EGU23-6381, updated on 06 May 2024
https://doi.org/10.5194/egusphere-egu23-6381
EGU General Assembly 2023
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Halocarbon dynamics from Las Palmas to Guayaquil in winter 2021/2022 – Results of SO287-CONNECT

Birgit Quack1, Dennis Booge2, Helmke Hepach3, Elliot Atlas4, Josefine Karnatz5, Alexandra Rosa6, Claudio Cardoso7, Stephen Ball8, Philippe Potin9, and Rüdiger Röttgers10
Birgit Quack et al.
  • 1GEOMAR Helmholtz Centre for Ocean Research Kiel, Marine Biogeochemistry - Chemical Oceanography, Kiel, Germany (bquack@geomar.de)
  • 2GEOMAR Helmholtz Centre for Ocean Research Kiel, Marine Biogeochemistry - Chemical Oceanography, Kiel, Germany (dbooge@geomar.de)
  • 3GEOMAR Helmholtz Centre for Ocean Research Kiel, Marine Biogeochemistry - Biological Oceanography, Kiel, Germany (hhepach@geomar.de)
  • 4Rosenstiel School of Marine, Atmospheric, and Earth Science Department of Atmospheric Sciences, University of Miami, Miami, FL. USA (eatlas@miami.edu)
  • 5GEOMAR Helmholtz Centre for Ocean Research Kiel, Marine Biogeochemistry - Biological Oceanography, Kiel, Germany (jkarnatz@geomar.de)
  • 6Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação, Observatório Oceânico da Madeira, Funchal, Portugal (alexandra.rosa@oom.arditi.pt)
  • 7A) Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação, Observatório Oceânico da Madeira, Funchal, Portugal. B) Universidade de Lisboa, Faculdade de Ciências, Instibtuto Dom Luiz, Lisboa, Portugal. C) Helmholtz-Zentrum Hereon,
  • 8University of Leicester, School of Chemistry, Leicester, LE1 7RH, United Kingdom (sb263@leicester.ac.uk)
  • 9Sorbonne Université, CNRS, Station Biologique de Roscoff, Laboratory of Integrative Biology of Marine Models (philippe.potin@sb-roscoff.fr)
  • 10Helmholtz Centre Hereon, Institute of Carbon Cycles, Optical Oceanography (ruediger.roettgers@hereon.de)

Short-lived bromo-, chloro- and iodocarbons from marine and anthropogenic sources contribute to the atmospheric halogen budgets and to ozone depletion in the troposphere and stratosphere. Their spatial variations are poorly known, given the sparse observations of marine and atmospheric concentrations. The distribution and air-sea fluxes of halocarbons need to be quantified in order to clarify the oceanic contributions to future tropospheric and stratospheric ozone chemistry.

Here we present the first marine and atmospheric halocarbon dataset from the research cruise SO287-CONNECT (Pan-Atlantic connectivity of marine biogeochemical and ecological processes and the impact of anthropogenic pressures). The transit of RV SONNE from Las Palmas, Spain (departure: 11.12.2021) to Guayaquil, Ecuador (arrival: 11.01.2022) was conducted to decipher the coupling of biogeochemical and ecological processes and their influence on atmospheric chemistry along the transport pathway of water from the upwelling zones off Africa into the Sargasso Sea and further to the Caribbean and the equatorial Pacific. A comprehensive work program, which combined continuous underway and station work, marine and atmospheric measurements and sampling with incubation experiments was conducted.

The distribution of short-lived halocarbons, e.g. bromoform (CHBr3), dibromomethane (CH2Br2), methyl iodide (CH3I), and trichloromethane (CHCl3) was highly dynamic in both ocean and atmosphere. We calculate the air-sea exchange of the compounds and relate physical and biological parameters to our observations. Among these are transport processes (e.g. long-range transport, eddies) and we show the varying composition of air and water masses and the potential sources of the compounds. For the first time, we estimate the contribution of the floating macroalgae Sargassum to halocarbon cycling around the North Atlantic gyre and in the Caribbean. The evaluation of the comprehensive data set collected during SO287-CONNECT improves our knowledge on the general role of the great Atlantic Sargassum belt and anthropogenic pollution in elemental biogeochemical cycles, as well as on trace gas exchange across the ocean-atmosphere interface.

How to cite: Quack, B., Booge, D., Hepach, H., Atlas, E., Karnatz, J., Rosa, A., Cardoso, C., Ball, S., Potin, P., and Röttgers, R.: Halocarbon dynamics from Las Palmas to Guayaquil in winter 2021/2022 – Results of SO287-CONNECT, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6381, https://doi.org/10.5194/egusphere-egu23-6381, 2023.