Geoscience Reference
In-Depth Information
3
Ocean-Atmosphere Interactions
3.1. Introduction: what are ocean-atmosphere interactions?
Ocean-atmosphere interactions involve exchanges of heat, mass
(water) and chemical components. They bring mechanisms at different
scales into play, from thermal conduction in water and air to coupling
phenomena involving the entire atmosphere and upper layers of the
ocean, such as tropical cyclones.
The essential source of energy for the Earth is the Sun. The Sun's
radiation is centered in the visible domain, which reaches the Earth's
surface after penetrating the atmosphere. The sea surface reflects some
of this radiation, while the remaining radiation penetrates
the ocean surface. The light can penetrate several tens of meters the
ocean surface, allowing a transfer of energy into the upper layers of
the sea. This heat supplied to the ocean can be transported by currents
or redistributed into the atmosphere by means of heat exchanges or
evaporation, which supplies the atmosphere with water vapor. The
presence of surface inhomogeneities, such as oceanic fronts
(variations in surface temperature over a few tens of kilometers) or sea
ice, leads to horizontal variations in ocean-atmosphere exchanges.
Wind friction, as well as the transfer of heat between ocean and
atmosphere, is strongly amplified and accelerated by atmospheric
turbulence on the smallest of scales. Vertical displacements of air or
