To produce a module that may serve as the interface between atmospheric
circulation and ocean circulation calculations to generate the
necessary coupling through transfer of momentum, energy and
The "Interfacial Module" will require calculation of the
surface-wave field, which in turn needs solution of a transport
equation for the two-dimensional wave spectrum. The transport
equation has source and sink terms related to wind input and
dissipation, and therefore depends on the spatio temporal history
of atmospheric conditions, e.g. of the wind. This development
will represent an advance over the current state of the art in
which the coupling is calculated without considering the ocean
The work involves a number of parallel investigations, carried
out by an interdisciplinary team of atmospheric scientists, fluid
dynamicists and chemical engineers :
A database of relevant experimental data will be established.
This will involve the acquisition, examination and selection of
data from existing wind tunnel/wave tank and open ocean
experiments. Data from which the surface wave field can be
reasonably estimated or was directly measured will be included.
Submodels, based on existing data, will be developed for each of
the fluxes, i.e. for momentum, sensible heat, latent heat/water
vapour, droplet and CO2.
Numerical simulation (based on Large Eddy Simulation, LES, and
analytic models) of wind flow over representative wave profiles
will be performed for a set of stable, neutral and unstable
conditions to better understand the mechanisms governing the
air-side fluxes and droplet motion and evaporation.
Existing and ongoing experiments generating information on bubble
entrainment and drop formation will be assessed. Dropsizes and
ejection velocities will be correlated, and the effect of drops
and bubbles on gas and water vapour transfer rates will be
The submodels will be integrated with a global wave model. The
combined wave-coupling flux model will be the main product of the
programme (i.e. the ocean-atmosphere coupling module).
The module is to be validated against experiments of various
scales and should be suitable for use in century-long
integrations of coupled ocean-atmosphere climate models.
Funding SchemeCSC - Cost-sharing contracts
20090 Segrate Milano
19100 La Spezia
SW7 2AZ London
RG12 2SZ Bracknell
RG6 2AU Reading / Silchester