title: Analysis of fine-mode aerosol retrieval capabilities by different passive remote sensing instrument designs.
abstract: Remote sensing of aerosol optical properties is difficult, but multi-angle, multi-spectral, polarimetric instruments have the potential to retrieve sufficient information about aerosols that they can be used to improve global climate models. However, the complexity of these instruments means that it is difficult to intuitively understand the relationship between instrument design and retrieval success. We apply a Bayesian statistical technique that relates instrument characteristics to the information contained in an observation. Using realistic simulations of fine size mode dominated spherical aerosols, we investigate three instrument designs. Two of these represent instruments currently in orbit: the Multiangle Imaging SpectroRadiometer (MISR) and the POLarization and Directionality of the Earths Reflectances (POLDER). The third is the Aerosol Polarimetry Sensor (APS), which failed to reach orbit during recent launch, but represents a viable design for future instruments. The results show fundamental differences between the three, and offer suggestions for future instrument design and the optimal retrieval strategy for current instruments. Generally, our results agree with previous validation efforts of POLDER and airborne prototypes of APS, but show that the MISR aerosol optical thickness uncertainty characterization is possibly underestimated.
authors.affiliation: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, New York 10025, USA. kirk.knobelspiesse@nasa.gov
authors.forename: Kirk
authors.initials: K
authors.lastname: Knobelspiesse
authors.forename: Brian
authors.initials: B
authors.lastname: Cairns
authors.forename: Michael
authors.initials: M
authors.lastname: Mishchenko
authors.forename: Jacek
authors.initials: J
authors.lastname: Chowdhary
authors.forename: Kostas
authors.initials: K
authors.lastname: Tsigaridis
authors.forename: Bastiaan
authors.initials: B
authors.lastname: van Diedenhoven
authors.forename: William
authors.initials: W
authors.lastname: Martin
authors.forename: Matteo
authors.initials: M
authors.lastname: Ottaviani
authors.forename: Mikhail
authors.initials: M
authors.lastname: Alexandrov