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P. Litvinov , O. Dubovik , T. Lapyonok , F. Ducos , D. Tanre

CCI option "POLDER over land upgrade algorithm (GRASP)": regional maps of aerosol/surface parameters and comparison with AERONET. P. Litvinov , O. Dubovik , T. Lapyonok , F. Ducos , D. Tanre. New POLDER/PARASOL algorithm (GRASP) ( Dubovik et al, AMT, 2011 ).

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P. Litvinov , O. Dubovik , T. Lapyonok , F. Ducos , D. Tanre

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  1. CCI option "POLDER over land upgrade algorithm (GRASP)": regional maps of aerosol/surface parameters and comparison with AERONET P. Litvinov, O. Dubovik, T. Lapyonok, F. Ducos, D. Tanre

  2. New POLDER/PARASOL algorithm(GRASP)(Dubovik et al, AMT, 2011) • The new algorithm uses complete set of PARASOL angular measurements in all spectral bands including both radiance and linear polarization measurements. • Continuous space of aerosol and surface properties is used. • The algorithm is based on statistically optimized fitting. The core of the new PARASOL algorithm is based on the same concept as AERONET aerosol retrieval (O. Dubovik and M. King, 2000; O. Dubovik, 2004; O. Dubovik et al, 2006). Frascati March 12, 2013

  3. Aerosol model Aerosol model is the same as in AERONET retrieval (Mixing of particle shapes (Dubovik et al., 2006)) retrieved C  + (1-C)  Aspect ratio distr. Frascati March 12, 2013

  4. Surface reflection model • Semi-empirical BRDF models (for surface total reflectance description): • RPV model (Rahman et al., (1993)) • Ross-Li (Ross, (1981); Li, X., Strahler (1992)) • Ross-Roujean model (Roujeanet al., (1992)) • Semi-empirical BPDF models (for surface polarized reflectance description): • Nadal-Breon model (Nadal and Bréon, (1999)) • Maignan model (Maignan et al., (2009)) • Physically based models for the reflection matrix for surfaces: • Cox-Munk model, Koepke model for whitecaps (for aerosol retrieval over ocean) • Physical models for land surface reflection matrix (Litvinov et al., 2011) Frascati March 12, 2013

  5. The concept of the algorithm Two scenarios of retrieval (Dubovik et al., AMT, 2011): • Conventional: single-pixel retrieval (each single pixel is inverted independently) • New concept: multiple-pixel retrieval (group of pixels are inverted simultaneously) Frascati March 12, 2013

  6. Regional maps (1800 x 1800 km).Banizoumbou, AOD 670 nm Strong spatial and temporal variation of AOD Frascati March 12, 2013

  7. Regional maps (1800 x 1800 km).Banizoumbou, SSA 670 nm Essential temporal variation of SSA Frascati March 12, 2013

  8. Daily variation of AODand SSA at 670 nm. Banizoumbou (Jan., Febr. 2008). 21.02.2008 23.02.2008 Frascati March 12, 2013

  9. Regional maps (1800 x 1800 km).Banizoumbou, SALB 670 nm Surface is very stable for Jan. and Febr.! Frascati March 12, 2013

  10. Regional maps (1800 x 1800 km).Beijing, AOD 670 nm Strong spatial and temporal variation of AOD Frascati March 12, 2013

  11. Regional maps (1800 x 1800 km).Beijing, SSA 670 nm Strong spatial and temporal variation of SSA Frascati March 12, 2013

  12. Daily variation of AODand SSA at 670 nm. Beijing (December, 2008). 01.12.2008 Small Values of AOD !!! 08.12.2008 Frascati March 12, 2013

  13. Regional maps (1800 x 1800 km).Beijing, SALB 670 nm Surface is stable for December! Frascati March 12, 2013

  14. Regional maps (1800 x 1800 km).Europe, AOD and SSA 670 nm Strong spatial variation of AOD and SSA Frascati March 12, 2013

  15. Regional maps (1800 x 1800 km).Europe, SALB 670 nm and 865 Big contrast between 670 and 865 because of vegetation!!! Frascati March 12, 2013

  16. Comparison with AERONET Beiging Kanpur Banizoumbou Mongu Banizoumbou: January, February, 2008 Surface: Grassland. Aerosol: Coarse mode is dominated. Mongu:August, September, 2008 Surface: Savanna. Aerosol: Fine mode is dominated. Beijing:April, December, 2008 Surface: Urban. Aerosol: Fine and Coarse modes. Kanpur:October-December, 2008 Surface: Urban. Aerosol: Fine and Coarse modes. The IGBP (International Geosphere Biosphere Programme) land type specification was used Frascati March 12, 2013

  17. AOD. POLDER/AERONET Frascati March 12, 2013

  18. Angstrom Exponent.POLDER/AERONET Frascati March 12, 2013

  19. SSA. POLDER/AERONET Frascati March 12, 2013

  20. Main issues to be solved • Acceleration of the inversion (Parallel GPU computation. First version of the parallelized code should be ready by the end of 2013). • Framework for PARASOL data preparation for the inversion with new algorithm (should be done by the end of 2013). Frascati March 12, 2013

  21. Next steps of LOA contribution into CCI project • Reprocessing 1 year (2008?) of PARASOL data with new algorithm (land + ocean) and validation/comparison with AERONET/MODIS. • Provide PARASOL Climatology (complex refractive index, size distribution, fraction of spherical particles, surface BRDF/BPDF parameters). Frascati March 12, 2013

  22. 300 by 300 pixels area projections Frascati March 12, 2013

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