The role of the oceans in climate

The oceans cover about 71% of the Earth’s surface and contain 97% of the Earth’s water (see Trenberth 2001). Through their fluid motions, their high heat capacity, and their ecosystems, the oceans play a central role in shaping the Earth’s climate and its variability. Changes in sea level have major impacts on coastal regions and storm surges. Accordingly, it is vital to monitor and understand changes in the oceans and their effects on weather and climate, and improve the verisimilitude of model ocean simulations. In this introduction, we outline these aspects and provide a justification for the ocean variables that should be observed and the networks and methods whereby this is achieved.