Improving the retrieval of downwelling surface shortwave fluxes using data from geostationary satellites

Shortwave radiation is a key quantity to estimate the surface radiation budget which has a close relationship with the climate of a given region. Shortwave radiation is affected by aerosols and clouds. Aerosols modify the Earth’s radiation budget and boundary layer meteorology by reflecting sunlight to space and absorbing radiation in the atmosphere. Clouds modulate the vertical and horizontal distributions of solar radiative heating, latent heat, and cooling by thermal radiation that drive the atmospheric circulation. The main objective of this thesis is to analyze in detail the methodology presently used to derive the Downwelling Surface Shortwave Flux (DSSF) based on information from geostationary satellites. The study is closely related to operational activities developed within the framework of the Satellite Application Facility on Land Surface Analysis (LSA SAF). An already existing operational DSSF algorithm, developed within the framework of the Ocean and Sea Ice (O&SI) SAF, is tested and improved for clear and cloudy sky conditions. In the case of clear sky, the parameterisation for atmospheric absorption accounts for the variation of the concentration of the atmospheric components. In the case of cloudy sky, radiation interactions are more complex and, besides the interaction with the atmosphere, the parameterisation scheme accounts for cloud albedo and relies on a predefined value characterizing the absorption by clouds. Both methodologies are analyzed and two parameterizations are proposed; for cloudy sky pixels the new parameterisation takes cloud types into account whereas, in the clear sky case, diffuse radiation is explicitly included in the DSSF model, based on information about aerosol optical thickness. Model performance is significantly improved and for both methodologies an approach to their integration in an operational environment is proposed.A elaboração de cenários do clima futuro pressupõe um conhecimento sólido do estado do clima, quer do passado, quer do presente. O Sol é a fonte primária de energia do sistem climático, estando na origem das circulações oceânica e atmosférica que modulam as interacções entre a atmosfera e a hidrosfera, bem como entre estas e as restantes componentes do Sistema Climático, nomeadamente a criosfera, a litosfera e a biosfera. Os ciclos hidrológico e do carbono constituem exemplos de tais interacções e o seu conhecimento afigura-se crucial para que se possam antecipar possíveis comportamentos do clima no futuro. No contexto acima descrito, o conhecimento do balanço radiativo à superfície do solo é fundamental em inúmeras aplicações, tais como na previsão numérica do estado do tempo e na gestão de recursos naturais. Em particular, revela-se essencial possuir um conhecimento aprofundado das interacções da energia solar com a atmosfera e com a superficíe do solo a fim de que se possa dar resposta a um leque vasto de questões relacionadas com a evolução do clima actual. Assim é, por exemplo, que o facto de a absorção de pequeno comprimento de onda ter vindo a ser subestimada, seja em condições de céu limpo, seja de céu nublado, tem implicações profundas para o balanço energético nos modelos de circulação global. Nesta conformidade, uma maior precisão na estimativa da radiação de pequeno comprimento de onda deverá ter repercussões positivas na caracterização do clima e na elaboração de cenários do clima futuro.Fundação para a Ciência e a Tecnologi

HETEAC: The Aerosol Classification Model for EarthCARE

We introduce the Hybrid End-To-End Aerosol Classification (HETEAC) model for the upcoming EarthCARE mission. The model serves as the common baseline for development, evaluation, and implementation of EarthCARE algorithms. It shall ensure the consistency of different aerosol products from the multi-instrument platform as well as facilitate the conform specification of broad-band optical properties necessary for the EarthCARE radiative closure efforts. The hybrid approach ensures the theoretical description of aerosol microphysics consistent with the optical properties of various aerosol types known from observations. The end-to-end model permits the uniform representation of aerosol types in terms of microphysical, optical and radiative properties

A New Inversion Scheme for the RPV Model.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

ICAROHS - Inter-Comparison of Aerosol Retrievals and Observational Requirements for Multi-wavelength HSRL Systems

The ESA-STSE study ICAROHS exploits the potential improvements and benefits of novel multi-wavelength High Spectral Resolution Lidar (HSRL) technology combined with innovative retrieval methods for future satellite missions. Single-wavelength HSRL data from several field studies form the data base for developing improved scientific algorithms for retrievals of aerosol optical properties and of tools for future multi-wavelength spaceborne HSRL instrument assessments. These quality-controlled observational data feed into the existing EarthCARE simulator (ECSIM), which serves as the platform for algorithm development and verification. Light scattering by non-spherical particles is implemented into ECSIM as scattering libraries based on T-matrix calculations. Recommendations for future multi-wavelength HSRL missions are formulated on the basis of a combined retrieval of aerosol properties from the entire available lidar and in-situ data. This retrieval study forms the benchmark for aerosol properties accessible by respective HSRL missions and defines the technical limits for required accuracy and resolution of the lidar input data to the novel algorithms

The Impact of Multi-Angular Measurements on the Accuracy of Land-Surface Albedo Retrieval. Preliminary Results for the Proposed ESA LSPIM Mission.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

The Impact of Multi-Angular Measurements on the Albedo Retrieval Accuracy. Preliminary Results for the Proposed ESA LSPIM Mission

Abstract not availableJRC.(SAI)-Space Application Institut

HETEAC: The Aerosol Classification Model for EarthCARE

We introduce the Hybrid End-To-End Aerosol Classification (HETEAC) model for the upcoming EarthCARE mission. The model serves as the common baseline for development, evaluation, and implementation of EarthCARE algorithms. It shall ensure the consistency of different aerosol products from the multi-instrument platform as well as facilitate the conform specification of broad-band optical properties necessary for the EarthCARE radiative closure efforts. The hybrid approach ensures the theoretical description of aerosol microphysics consistent with the optical properties of various aerosol types known from observations. The end-to-end model permits the uniform representation of aerosol types in terms of microphysical, optical and radiative properties

HETEAC: The Aerosol Classification Model for EarthCARE

We introduce the Hybrid End-To-End Aerosol Classification (HETEAC) model for the upcoming EarthCARE mission. The model serves as the common baseline for development, evaluation, and implementation of EarthCARE algorithms. It shall ensure the consistency of different aerosol products from the multi-instrument platform as well as facilitate the conform specification of broad-band optical properties necessary for the EarthCARE radiative closure efforts. The hybrid approach ensures the theoretical description of aerosol microphysics consistent with the optical properties of various aerosol types known from observations. The end-to-end model permits the uniform representation of aerosol types in terms of microphysical, optical and radiative properties

HETEAC: The Aerosol Classification model for EarthCARE

We introduce the Hybrid End-To-End Aerosol Classification (HETEAC) model for the upcoming EarthCARE mission. The model serves as the common baseline for development, evaluation, and implementation of EarthCARE algorithms. It shall ensure the consistency of different aerosol products from the multi-instrument platform as well as facilitate the conform specification of broad-band optical properties necessary for the EarthCARE radiative closure efforts. The hybrid approach ensures the theoretical description of aerosol microphysics consistent with the optical properties of various aerosol types known from observations. The end-to-end model permits the uniform representation of aerosol types in terms of microphysical, optical and radiative properties