A relationship between atmospheric rain reflectivity and elevation variance due to drop impact on the sea surface

The additional surface roughness created by drops impacting the sea surface can bias wind speed estimates obtained from satellite scatterometric measurements. The additional roughness essentially depends on the rain content in very large drops. The estimate of this contribution will be highly dependent on the model chosen for the drop size distribution. However, it has been observed that the reflectivity of the drops falling in the atmosphere has a drop-size dependence that is very similar to that of the surface roughness induced by rain. This paper shows how reflectivity data can be used to improve the estimate of the elevation variance resulting from drop impact.