , Bange Hermann Werner , Quack Birgit , Fuhlbruegge Steffen , Krüger Kirstin , Quack Birgit , Atlas Elliot L , Hepach Helmke , Ziska Franziska , Quack Birgit , Hepach Helmke , Atlas Elliot L .

Title: Underway measurements of halocarbons (air) during POSEIDON cruise POS399 in June 2010
Identifier: https://doi.org/10.1594/PANGAEA.855314
Type: DOI
Relation: References
Year: 2013
Authors: Bange Hermann Werner , Bange Hermann Werner , Quack Birgit , Fuhlbruegge Steffen , Krüger Kirstin , Quack Birgit , Atlas Elliot L , Hepach Helmke , Ziska Franziska , Quack Birgit , Hepach Helmke , Atlas Elliot L .

Title: Measurements of halocarbons at the Cape Verde Atmospheric Observatory (CVAO) during POSEIDON cruise POS399/2
Identifier: https://doi.org/10.1594/PANGAEA.855334
Type: DOI
Relation: References
Year: 2015
Source: IFM-GEOMAR Leibniz-Institute of Marine Sciences, Kiel University
Authors: Bange Hermann Werner , Bange Hermann Werner , Quack Birgit , Fuhlbruegge Steffen , Krüger Kirstin , Quack Birgit , Atlas Elliot L , Hepach Helmke , Ziska Franziska , Quack Birgit , Hepach Helmke , Atlas Elliot L .