THe Role of ocEAnic halogen and sulfur compounds for The middle atmosphere in a changing climate”

Project Period: June 1st 2013 to May 31st 2016

Project Partners: GEOMAR Helmholtz Centre for Ocean Research Kiel and Karlsruhe Institute of Technology

Halogenated VSLS play a significant role in present day ozone depletion, in particular in combination with enhanced stratospheric sulfate aerosol concentrations. There is a need to better understand possible changes and feedbacks in a future climate especially under elevated sulfur levels in the stratosphere. The questions how much of the observed stratospheric halogen and sulfur aerosol abundances originate from natural sources, in particular from oceanic emissions, and how this will change and affect the structure and chemical composition of the middle atmosphere in a future climate are as yet unanswered and will be addressed within THREAT.

The main goals of THREAT are: I) to assess the role of naturally emitted short-lived halogen and sulfur compounds for the middle atmosphere in a changing climate (GEOMAR und KIT), II) to provide oceanic emission modules, which can be easily adapted to the new generation of coupled climate models (GEOMAR) and III) to improve the understanding and numerical modeling of the physical and chemical processes that control the delivery of VSLS and sulfur compounds to the stratosphere (GEOMAR und KIT).

To reach these goals, observed oceanic fluxes of halogenated VSLS and sulfur compounds will be parameterized to assess global oceanic emissions in present and future climate. The high resolution Lagrangian transport model FLEXPART and the coupled chemistry climate model EMAC will be applied to estimate the delivery of halogen and sulfur compounds to the middle atmosphere and to analyze possible feedback mechanisms.

Project–Partners (in alphabetical order):

Prof. Dr. Kirstin Krüger (Initiator and counselor of the project: now at University of Oslo)
Gisele Krysztofiak (EMAC Modelling: Post Doc, KIT)
Sinikka Lennartz (Global modeling of oceanic emissions: PhD, GEOMAR)
Prof. Dr. Christa Marandino (Oceanic Sulfur Emissions:  Co Manager, GEOMAR)
Dr. Birgit Quack (Oceanic Halogen Emissions:  Project Coordinator, GEOMAR)
Dr. Björn-Martin Sinnhuber (EMAC Modelling, Co-Investigator, KIT)
Dr. Susan Tegtmeier (FLEXPART Modelling:  Post Doc, GEOMAR)


Dr. Birgit Quack
Chemical Oceanography
GEOMAR Helmholtz Centre for Ocean Research Kiel

Dr. Björn-Martin Sinnhuber
Institute for Meteorology and Climate Research IMK-ASF
Karlsruhe Institute of Technology (KIT)