Explicit and consistent aerosol correction for visible wavelength satellite cloud and nitrogen dioxide retrievals based on optical properties from a global aerosol analysis
<p>We discuss an explicit and consistent aerosol correction for cloud and <span class="inline-formula">NO<sub>2</sub></span> retrievals that are based on the mixed Lambertian-equivalent reflectivity (MLER) concept. We apply the approach to data from the Ozone...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-04-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/14/2857/2021/amt-14-2857-2021.pdf |
| Summary: | <p>We discuss an explicit and consistent aerosol correction for cloud and <span class="inline-formula">NO<sub>2</sub></span> retrievals that are based on the mixed Lambertian-equivalent reflectivity (MLER) concept. We apply the approach to data from the Ozone Monitoring Instrument (OMI) for a case study over northeastern China. The cloud algorithm reports an effective cloud pressure, also known as cloud optical centroid pressure (OCP), from oxygen dimer (<span class="inline-formula">O<sub>2</sub>−O<sub>2</sub></span>) absorption at 477 nm after determining an effective cloud fraction (ECF) at 466 nm. The retrieved cloud products are then used as inputs to the standard OMI <span class="inline-formula">NO<sub>2</sub></span> algorithm. A geometry-dependent Lambertian-equivalent reflectivity (GLER), which is a proxy of surface bidirectional reflectance, is used for the ground reflectivity in our implementation of the MLER approach. The current standard OMI cloud and <span class="inline-formula">NO<sub>2</sub></span> algorithms implicitly account for aerosols by treating them as nonabsorbing particulate scatters within the cloud retrieval. To explicitly account for aerosol effects, we use a model of aerosol optical properties from a global aerosol assimilation system and radiative transfer computations. This approach allows us to account for aerosols within the OMI cloud and <span class="inline-formula">NO<sub>2</sub></span> algorithms with relatively small changes. We compare the OMI cloud and <span class="inline-formula">NO<sub>2</sub></span> retrievals with implicit and explicit aerosol corrections over our study area.</p> |
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| ISSN: | 1867-1381 1867-8548 |