1. Remote sensing from POLDER/PARASOL Earth polar- orbiting satellite: enhanced Surface/Aerosol properties retrieval P. Litvinov, O. Dubovik, T. Lapyonok, F. Ducos, D. Tanre Laboratoire d'Optique Atmosphérique, CNRS, Universite Lille-1, FRANCE

2. Helsinki, August 19-21, 2013 Advanced retrieval algorithm Multi-spectral, multi-angle I, Q, U measurements Aerosol model Surface reflection model Enhanced retrieval of Aerosol/Surface properties AOD, Re(m), Im(m), Size distribution, fraction of spherical particles, surface parameters etc. Enhanced space-borne Aerosol/Surface retrieval

3. Reflection matrix for coupled atmosphere-surface system Helsinki, August 19-21, 2013 Aerosol and surface properties should be retrieved simultaneously!

4. independent POLDER/PARASOLindependent POLDER/PARASOL measurements : VIEWS: N 16: (80 0 180 0 ) INTENSITY (I): N t 6 (for aerosol): (0.44, 0.49, 0.56, 0.67, 0.865, 1.02 m) N t (for gas absorption): (0.763, 0.765, 0.910 m) POLARIZATION (Q, U): N P 3: (0.49, 0.67, 0.865 m) SINGLE OBSERVATION: N t N P ×N = (6+3)×16= 144 a lot !!! – as much as AERONET Helsinki, August 19-21, 2013

5. PARASOL daily coverage image, March 3, 2013 Helsinki, August 19-21, 2013 Swath: about 1600 km cross-track Global coverage: every 2 days 1 pixel spatial resolution: 5.3km × 6.2km

6. () 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). Helsinki, August 19-21, 2013

7. The concept of the GRASP 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) Bern, July 15-19, 2013

8. Aerosol model Helsinki, August 19-21, 2013 retrieved C + (1-C) Aerosol model is the same as in AERONET retrieval (Mixing of particle shapes (Dubovik et al., 2006))

9. Surface reflection model Helsinki, August 19-21, 2013 Semi-empirical models for surface total reflectance description: -RPV model (Rahman et al., (1993)) -Ross-Li (Ross, (1981); Li, X., Strahler (1992)) -Ross-Roujean model (Roujean et al., (1992)) Semi-empirical models for surface polarized reflectance description: -Nadal-Breon model (Nadal and Bréon, (1999)) -Maignan model (Maignan et al., (2009)) -Fresnel facet model for Gaussian surfaces (Litvinov et al., 2011) Physically based models for reflection matrix for surfaces: -Cox-Munk model (for aerosol retrieval over ocean) -Physical models for land surface reflection matrix (Litvinov et al., 2012)

10. Bern, July 15-19, 2013 10 Perfect retrieval of synthetic measurements!!!

11. Comparison with AERONET Bern, July 15-19, 201311 Banizoumbou Mongu Kanpur 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 Beiging

12. Bern, July 15-19, 2013 POLDER/AERONET. AOD. St.Dev.=0.160 St.Dev.=0.128

13. POLDER/AERONET. Angstrom Exponent. Bern, July 15-19, 2013 St.Dev.=0.262

14. POLDER/AERONET. SSA. Bern, July 15-19, 2013 St.Dev.=0.045 St.Dev.=0.051

15. Bern, July 15-19, 201315 DHR retrieval, Banizoumbou, 2007, 2008. Black curves and markers: DHR in 2007. Color curves and markers: DHR in 2008 There are possibilities for surface climatology and surface changes monitoring!!!

16. Surface modeling effect on aerosol retrieval. AOD retrieval over Banizoumbou, Mongu. Bern, July 15-19, 2013 16

17. Surface modeling effect on aerosol retrieval. SSA retrieval over Banizoumbou, Mongu Bern, July 15-19, 2013 17 Physical models are required to increase accuracy of aerosol retrieval.

18. I,Q,U retrieval vs I-retrieval: total reflectance fits Helsinki, August 19-21, 2013

19. I,Q,U retrieval vs I-retrieval: polarized reflectance fits Helsinki, August 19-21, 2013

20. I,Q,U retrieval vs I-retrieval retrieval: AOD (Banizoumbou) Helsinki, August 19-21, 2013 I,Q,U I-retrieval

21. I,Q,U retrieval vs I-retrieval retrieval: SSA (Banizoumbou) Helsinki, August 19-21, 2013 I,Q,U I-retrieval

22. Multi-pixel vs Single pixel retrieval: AOD (Banizoumbou) Helsinki, August 19-21, 2013 Multi-pixel Single pixel

23. Multi-pixel vs Single pixel retrieval: SSA (Banizoumbou) Helsinki, August 19-21, 2013 Multi-pixel Single pixel

24. Regional maps (1800 x 1800 km). Banizoumbou, AOD 670 nm Helsinki, August 19-21, 2013 Strong spatial and temporal variation of AOD

25. Regional maps (1800 x 1800 km). Banizoumbou, SSA 670 nm Helsinki, August 19-21, 2013 Essential temporal variation of SSA

26. Daily variation of AOD and SSA at 670 nm. Banizoumbou (Jan., Febr. 2008). Helsinki, August 19-21, 2013 21.02.2008 23.02.2008

27. Regional maps (1800 x 1800 km). Banizoumbou, SALB 670 nm Bern, July 15-19, 2013 Surface is very stable for Jan. and Febr.!

28. Regional maps (1800 x 1800 km). Mongu, SSA 670 nm Helsinki, August 19-21, 2013 Small SSA correspond to biomass burning NASA Global Fire Maps 28.08.2008 – 06.09.2008 (detected by MODIS)

29. Helsinki, August 19-21, 2013 Advanced retrieval Algorithm - LOA (Lille, France) GRASP algorithm (O.Dubovik et al, AMT, 2011). - SRON (Utrecht, The Netherlands) algorithm (O.Hasekamp et al, JGR, 2012) Multi-spectral, multi-angle I, Q, U measurements PARASOL will end up in September 2013. There may be 7 years gap in polarimetric space-borne measurements!!! Aerosol model At present time the mixture of spherical and spheroidal particles is the most comprehensive existent aerosol model (Dubovik et al., 2006). Surface reflection model - Physical models are required to increase accuracy of aerosol retrieval over land. - Physical models provide possibilities for surface characterization ( Litvinov et al., 2012). Enhanced retrieval of Aerosol/Surface properties Resume (space-borne Aerosol/Surface retrieval)

30. Helsinki, August 19-21, 2013 Multi-spectral, multi-angle I, Q, U space- borne measurements: - PARASOL will end up in September 2013! - 3MI will be launched in 2020 (?). - Ukrainian version of GISS NASA APS (Aerosol Polarimetry Sensor) instrument may be launched in 3 years (the possibility to set up Dutch SPEX instrument on the same satellite is being discussed now). There may be 7 years gap in polarimetric space-borne measurements!!! Advanced retrieval algorithm: - LOA (Lille, France) GRASP algorithm (O.Dubovik et al, AMT, 2011) - SRON (Utrecht, The Netherlands) algorithm (O.Hasekamp et al, JGR, 2012)

31. Helsinki, August 19-21, 2013 Aerosol model: At present time the mixture of spherical and spheroidal particles is the most comprehensive existent aerosol model (Dubovik et al., 2006). Surface reflection model - Physical models are required to increase accuracy of aerosol retrieval over land (Litvinov et al., 2011; Litvinov et al., 2012). - Physical models provide possibilities for surface characterization (Litvinov et al., 2012).