TEMPO Simulation and Retrieval Tools and Algorithm Testing at SAO

Xiong Liu

xliu@cfa.harvard.edu

3rd TEMPO Science Team Meeting

Huntsville, Al, May 27, 2015

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TEMPO Retrieval Sensitivity Studies

• Performed RTM simulations of TEMPO radiance spectra and retrieval sensitivity studies for determining instrument requirements and verifying instrument performance. VLIDORT: adapted from previous GEO-CAPE tools, with interfaces for

viewing geometry, built-in cross sections, pre- and after- convolution, HITRAN line by line calculations, aerosol profiles and plumes, scattering clouds, IPA, Koelemeijer GOME surface albedo database or input surface reflectance spectra

Hourly fields of GEOS-Chem model fields over TEMPO field of regard for 12 days (1 day/month) up to SZA 80° ~90000 simulations with 10 gases (O3, NO2, H2CO, SO2, C2H2O2, H2O), BrO, OClO, O2, O4

, 6 types of aerosols, water/ice clouds

TEMPO SNR model: account for optical transmission and grating efficiency, including shot, dark current, RTN, readout, quantization, smear, CTE noise terms

Climatological a priori: climatological for O3, unconstrained for other trace gas VCDs, consistent with current algorithms

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TEMPO Retrieval Sensitivity Studies

• Continue: Optimal estimation based retrieval sensitivity tool (IDL-based)

Calculate retrieval averaging kernels, estimate retrieval errors for both O3 profile and other trace gas VCDs and perform error analysis (e.g., radiance errors, polarization sensitivity, forward model parameters) for determining retrieval error budgets and calibration requirements

To be added: BRDF, EOFs of surface reflectance spectra with high-resolution MODIS BRDF climatology

To be added: Rotational-Raman scattering (look-up table)

2 2

2

2 2

{ ( - ) -[ ( )]} ( - ) a

1 1- -2 2y i i+1 i i i+1 aS K X X Y -R X S X X

( )retS a

T -1 -1 -1i y iK S K S

Same as NLLS for VCDs (unconstrained)

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Algorithm testing

• Fully test L0-L2 algorithms using synthetic data: Hourly high spatial resolution data (e.g., GEOS-5 nature run at 7×7 km2 from

A. Silva): 1 day/month RTM simulations Radiance spectrum L1 data L0 data Test L0 L1 and L1L2 algorithms