A41L-07
Joint aerosol and water-leaving radiance retrieval from Airborne Multi-angle SpectroPolarimeter Imager

Thursday, 17 December 2015: 09:30
3002 (Moscone West)
Feng Xu1, Oleg Dubovik2, Pengwang Zhai3, Olga Kalashnikova4 and David J Diner4, (1)Jet Propulsion Laboratory, Pasadena, CA, United States, (2)University of Lille 1, Laboratoire d'Optique Atmosphérique, Villeneuve d'Ascq, France, (3)University of Maryland Baltimore County, Baltimore, MD, United States, (4)NASA Jet Propulsion Laboratory, Pasadena, CA, United States
Abstract:
The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) [1] has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. In step-and-stare operation mode, AirMSPI typically acquires observations of a target area at 9 view angles between ±67° off the nadir. Its spectral channels are centered at 355, 380, 445, 470*, 555, 660*, and 865* nm, where the asterisk denotes the polarimetric bands. In order to retrieve information from the AirMSPI observations, we developed a efficient and flexible retrieval code that can jointly retrieve aerosol and water leaving radiance simultaneously. The forward model employs a coupled Markov Chain (MC) [2] and adding/doubling [3] radiative transfer method which is fully linearized and integrated with a multi-patch retrieval algorithm to obtain aerosol and water leaving radiance/Chl-a information. Various constraints are imposed to improve convergence and retrieval stability. We tested the aerosol and water leaving radiance retrievals using the AirMSPI radiance and polarization measurements by comparing to the retrieved aerosol concentration, size distribution, water-leaving radiance, and chlorophyll concentration to the values reported by the USC SeaPRISM AERONET-OC site off the coast of Southern California. In addition, the MC-based retrievals of aerosol properties were compared with GRASP ([4-5]) retrievals for selected cases. The MC-based retrieval approach was then used to systematically explore the benefits of AirMSPI’s ultraviolet and polarimetric channels, the use of multiple view angles, and constraints provided by inclusion of bio-optical models of the water-leaving radiance.

References

[1]. D. J. Diner, et al. Atmos. Meas. Tech. 6, 1717 (2013).

[2]. F. Xu et al. Opt. Lett. 36, 2083 (2011).

[3]. J. E. Hansen and L.D. Travis. Space Sci. Rev. 16, 527 (1974).

[4]. O. Dubovik et al. Atmos. Meas. Tech., 4, 975 (2011).

[5]. O. Dubovik et al. SPIE: Newsroom, DOI:10.1117/2.1201408.005558 (2014).

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