Exchange of carbon dioxide between atmosphere and the Baltic sea

Introduction

The global carbon cycle and the exchange of carbon dioxide (CO₂) between the atmosphere and the terrestrial biosphere as well as the ocean are directly related to the climate of the earth. Human activities like burning of fossil fuels have increased the emissions of CO₂ to the atmosphere during the last few hundred years. Effects suggested due to increasing atmospheric CO₂ concentrations are increased mean surface temperature and precipitation. This may lead to shifts in the carbon cycle and it is therefore important to study the emissions/sinks of greenhouse gases in aquatic systems in a changing climate perspective. The role of the terrestrial biosphere and the ocean as sinks for anthropogenic CO₂ is of high importance and the role of the coastal and marginal seas has been much neglected. However, in recent times its importance has been re-evaluated.

The area of study, the Baltic Sea, is an adjacent sea to the Atlantic Ocean, with very limited seawater exchange but intense land-sea interaction. The water is brackish with the highest salinity in the southern part, decreasing northwards.

Objectives

The objective of this research is to increase the understanding of the processes relevant for the exchange of CO₂ between the atmosphere and the ocean. Achieve better air-sea flux estimates of CO₂ for the Baltic Sea at present and to use historic data to elucidate how these fluxes possibly have changed during the last 50-70 years.

Methods

Carbon system data as well as auxiliary data like nutrient and oxygen will be collected during cruises between Göteborg and Skagen as well as in the Baltic Sea. The data collected will be used to construct box models for the quantification of CO₂ gas exchange. The model will then be applied to historical data to estimate changes over time.
Cooperations

The project is a cooperation between our department (Department of Chemistry, Göteborg University), the Finnish Institute of Marine Research in Helsinki and the Baltic Sea Research Institute in Warnemünde. There will also be co-operations with the department of Oceanography, Göteborg University and the department of Metrology, Uppsala University.