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

Abstract

Abstract. The sensitivities of oxygen-dimer (O 4 ) 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.

An exploratory study on the aerosol height retrieval from OMI measurements of the 477 nm O<sub>2</sub> − O<sub>2</sub> spectral band using a neural network approach

“…Overall all the estimated NN retrieval uncertainties are in line with the theoretical sensitivity analyses of Park et al (2016), who found that the O 2 −O 2 at 477 nm is significantly influenced by aerosol optical properties (including ω 0 ), τ , particle size and A. In particular, a ω 0 uncertainty of 10 % was demonstrated to lead to the aerosol effective height (AEH) retrieval error ranging from 270 to 1440 m, depending on the aerosol types.…”

“…The low sensitivity to retrieve ALP when particles are located at a very high altitude is directly due to the O 2 −O 2 complex and its vertical distribution. This was demonstrated by Park et al (2016): O 2 −O 2 concentration exponentially decreases with increasing atmospheric altitude.…”

“…Park et al (2016) applied a lookup table (LUT) approach on this band to retrieve aerosol effective height over ocean, close to East Asia, within the error range of 1 km (compared to CALIOP). This approach was applied to seven case studies, each of them covering a few days.…”

“…Improvements may be obtained from a better knowledge of the surface albedo and higher accuracy of the aerosol model. Following the previous work over ocean of Park et al (2016), our study shows the first encouraging aerosol layer height retrieval results over land from satellite observations of the 477 nm O 2 −O 2 absorption spectral band. …”

“…The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) has been providing vertical profiles of aerosols but with limited spatial coverage because of its measurements characteristics (Omar et al, 2009). Park et al (2016) evaluated the sensitivity of the O 2 −O 2 slant column density to changes in aerosol layer height (ALH) over ocean. It is demonstrated that the O 2 −O 2 spectral band at 477 nm is the most sensitive to the aerosol layer effective height (compared to the O 2 −O 2 absorption bands at 340, 360 and 380 nm) due to the largest O 2 −O 2 absorption and reduced Rayleigh scattering.…”