Improvements on geometry-dependent Lambertian-equivalent reflectivity (GLER) product by using MODIS MAIAC data over land
Abstract
We have developed the GLER (Geometry-dependent Lambertian-Equivalent Reflectivity) product from simulations of Rayleigh-only top-of-atmosphere (TOA) radiances assuming MODIS average surface BRDF and OMI (Ozone Monitoring Instrument) viewing geometry over the OMI field of view (FOV). GLER adequately accounts for surface BRDF effects while at the same time simplifies the surface BRDF implementation within the existing OMI retrieval infrastructure. Use of the GLER product requires changes only to the input surface reflectivity database but has improvement on NO2 and O2-O2 effective cloud fraction (ECF) retrievals, reducing cross-track dependence of retrieved ECF compared to that found when using the LER climatology.
The current version of GLER is based on the gap-filled Collection 5 (C5) MODIS BRDF/Albedo Product (MCD43GF) which has the shortest wavelength of 470 nm (band 3) for seasonal snow-free land surfaces. In this study, we use the Collection 6 (C6) Multi-Angle Implementation of Atmospheric Correction (MAIAC) data which has 412 (band 8) and 470 nm (band 3) as the two shortest wavelengths and provides pixel snow fraction that can be used for partial snow-cover scenes or seasonal snow/ice regions. We present the preliminary results comparing C5 vs C6 MCD43GF first, then with C6 MAIAC over typical geophysical regions. Special attention is paid to partial/full snow covered areas where MCD43GF has no data thus gap-filling with OMI measured reflectivity was applied in the first version. We discuss the GLER improvements and their effect on cloud and trace-gas retrievals for OMI and potentially for other satellite instruments (e.g., TROPOMI, TEMPO, and GOME-2).- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A13A..08Q
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0319 Cloud optics;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0360 Radiation: transmission and scattering;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 4275 Remote sensing and electromagnetic processes;
- OCEANOGRAPHY: GENERAL