Halogenated trace gases from the ocean to the atmosphere (Halocarbons)

The gradual recovery of the ozone layer is expected over the next decades due to the reduction of anthropogenic emissions of long-lived chlorofluorocarbons following the Montreal Protocol of 1987. The sources of oceanic very short-lived halocarbons (e.g. of bromoform, CHBr3) and their influence on ozone, on the other hand, are increasing. The Halocarbon group investigates the distribution and biogeochemical cycling of natural and anthropogenic halocarbons from various sources (phytoplankton, macro algae, disinfection processes) in the ocean in cooperation with biologists and their air- sea exchange. In cooperation with oceanic and atmospheric modellers, regional and global, spatial and temporal data gaps are closed in order to clarify the oceanic contributions to future tropospheric and stratospheric ozone chemistry.

Research interests

  • Marine biogeochemistry of halogenated methanes and their impact on the atmosphere
  • Control factors of marine trace gas emissions
  • Oceanography of volatile halogenated hydrocarbons in the ocean
  • Sources and emissions of marine brominated and iodinated compounds
  • Natural and anthropogenic sources of bromoform (CHBr3)
  • Marine cycles of chlorinated compounds
  • The utilisation of macroalgae
  • Analysis of natural and anthropogenic halogenated hydrocarbons in the ocean and atmosphere on land and on ships
  • Drones in use for research into marine trace gas emissions
  • Plastic waste in the ocean - preventing entry, recognising and using resources


The work of the Halocarbon group aims at the identification of the main driving factors for the regional and temporal variability of marine halocarbon distributions and emissions and their impact in the troposphere and stratosphere. The tropical oceans are of special significance, as most tropospheric trace gases, including the oceanic emissions of the short-lived halocarbons, enter the stratosphere in the tropics. They are transported towards the winter pole by large-scale circulation in the stratosphere, finally descending to the troposphere at mid and high latitudes again. Hence, tropical processes impact the chemical composition of the entire atmosphere. In the projects SOPRAN, TRANSBROM, SHIVA, ROMIC-THREAT, OASIS, and Astra- OMZ, oceanic halocarbon distributions, sources, their air-sea exchange, transport through the atmosphere and impact on the stratosphere were investigated. The interdisciplinary cooperation with atmospheric chemists and physicists, biologists and biogeochemical modelers, currently further investigates ” Threats to Ozone Recovery from Anthropogenic Emissions of ‘Very Short-lived’ Halocarbons” and the  “Biological control of climate-active trace gases in the surface ocean”.

AIMAC was a three weeks expedition with RV Poseidon on atmosphere-ocean-island-biogeochemical cycles in the Macaronesian region in March 2019 and captured natural and anthropogenic interactions between Madeira, the Canary Islands and Cape Verde, and the open ocean and atmosphere.



Science team on Transbrom in 2009

Its a snowflake and its hot on SO287

Going on board for SO287 in December 2021 during Corona

Airsampling during POS533 off Sao Vicente

Deploying CTDs on SO287

Going off board RV SONNE

Incubating Sargassum for halocarbon and DOC release

Jesus operating the CTD during POS533

Kicki and Susi, launching radiosondes during Transbrom in 2009

Labeling the bottles during POS533 by Claudio

Launching an ozonesonde on SO287

Melina, Helmke and Dennis on POS533 in 2019

Philippe and Josi catching their first Sargassum on Christmas eve druing SO287

Riel is announcing the New Year from the Philippines on board SO287 during lunch

Philippe and Frank fished Sargassum with a net when it was too wavy for the Zodikak

Setup for SO287 in the hangar

Tabletennis winner put the cruise sticker of SO287 to the others

Taking deep water samples

Test of fire sirene on old RV SONNE during Transbrom in 2009_Tilmann Dinter, who sadly died in an accident in 2023

Unpacking for GC/MS measurements in the wet lab of RV SONNE


Working Group

  • Head of Working Group

    Dr. Birgit Quack
    GEOMAR Helmholtz Centre
    for Ocean Research Kiel
    Wischhofstrasse 1-3
    24148 Kiel
    Tel.: +49 431-600-4206
    E-Mail: bquack(at)geomar.de

  • Elliot Atlas
    Dennis Booge
    Patrice Brehmer
    Ndague Diogoul
    Mamie Souadou Diop
    Helmke Hepach
    Julia Mickenbecker
    Waly Ndiaye
    Jule Ploschke
    Susann Tegtmeier
    Lewin Schmidt
    Florian Weinberger

  • Claudio Cardoso
    Sonja Endres
    Alina Fiehn
    Steffen Fuhlbrügge
    Inga Hense
    Yue Jia
    Kristin Krüger
    Atul Kumar
    Josephine Maas
    Gert Petrick
    Klaus Pfeilsticker
    Jesus Reis
    Alexandra Rosa
    Irene Stemmler
    Douglas Wallace
    Franziska Ziska