ROTATIONAL RAMAN-SCATTERING (RING EFFECT) IN SATELLITE BACKSCATTER ULTRAVIOLET MEASUREMENTS

A detailed radiative transfer calculation has been carried out to esti mate the effects of rotational Raman scattering (RRS) on satellite mea surements of backscattered ultraviolet radiation. Raman-scattered ligh t is shifted in frequency from the incident light, which causes fillin g in of solar Fraunhofer lines in the observed backscattered spectrum (also known as the Ring effect). The magnitude of the rotational Raman scattering filling in is a function of wavelength, solar zenith angle , surface reflectance, surface pressure, and instrument spectral resol ution. The filling in predicted by our model is found to be in agreeme nt with observations from the Shuttle Solar Backscatter Ultraviolet Ra diometer and the Nimbus-7 Solar Backscatter Ultraviolet Radiometer.