Summary of Abstract Submission

Abstract Submission No. IO50-05-0011PresentationOral

ORGANIC VERY SHORT LIVED SUBSTANCES AND THEIR AIR SEA EXCHANGE FROM THE INDIAN OCEAN TO THE STRATOSPHERE

Quack, Birgit*1, Hepach, Helmke1, Atlas, Elliot2, Fiehn, Alina1, Marandino, Christa1, Lennartz, Sinikka1, Waersted, Eivind3, Bracher, Astrid4, Krueger, Kirstin3

1 GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
2 Rosenstiel School of Marine and Atmospheric Sciences, Miami, Germany
3 University of Oslo, Norway
4 Alfred-Wegener-Institut für Polar- und Meeresforschung, Germany

ABSTRACT :

Within the frame work of the project OASIS the research cruises SO234-2 (Durban- Port Louis, 08-20 July, 2014) and SO235 (Port Louis ¿ Male, July 23 to August 07, 2014) of the German research vessel SONNE were conducted by the University of Oslo, Norway (www.uio.no) together with the GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany (www.geomar.de) in the subtropical and tropical West Indian Ocean. The research covered the air- sea gas exchange of a suite of natural and anthropogenic short- and long lived trace gases as well as atmospheric composition and transport. Very short lived substances such as bromoform, dibromomethane and methyl iodide, which are naturally produced in the oceans and influence stratospheric ozone and climate, were investigated. The Asian monsoon circulation provides an effective pathway for air masses from the atmospheric boundary layer containing these and other compounds to enter the global stratosphere during boreal summer especially above India and Bay of Bengal. During the cruises biological, chemical and physical parameters in surface waters and the deep ocean, the oceanic emissions, their transport to the stratosphere and their contribution to the stratospheric halogen budget, deduced from radiosonde launchings and high resolution transport modelling, were determined. The measurements were conducted in various marine biogeochemical regimes close to coasts, coral reefs and sea banks, high chlorophyll and oligotrophic regimes. Here we present an overview of the research during the cruises and some novel results.