Intercomparison of tropospheric ozone measurements from TES and OMI – a new method using a chemical transport model as comparison platform Lin Zhang, Daniel Jacob, Xiong Liu, Jennifer Logan, and the TES Science Team Aura Science Team Meeting (Oct. 28, 2008) Work supported by NASA Earth and Space Science Fellowship
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Lin Zhang, Daniel Jacob, Xiong Liu, Jennifer Logan, and the TES Science Team
Intercomparison of tropospheric ozone measurements from TES and OMI – a new method using a chemical transport model as comparison platform. Lin Zhang, Daniel Jacob, Xiong Liu, Jennifer Logan, and the TES Science Team. Aura Science Team Meeting (Oct. 28, 2008). - PowerPoint PPT Presentation
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Intercomparison of tropospheric ozone measurements from TES and OMI –
a new method using a chemical transport model as comparison platform
Lin Zhang, Daniel Jacob, Xiong Liu, Jennifer Logan, and the TES Science Team
Aura Science Team Meeting(Oct. 28, 2008)
Work supported by NASA Earth and Space Science Fellowship
Concurrent ozone measurements from IR and UV
OMI
Nadir-looking instrument measuring backscattered solar radiation (270-500 nm)
Daily global coverage at a spatial resolution of 13 x 24 km2 at nadir
Retrieve ozone at 24 ~2.5 km layers
Do they provide consistent measurements of tropospheric ozone?
What can we learn by comparing both measurements with chemical transport models?
TES
Infrared-imaging Fourier transform spectrometer (3.3-15.4 µm) 16 orbits of nadir vertical profiles at a spatial resolution of 5x8 km2 and spaced
1.6° along the orbit track every other day. Retrievals of ozone and CO at 67 levels from surface up to 0.1 hPa, version 3
data
Vertical sensitivity of TES and OMI ozone retrievals
July 2006 Degrees of Freedom for tropospheric ozone
Zonal average of Diagonal terms of AK
Averaging kernel
Both retrievals are obtained from the optimal estimation method [Rodgers, 2000]:
OMITES
Tropospheric ozone from TES and OMI
OMI observations are selected along TES pixels. The data are reprocessed with a single fixed a priori.
2006 ozone at 500 hPa averaged on 4ox5o resolution
Tropospheric ozone from TES, OMI and GEOS-Chem
The data and model results are reprocessed with a single fixed a priori. GEOS-Chem simulation in 4ox5o resolution is sampled along the TES/OMI pixels, and then smoothed by corresponding averaging kernels.
2006 ozone at 500 hPa averaged on 4ox5o resolution
Ozonesonde data from 2005-2007, available at AURA AVDC
1. Sonde method: Validation with ozonesonde measurements
Methods for the intercomparison
Sparse in time and space
Validation Validation
1. Sonde method: Validation with ozonesonde measurements
2. Direct method: Compare OMI/TES directly after considering their different a priori constrains and vertical sensitivity (Apply OMI averaging kernels to TES retrievals)
Direct comparison (Rodgers and Conner, 2003)
Methods for the intercomparison
Sparse in time and space
Validation Validation
1. Sonde method: Validation with ozonesonde measurements
2. Direct method: Compare OMI/TES directly after considering their different a priori constrains and vertical sensitivity (Apply OMI averaging kernels to TES retrievals)
3. CTM method: Use GEOS-Chem CTM as a comparison platform
Comparison Comparison
Comparison
Direct comparison (Rodgers and Conner, 2003)
Methods for the intercomparison
Sparse in time and space
Validation Validation
1. Sonde method: Validation with ozonesonde measurements
2. Direct method: Compare OMI/TES directly after considering their different a priori constrains and vertical sensitivity (Apply OMI averaging kernels to TES retrievals)
3. CTM method: Use GEOS-Chem CTM as a comparison platform