remote sensing from polder/parasol earth polar- orbiting satellite: enhanced surface/aerosol...
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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
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
Reflection matrix for coupled atmosphere-surface system
Helsinki, August 19-21, 2013
I 0v
v 0
0
exp , expcos cosaer mol aer mol
v
t t
Aerosol and surface properties should be retrieved simultaneously!
0 0cos
““independentindependent”” POLDER/PARASOL POLDER/PARASOL
measurements :measurements :
VIEWS: N 16: (800 ≤ ≤ 1800)
INTENSITY (I): Nt6 (for aerosol): (0.44, 0.49, 0.56, 0.67, 0.865, 1.02 m)
Nt (for gas absorption): (0.763, 0.765, 0.910 m)
POLARIZATION (Q, U): NP3: (0.49, 0.67, 0.865 m)
SINGLE OBSERVATION:
NtNP
×N= (6+3)×16= 144
a lot !!! – as much as AERONET
Helsinki, August 19-21, 2013
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
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
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
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))
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)
Bern, July 15-19, 2013 10
Perfect retrieval of synthetic measurements!!!
Comparison with AERONET
Bern, July 15-19, 2013 11
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
Bern, July 15-19, 2013
POLDER/AERONET. AOD.
St.Dev.=0.160St.Dev.=0.128
POLDER/AERONET.Angstrom Exponent.
Bern, July 15-19, 2013
St.Dev.=0.262
POLDER/AERONET. SSA.
Bern, July 15-19, 2013
St.Dev.=0.045
St.Dev.=0.051
Bern, July 15-19, 2013 15
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!!!
Surface modeling effect on aerosol retrieval.AOD retrieval over Banizoumbou, Mongu.
Bern, July 15-19, 2013 16
Surface modeling effect on aerosol retrieval.SSA retrieval over Banizoumbou, Mongu
Bern, July 15-19, 2013 17Physical models are required to increase accuracy of aerosol retrieval.
I,Q,U retrieval vs I-retrieval: total reflectance fits
Helsinki, August 19-21, 2013
I,Q,U retrieval vs I-retrieval: polarized reflectance fits
Helsinki, August 19-21, 2013
I,Q,U retrieval vs I-retrieval retrieval: AOD (Banizoumbou)
Helsinki, August 19-21, 2013
I,Q,UI-retrieval
I,Q,U retrieval vs I-retrieval retrieval: SSA (Banizoumbou)
Helsinki, August 19-21, 2013
I,Q,UI-retrieval
Multi-pixel vs Single pixel retrieval: AOD (Banizoumbou)
Helsinki, August 19-21, 2013
Multi-pixel Single pixel
Multi-pixel vs Single pixel retrieval: SSA (Banizoumbou)
Helsinki, August 19-21, 2013
Multi-pixel Single pixel
Regional maps (1800 x 1800 km).Banizoumbou, AOD 670 nm
Helsinki, August 19-21, 2013
Strong spatial and temporal variation of AOD
Regional maps (1800 x 1800 km).Banizoumbou, SSA 670 nm
Helsinki, August 19-21, 2013
Essential temporal variation of SSA
Daily variation of AOD and SSA at 670 nm. Banizoumbou (Jan., Febr. 2008).
Helsinki, August 19-21, 2013
21.02.2008
23.02.2008
Regional maps (1800 x 1800 km).Banizoumbou, SALB 670 nm
Bern, July 15-19, 2013 Surface is very stable for Jan. and Febr.!
Regional maps (1800 x 1800 km).Mongu, SSA 670 nm
Helsinki, August 19-21, 2013
Small SSA correspond to biomass burning
NASA Global Fire Maps28.08.2008 – 06.09.2008
(detected by MODIS)
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
measurementsPARASOL will end up in September 2013. There may be 7 years gap in polarimetric space-borne measurements!!!
Aerosol modelAt 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)
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)
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).
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