THE OCEANS PLAY A MAJOR ROLE IN THE CLIMATE SYSTEM BUT, AMONG THE FACTORS INFLUENCING CLIMATE CHANGE, THEY ARE PROBABLY THE LEAST UNDERSTOOD, BEING EXTREMELY CHALLENGING TO GATHER AND ANALYZE DATA ON THEM.
Oceans act like a massive solar panel that can retain heat and distribute it around the globe. They store and transport huge amounts of greenhouse gases, like carbon dioxide, and exchange them with the atmosphere and the lithosphere. By absorbing heat and fossil fuel emissions, the oceans slow down global warming and buffer its damaging effects. But they pay a high price for this, in terms of increasing temperatures, acidity, and stratification which in turn affect the distribution of animals and the way the ecosystem functions.
The ocean diffuses the effects of a temperature change for greater distances than solid land does. So when an area of the ocean becomes warmer or cooler than usual, it takes much longer for that area to revert to “normal” than it would for a land area. At the same time, an apparently small change in just one aspect of the ocean’s behaviour can produce major climate variations over large areas of the Earth.
The ocean’s currents are driven by variations in water density, caused by temperature (heating and cooling) and salinity (precipitation and evaporation) variation. The atmosphere strongly affects these density differences. More clouds, for example, mean that less sunlight (heat) reaches the water surface, and more precipitation can reduce the ocean’s surface salinity. Currents, often driven by these density differences, influence the climate by transporting heat and salinity. They can carry warmed or cooled water as far as several thousand kilometres, thus warming or cooling the air and, indirectly, the land far away.
Global ocean currents are particularly important in this process, because they can bring warmer water from lower latitudes towards the polar regions, (thus warming the atmosphere), cool and sink, and flow back towards the equator. This adds to the factors causing polar ice to melt.
Ocean observatories will lead to further insights on processes linking the oceans and the Earth’s climate. EMSO is there to provide the continuous monitoring capacity to track parameters related to climate change over the span of decades. EMSO fixed point observatories significantly enhance our marine environmental monitoring capabilities and increase our ability to respond adequately to major challenges related to environmental change.
Many of the EMSO facilities can continuously monitor variables related to ocean warming and climate change, such as water temperature or concentration of greenhouse gases like methane or carbon dioxide. Indeed they have been placed in diverse climatic areas, from the arctic to subtropics.
Climate change research themes:
ocean acidification, dynamics of water masses, deep underwater circulation, sea level rise.