Abstract
Abstract. The theoretical basis of the Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP) Version 1 aerosol extinction retrieval algorithm is presented. The algorithm uses an assumed bimodal lognormal aerosol size distribution to retrieve aerosol extinction profiles at 675 nm from OMPS LP radiance measurements. A first-guess aerosol extinction profile is updated by iteration using the Chahine nonlinear relaxation method, based on comparisons between the measured radiance profile at 675 nm and the radiance profile calculated by the Gauss–Seidel limb-scattering (GSLS) radiative transfer model for a spherical-shell atmosphere. This algorithm is discussed in the context of previous limb-scattering aerosol extinction retrieval algorithms, and the most significant error sources are enumerated. The retrieval algorithm is limited primarily by uncertainty about the aerosol phase function. Horizontal variations in aerosol extinction, which violate the spherical-shell atmosphere assumed in the version 1 algorithm, may also limit the quality of the retrieved aerosol extinction profiles significantly.
Highlights
Most of the aerosols found in the Earth’s atmosphere occur in the planetary boundary layer, due to the wide variety of aerosol sources that exist at the surface
For the Version 1 (V1) Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP) βa retrieval algorithm, we introduce the added complexity of the bimodal LN Aerosol size distribution (ASD) because it generally describes the properties of stratospheric aerosol observations better (Thomason and Peter, 2006)
The 675 nm radiances used in the V1 OMPS LP βa retrieval algorithm lie within the Chappuis ozone absorption band, and the βa estimate is influenced by possible differences between the true ozone profile and the ozone profile that is assumed in the calculation of yin in Eq (3)
Summary
Most of the aerosols found in the Earth’s atmosphere occur in the planetary boundary layer, due to the wide variety of aerosol sources that exist at the surface (dust, smoke, sea salt, etc.). Several competing influences affect the stratospheric aerosol layer, including volcanic activity, stratosphere–troposphere exchange, stratospheric transport processes, gas-to-droplet conversion rates, and particle sedimentation. R. Loughman et al.: OMPS LP V1 aerosol extinction retrieval algorithm: theoretical basis which increases the planetary albedo and cools the troposphere (Robock, 2000; Kravitz et al, 2011; Ridley et al, 2014). Loughman et al.: OMPS LP V1 aerosol extinction retrieval algorithm: theoretical basis which increases the planetary albedo and cools the troposphere (Robock, 2000; Kravitz et al, 2011; Ridley et al, 2014) The magnitude of this effect varies significantly with latitude, solar zenith angle, etc. A recent review of the observations and processes of stratospheric aerosol and how they impact the Earth’s climate is presented in (Kremser et al, 2016)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
