Within the geophysical retrieval algorithm for AIRS/AMSU/HSB, a forward radiative transfer model is used to calculate microwave brightness temperatures. Components of the microwave forward model include a surface emissivity model, the influence of surface scattering characteristics on reflected downwelling emission from the atmosphere, and an atmospheric transmittance model. Over the ocean, the surface model parameters are shown to be related to near-surface wind speed. Calculations using the atmospheric transmittance model with profiles from dedicated radiosondes launched underneath the Aqua satellite show good agreement with HSB measurements.