The question of the surface-wave energy balance turns 

 out to be closely related to the problem of remote sea- 

 surface sensing, which is considered in the second part of 

 this paper. One of the goals of remote measurements from 

 satellites is to obtain synoptic data of sea state and, if 

 possible, surface winds as input for wave and weather fore- 

 casts. The quality of data needed for this purpose is 

 determined by the numerical prediction model used, which in 

 the case of surface waves is governed by the structure of 

 the spectral energy balance. More importantly, the inter- 

 pretation of microwave signals emitted or scattered from the 

 sea surface is intimately dependent on the details of the 

 dynamical interactions affecting the energy balance of the 

 wave spectrum. This applies both to measurements of the 

 sea state itself as also to the determination of the wave- 

 induced noise in measurements of other properties of the sea 

 surface, such as the microwave temperature or the mean 

 surface elevation. 



The relevance of dynamical processes for the — appar- 

 ent purely klnematical — problem of determining sea state 

 results from a basic difficulty besetting microwave measure- 

 ments: the pronounced wavelength mismatch between the 

 sensing radiation and the wave field being sensed. This 

 precludes determining the surface wave spectrum directly by 



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