Quantification of oceanic sources and sinks of organic halogens
During primary production so-called byproducts are released to the environment. Among these are organic halogens that can ultimately lead to ozone destruction in the atmosphere. To quantify the fluxes of organic halogens between ocean and atmosphere all sources and sinks need to be accounted for, considering the potentially large spatial and temporal variability. Consequences of climate change on the air-sea flux have to be evaluated. We address these aspects in the subproject “Modelling of organohalogen trace gases in the tropical Atlantic atmosphere and ocean“ led by the University of Hamburg and the Max Planck Institute of Meteorology (joint BMBF-project SOPRAN: Surface Ocean Processes in the Anthropocene; the German contribution to SOLAS: Surface Ocean Lower Atmosphere Studies). We have conducted simulation experiments with a coupled global biogeochemical - general ocean circulation model (HAMOCC - MPIOM) in which we explicitly include organic halogens. Our simulated global distribution patterns and air-sea fluxes of organic halogens have been compared with observations and show good overall agreement (Stemmler et al. 2013; Stemmler et al. 2014).
Participating team members:
Irene Stemmler, Inga Hense
Stemmler, I., Hense, I., Quack, B., and Maier-Reimer, E. (2013). Methyl iodide production in the open ocean. Biogeosciences Discussions, 10, 17549-17595.
Stemmler I., M. Rothe and I. Hense (2013). Numerical modelling of methyl iodide in the Eastern Tropical Atlantic. Biogeosciences, 10, 4211-4225, doi:10.5194/bg-10-4211-2013.
Hense I. and B. Quack (2009): Modelling the vertical distribution of bromoform in the upper water column of the tropical Atlantic Ocean. Biogeosciences, 6, 535–544.