In this study, we investigate the capability to retrieve cloud parameters from near-ultraviolet, visible, and near-infrared satellite-based reflectivity measurements. These parameters are essential to enable trace gas retrievals for cloud-contaminated satellite scenes. We compare the retrieval of cloud top pressure, cloud fraction, and cloud optical thickness from simulated reflectivity measurements in three wavelength ranges: (1) 350-400 nm, which includes pronounced Ring effect structures; (2) 460-490 nm; and (3) 755-775 nm, which contain absorption features of O2-O2 and O2, respectively. Retrieval simulations are performed for both a typical noise level of present-day space-borne spectrometers and additional random-like measurement biases. Furthermore, we investigated the importance of the spectral continuum for the retrieval of cloud properties. It is found that reflectivity measurements in the wavelength ranges 350-400 and 755-775 nm provide complementary information on cloud properties. Both spectral windows provide more information on clouds than the 460-490 nm window. The best results are obtained for the combination of the 350-400 and 755-775 nm windows. In this case all three cloud parameters can be retrieved independently, and a high robustness is obtained with respect to random-like measurement biases. Here it is not required to resolve the Ring effect structures in the near-ultraviolet window. For this combination of spectral windows the error on retrieved NO2 columns is reduced considerably.
