J.Polcher 
,
B. McAvaney 
,
P. Viterbo 
,
M.-A. Gaertner 
,
A. Hahmann 
,
J.-F. Mahfouf ,
J. Noilhan 
,
T. Phillips 
,
A. Pitman 
,
C.A. Schlosser 
,
J.-P. Schulz 
,
B. Timbal ,
D. Verseghy 
and
Y. Xue 
March 6, 1998
The aim of this paper is to propose a general interface for coupling general circulation models (GCMs) to land-surface schemes in order to achieve a plug compatibility between these complex models. As surface parameterizations included more processes they have moved from being subroutines to GCMs to independent schemes which can also be applied for other purposes. This evolution has raised the problem within climate modeling groups of coupling these schemes to GCMs in a simple and flexible way. The larger independence land-surface schemes have reached makes it possible to exchange them within the community which also calls for a general interface. This paper discusses the tasks land-surface schemes have to fulfill when coupled to a GCM after a review of the current state of the art and the likely future evolutions of both components. The numerical schemes used for the processes which couple the land-surfaces to the atmosphere are reviewed to ensure that the interface can be applied to all land-surface schemes and GCMs after only minor changes.
Keywords : PILPS, Land-surface schemes, general circulation models, coupling Land-surface schemes.