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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
K.-U. Eichmann, C. von Savigny, G. Rohen, J. Kaiser, H. Bovensmann, J.P. Burrows
First retrieval of NIR CH4 profiles from SCIAMACHY measurements?
Institute of Environmental PhysicsUniversity of Bremen
Germany
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
• vertical resolution: 2.6 km• horizontal resolution in
azimuth direction: 240 km (120 km min.)
• horizontal resolution in flight direction: approx. 400 km
• Duration of Limb sequence: 60 sec.
SCIAMACHY Limb Measurements
Limb view for SOLSE/LORE instruments
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Requirements UV-VIS-SWIR RTM Limb
SCIATRAN/CDIPI
(A. Rozanov 2001)
SCIARAYs
(Kaiser 2001)
Refraction
Full Sphericity
Multiple Scattering (double scattering)
Ground Reflection
Rayleigh, Mie-Scattering
Analytical Weighting Functions
(In progress)
Computational fast for global analysis of data
Occultation included
Modelling the Radiative Transfer
SCIARAYS: LBL mode, SFC included
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Optimal Estimation
x0: ln of the a priori O3 profile xn: ln of the nth estimatey: ln of the measured Chappuis-Triplettsyn: ln of the modelled Chappuis-Tripletts for xn
Sx: covariance matrix of the a priori S: covariance matrix of yK: Weighting function matrix
n3
mcmn zOln
THlnyK
yn and K will be determined by the radiative transfer model SCIARAYS [Kaiser, 2001]
xn+1 = x0 + SxKnT[KnSxKn
T + S] -1 (y - yn - Kn(x0-xn))
S = Sx - SxKT[KSxKT + S]-1 KSx
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Rozanov: Differential retrieval employing O3 Huggins and Chappuis bandsSavigny: 3 wavelength retrieval employing O3 Chappuis bands
10
20
30
40
50
0 1x1012 2x1012 3x1012 4x1012 5x1012 6x1012 7x1012
10 - 40 km O3 columns:
SCIAMACHY: 378 DUPOAM III: 384 DU
Total O3 column:
GOME: 459 DUTOMS: 456 DU
SCIAMACHY - POAM III coincidence on April 25, 2002
SCIA, Rozanov Lat: 56o-59o N, Long: 238o-253o, 18:30 UTC
SCIA, Savigny Lat: 56o-59o N, Long: 238o-253o, 18:30 UTC
POAM, Lat: 62o N, Long: 253o, 2:50 UTC
O3 density [cm -3]
Altitu
de
[km
]
Is SCIARAYS good enough?
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
CH4 x-section
Ch. 6 (1000-1750 nm, 1.5 nm)
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
CH4 x-section channel 8
Ch. 8 (2265-2380 nm, 0.26 nm)
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Convoluted x-section of CH4
Hitran 2000 database
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
VMR profiles of NIR absorbers
Profiles from ACE study
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Radiance at 6 km Tangent height
CH4 (using SCIARAYS in LBL mode)
CH4 (after slit function convolution)
Red: H2OBlue: CO2
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Radiance without CO2 and H2O
Dotted Line: without CO2 and H2O
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
High resolution
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Modelled Radiances after SFCTangent heightsevery 3 km between3 and 30 km (from top to bottom), Using SCIARAYS as a RTM.
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Smoothed WF
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
WF @ 1666 nm
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Different THs @ Channel 6
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
SCIAMACHY Level 1 measurementsat 10 and 16 km
TH = 10 km(twilight measurements)
TH = 10 km(daytime measurements)
TH = 16 km(daytime)
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
SCIAMACHY Level 1 measurementsat 10 and 16 km
TH = 10 km(twilight measurements)
TH = 10 km(daytime measurements)
TH = 16 km(daytime)
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
SCIA L1: 20 and 26 km
With dead/bad pixels
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Without dead/bad pixel
20 km
26 km
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
SCIAMACHY Channel 6: TH=65.8 km
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
One state (Ch. 6) at 85 km
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Mesospheric OH emission lines
Black:Night
Red:Twilight
Blue:Day
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Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering
Conclusions
• NIR retrieval chain is not ready yet, but will be in the next few weeks.
• If it is possible to retrieve CH4 from Channel 6 (or Channel 8) from Limb measurements is still an open question.
• OH (both night and day emissions) seems to be a good candidate for further studies.