Utilization of O<sub>4</sub> slant column density to derive aerosol layer height from a space-borne UV–visible hyperspectral sensor: sensitivity and case study
The sensitivities of oxygen-dimer (O<sub>4</sub>) slant column densities (SCDs) to changes in aerosol layer height are investigated using the simulated radiances by a radiative transfer model, the linearized pseudo-spherical vector discrete ordinate radiative transfer (VLIDORT), and t...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-02-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/1987/2016/acp-16-1987-2016.pdf |
| Summary: | The sensitivities of oxygen-dimer (O<sub>4</sub>) slant column densities (SCDs) to
changes in aerosol layer height are investigated using the simulated
radiances by a radiative transfer model, the linearized pseudo-spherical
vector discrete ordinate radiative transfer (VLIDORT), and the differential
optical absorption spectroscopy (DOAS) technique. The sensitivities of the
O4 index (O4I), which is defined
as dividing O<sub>4</sub> SCD by 10<sup>40</sup> molecules<sup>2</sup> cm<sup>−5</sup>, to aerosol types and optical properties are also
evaluated and compared. Among the O<sub>4</sub> absorption bands at 340, 360, 380,
and 477 nm, the O<sub>4</sub> absorption band at 477 nm is found to be the most
suitable to retrieve the aerosol effective height. However, the O4I at 477 nm is significantly influenced not only by the aerosol layer effective
height but also by aerosol vertical profiles, optical properties including
single scattering albedo (SSA), aerosol optical depth (AOD), particle size,
and surface albedo. Overall, the error of the retrieved aerosol effective
height is estimated to be 1276, 846, and 739 m for dust, non-absorbing, and
absorbing aerosol, respectively, assuming knowledge on the aerosol vertical
distribution shape. Using radiance data from the Ozone Monitoring Instrument
(OMI), a new algorithm is developed to derive the aerosol effective height
over East Asia after the determination of the aerosol type and AOD from the
MODerate resolution Imaging Spectroradiometer (MODIS). About 80 % of
retrieved aerosol effective heights are within the error range of 1 km
compared to those obtained from the Cloud-Aerosol Lidar with Orthogonal
Polarization (CALIOP) measurements on thick aerosol layer cases. |
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| ISSN: | 1680-7316 1680-7324 |