Title :

Retrieving aerosol characteristics from the pace mission, part 2: multi-angle and polarimetry

Author(s) :

Remer, Lorraine [Auteur]
Knobelspiesse, Kirk [Auteur]
Zhai, Peng-Wang [Auteur]
Xu, Feng [Auteur]
Kalashnikova, Olga [Auteur]
Chowdhary, Jacek [Auteur]
Hasekamp, Otto [Auteur]
Doubovik, Oleg [Auteur]
Laboratoire d’Optique Atmosphérique - UMR 8518 [LOA]
Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518
Wu, Lianghai [Auteur]
Ahmad, Ziauddin [Auteur]
Boss, Emmanuel [Auteur]
Cairns, Brian [Auteur]
Coddington, Odele [Auteur]
Davis, Anthony B. [Auteur]
Dierssen, Heidi M. [Auteur]
Diner, David J. [Auteur]
Franz, Bryan [Auteur]
Frouin, Robert [Auteur]
Gao, Bo-Cai [Auteur]
Ibrahim, Amir [Auteur]
Levy, Robert [Auteur]
Martins, Vanderlei [Auteur]
Omar, Ali [Auteur]
Torres, Omar [Auteur]

Journal title :

Frontiers in Environmental Science

Abbreviated title :

Front. Environ. Sci.

Volume number :

7

Publication date :

2019-07-23

ISSN :

2296-665X

English keyword(s) :

aerosol
multi-angle
polarimeter
PACE
remote sensing
multi-wavelength

HAL domain(s) :

Physique [physics]

English abstract : [en]

The Plankton, Aerosol, Clouds, ocean Ecosystem (PACE) mission presents new opportunities and new challenges in applying observations of two complementary multi-angle polarimeters for the space-based retrieval of global ...
Show more >The Plankton, Aerosol, Clouds, ocean Ecosystem (PACE) mission presents new opportunities and new challenges in applying observations of two complementary multi-angle polarimeters for the space-based retrieval of global aerosol properties. Aerosol remote sensing from multi-angle radiometric-only observations enables aerosol characterization to a greater degree than single-view radiometers, as demonstrated by nearly two decades of heritage instruments. Adding polarimetry to the multi-angle observations allows for the retrieval of aerosol optical depth, Angstrom exponent, parameters of size distribution, measures of aerosol absorption, complex refractive index and degree of non-sphericity of the particles, as demonstrated by two independent retrieval algorithms applied to the heritage POLarization and Directionality of the Earth's Reflectance (POLDER) instrument. The reason why this detailed particle characterization is possible is because a multi-angle polarimeter measurement contains twice the number of Degrees of Freedom of Signal (DFS) compared to an observation from a single-view radiometer. The challenges of making use of this information content involve separating surface signal from atmospheric signal, especially when the surface is optically complex and especially in the ultraviolet portion of the spectrum where we show the necessity of polarization in making that separation. The path forward is likely to involve joint retrievals that will simultaneously retrieve aerosol and surface properties, although advances will be required in radiative transfer modeling and in representing optically complex constituents in those models. Another challenge is in having the processing capability that can keep pace with the output of these instruments in an operational environment. Yet, preliminary algorithms applied to airborne multi-angle polarimeter observations offer encouraging results that demonstrate the advantages of these instruments to retrieve aerosol layer height, particle single scattering albedo, size distribution and spectral optical depth, and also show the necessity of polarization measurements, not just multi-angle radiometric measurements, to achieve these results.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Collections :

• Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518

Submission date :

2024-01-30T11:45:54Z
2024-02-26T13:59:09Z