Role and significance of biological processes in DMS release from ocean to atmosphere: a close examination of the black box

Objective

To assess sources and sinks of DMS in the North Sea and in the Mediterranean sea.


Once released to the atmosphere, DMS affects aerosol formation upon oxidation to various sulphur acids. Future changes in the ocean's pelagic ecosystem related to greenhouse warming of the earth will probably be modulated due to temperature-induced shifts in the network of production, transformation and utilisation processes that determine the concentration of DMS in the marine environment. It is known that only a fraction of the DMS in seawater reaches the air above it. Therefore, detailed information on environmental factors affecting the biological cycling of DMS is required to allow a proper assessment of the potential contribution of biogenic sources to the total sulphur load in the atmosphere.

It is intended to identify the environmental factors that govern the rate of DMS precursor production in key algal species e.g. Phaeocystis and the transformation processes that are determined by the producers themselves through algal enzymatic action and by the activity of bacteria and microflagellates, both in oxic and in anoxic microenvironments. The origin and fate of the oxidation product DMSO will be followed since its importance in the sulphur cycle cannot be assessed simply by concentration measurements.

Biological, physical and photochemical processes influencing the sea-to-air flux of DMS in the microlayer at the sea surface will receive special attention; the flux itself will be measured under controlled conditions in mesocosms for extrapolation to variety of field situations.

Finally, model simulations will be used to place all process rates in the context of the future changes in the marine environment that are expected due to human perturbations and consequences of these changes for the rate of DMS emissions to the atmosphere in the years to come.

Fields of science

• natural sciences › biological sciences › microbiology › bacteriology
• natural sciences › chemical sciences › electrochemistry › electrolysis
• natural sciences › biological sciences › ecology › ecosystems

Programme(s)

• FP3-ENV 1C - Specific research and technological development programme (EEC) in the field of the environment, 1990-1994

Topic(s)

• 0105 - Tropospheric physics and chemistry

Call for proposal

Data not available

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

UNIVERSITY OF GRONINGEN

Address

30,kerklaan 30
9751 NN Haren Gn
Netherlands

Participants (5)

Centre National de la Recherche Scientifique (CNRS)

France

Address

Avenue De La Terrasse
91198 Gif-sur-yvette

National Centre for Scientific Research 'Demokritos'

Greece

Address

Aghia Paraskevi, Attikis
15310 Athens

Netherlands Institute for Sea Research

Netherlands

Address

1790 AB Texel, Den Burg

UNIVERSITY OF EAST ANGLIA

United Kingdom

Address

University Plain
Norwich

Links

Universität Bremen

Germany

Address

28359 Bremen