An empirical sun-glint index for GOME-2
Beirle, Steffen; Penning de Vries, Marloes; Wagner, Thomas

Sun-glint has high impact on several kinds of remote sensing applications over oceans, e.g. ocean color, detection of oil spills, retrieval of cloud and aerosol properties, or the retrieval of trace gas columns from spectral measurements. Here we investigate to what extent information about sun-glint occurence can be derived from spectrally resolved measurements from satellite, e.g. GOME-2, covering the UV/vis spectral range, but with rather coarse spatial resolution. Several different quantities are investigated, e.g. radiance, different colour indices, polarization, measured oxygen column, or Raman scattering. From the combination of these quantities, it is possible to differentiate sun-glint from clouds, and an empirical sun-glint index can be defined. This might serve as a simple sun-glint flag, either to exclude or select sun-glint situations for their well-defined radiative transfer conditions. Beyond, the sun-glint index might allow for a more gradual quantification or correction of sun-glint effects, with potential applications in various fields of research.