Ocean–Atmosphere Interactions - Ocean in the Earth System - page 106

water parcels are linked to horizontal movements (wind and current)
and to a vertical temperature or humidity gradient. In parallel,
the wind friction at the surface triggers local phenomena (waves,
or even sea spray and bubbles when the waves break), which
themselves influence exchanges of energy and matter between the
water and air.

Moreover, the ocean and the atmosphere exchange matter: water
(by evaporation and precipitation), gases and solid particles. Gas
exchanges depend on the wind speed and water temperature (through
the gases' solubility). The deposited particles are carried, through the
atmosphere, from the continents by dry deposition or dissolved inside
rain drops; the emitted particles result from the evaporation of sea-
water from sea spray (“primary” aerosols), and also, more indirectly,
from the chemical transformation of gases issuing from organic
components of surface water (DiMethyle Sulfure (DMS) or organic
volatile components), in particular inside clouds.

First, we will summarize the physics of air-sea exchanges of
energy and matter. Then we will show, using a few examples, how
these processes intervene in the ocean-atmosphere coupling on
different scales.

3.2. Interface processes and their role in the coupled system

In this section, we will summarize the bases of the processes
involved and their formulation. We will show how exchanges of
energy and matter are involved in the ocean-atmosphere coupling and
then we will give the main approaches to measure them.

A surface energy flux is the quantity of energy that crosses a unit
of the surface in 1 second. It is expressed in Watts per meter squared.
The energy balance at the surface can be written as:

G = Rnet - Fturb [3.1]

with:
- G : flux penetrating the ocean;