A neural network approach to polarimetric observations of aerosols above
clouds - design, demonstration, and comparison to existing algorithms
Abstract
We present a neural network (NN) based algorithm for the retrieval of
cloud and aerosol properties from above cloud aerosol (ACA) scenes. The
large state space explored in ACA scenes causes traditional retrieval
approaches slow and complicated. This is especially true for optimal
inversion retrieval approaches, where a growth in the number of
dependent variables can drastically complicate and slow the retrieval
search. Our NN retrieval is applied to data from the airborne Research
Scanning Polarimeter (RSP), which measures both polarized and total
reflectance in the spectral range of 410 to 2260 nm, scanning along the
flight track at ~150 viewing zenith angles spanning the
angular range between -60˚ to 60˚. We apply this algorithm to field
campaign data from the ObseRvations of Aerosols above CLouds and their
intEractionS (ORACLES) 2016 and 2017 campaigns and compare to results
obtained from other algorithms.