View‐angle consistency in reflectance, optical thickness and spherical albedo of marine water‐clouds over the northeastern Pacific through MISR‐MODIS fusion

Abstract

View‐angle consistency in bidirectional reflectance factor (BRF), optical thickness and spherical albedo is examined for marine water clouds over a region of the northeastern Pacific using six years of fused Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging SpectroRadiometer (MISR) data. Consistency is quantified by the root‐mean‐square of relative differences between MISR‐measured BRF and their plane‐parallel values and variation of plane‐parallel retrieved optical thickness and spherical albedo across multiple view‐angles. Probability distribution functions of consistency show that, for example, these clouds are angularly consistent within 5% in BRF, optical thickness and spherical albedo 72.2%, 39.0% and 81.1% of the time, respectively. We relate angular consistency to the spatial variability of nadir‐BRF, thus allowing us to potentially identify, with a prescribed confidence level, which MODIS microphysical retrievals within the MISR swath meet the plane‐parallel assumption to within any desired range in view‐angle consistency.