Atmosphere and ocean interaction: ocean circulation and heat content evolution in millennial climate simulations.

Progress in understanding climate variability and change depends on our knowledge of the transport mechanisms and energy and matter (e. g. freshwater and chemical components) exchanges among the different components of the climate system. Through their energy and mass interactions with the other components of the climate system (atmosphere, cryosphere, biosphere and lithosphere) the oceans act as important pacemakers of climate variability in a wide spectrum of frequencies, from interannual to glacial time scales. The oceans, for instance, store and transport around heat through convection and advection, the latter by means of eddies at different spatial scales in ocean currents. Therefore, heat exchanged at the surface and stored for varying durations and released in different places; thereby ameliorating temperature changes with a thermal regulator effect over continents and contributing substantially to variability of climate on different time scales. Within a latitude band embracing the tropical regions of both hemispheres the net radiative balance at the top of the atmosphere is positive whereas it i