CESOC kindly invites you to a talk given by Dr. Tiziano Maestri, from University of Bologna, Physics and Astronomy Department “Augusto Righi”, Bologna, Italy, with the title:
Far- and Mid-Infrared Radiances in All-Sky Conditions: Simulations and Real Data Inversion
Date: 02 December 2025
Time: 16:00 CEST
Location: University of Cologne
Please use the entrance at Höninger Weg 100, 50969 Cologne. Ring the bell labeled “Hörsaal Universität Köln – Öffnungszeit 7–18 Uhr” to enter; the door will open automatically. The session takes place in Lecture Hall 4.001 on the 4th floor.
For online participation, please contact info@cesoc.net
Abstract:
The role played by Far Infra-Red (FIR) radiation in shaping the Earth’s energy balance and its sensitivity to essential climate variables such as temperature, water vapor, surface emissivity, and clouds is well recognized by the scientific community. In this regard, the European Space Agency (ESA) selected the Far-infrared Outgoing Radiation Understanding and Monitoring (FORUM) mission as its ninth Earth Explorer, scheduled to launch in 2027. FORUM will measure the outgoing longwave radiation in the spectral range from 100 to 1600 cm−1, with 0.5 cm−1 (un-apodized) spectral resolution. On its side, NASA launched, in 2024, two CubeSats carrying the Polar Radiant Energy in the Far-InfraRed Experiment (PREFIRE) which are measuring the 0-54 𝜇m region at 0.84 𝜇m spectral resolution.
In this work we focus on clous studies and present the last progresses obtained on cloud identification, radiative modelling and properties retrieval using Mid Infra-Red and FIR channels.
First, we show the application of the Cloud Identification and Classification (CIC) algorithm [Maestri et al., 2019] to ground-based observations for the detection of Antarctic clouds. Cloud occurrence time series in the timeframe 2014–2020 are analysed and the cloud radiative effects are discussed. Ground-based cloud classifications are compared to satellite-derived products of the Infrared Atmospheric Sounding Interferometer (IASI) flying on MetOp A, B, and C.
Successively, we introduce a physical, fast and accurate rt code, sigma-FORUM, which relies on simplifications of the multiple scattering term. We focus on scaling methods operating at FIR and in presence of scattering layers (both clouds and aerosols) which can be adopted in inversion processes for the definition of satellite level 2 products or simply for the analysis of spectrally remotely sensed radiance fields. The work discusses the limits of the Chou approximation [Chou et al., 1999; Martinazzo et al., 2021] when applied to radiance simulations and provides a characterization of the impact of the Chou adjustment proposed by Tang et al. in 2018 for fluxes and implemented, in the sigma-FORUM forward model, using an innovative scheme for radiance computations [Masiello et al., 2024; Maestri et al., 2024]. To assess the algorithm performances, results obtained using sigma-FORUM are compared to those derived with a discrete-ordinate based radiative transfer model (DISORT) for a wide range of physical and optical properties of ice and liquid water clouds and for multiple atmospheric conditions. Additionally, we discuss the algorithm effectiveness in simulating a set of ECMWF analyses on a global scale. For this purpose, we compare the fast available solutions to observations of the IASI which are also used for the derivation of the clouds and atmospheric parameters using a new inversion code (iota-FORUM) based on sigma-FORUM.
Bio:
Tiziano Maestri is Associate Professor at the Physics and Astronomy Department “Augusto Righi” of the University of Bologna where he teaches in the master’s degrees of “Physics of Earth’s interior, Ocean and Atmosphere” and “Science of Climate”. The main part of the scientific activity is currently related to the European Space Agency satellite mission FORUM (The Far-infrared Outgoing Radiation Understanding and Monitoring) of which Tiziano Maestri is one of the proposers and developers. He is the PI of the ASI “FIT-FORUM” and of the ESA “FORUM E2E Simulator” projects. TM is also involved in the modelling of radiative transfer at limb in support of the CAIRT (Changing-Atmosphere InfraRed Tomography) ESA 11th Earth Explorer candidate Mission with 3 open projects: the ASI “CASIA-CAIRT”, and the ESA “CAIRTEX” and “PerREC” projects. He participates in national extended partnerships such as the “Space It Up” project funded by ASI and MUR and the “RETURN” project funded by the European Union Next-GenerationEU. TM leads the radiative transfer and remote sensing group at University of Bologna. He is elected member (2024-28) of the International Radiation Commission.