Summary
New techniques have been developed to aid in the remote sensing of type II Polar Stratospheric Clouds (PSCs) using NASA’s MODIS (MODerate resolution Imaging Spectroradiometer) nadir imaging satellite. A number of cases of likely PSC occurrence were identified from ground-based photographs displaying nacreous colours typical of type II water ice PSCs, and compared with MODIS imagery. These cases were verified to contain PSCs using radiosonde data and knowledge of prevailing meteorological conditions. MODIS channels 29, 31 and 32 were used to construct colour-colour plots, with data points taken from cloudy regions. A hybrid Eddington single-scattering radiative transfer model was used to model the top-of-atmosphere radiance due to the cloud. The model results were compared to the observed top-of-atmosphere radiance as measured by MODIS, to retrieve Ice Water Path (IWP) values for several cases. Retrieved values are consistent with measurements reported by other researchers. Due to relatively large model and MODIS data uncertainties, particle size distribution properties were unable to be retrieved using this method. Previously reported MODIS calibration issues were found to limit the applicability of this method to other MODIS channels. The Eddington single-scattering hybrid model was found to accurately model these clouds. An extensive sensitivity study of this model was performed, resulting in the conclusion that colour-magnitude diagrams are too sensitive to uncertain factors to be used for cloud property retrieval.