ASI STUDY CONTRACT REPORT - ASI CONTRACT N° 2019-20-HH.0 - Project Name: FORUM SCIENZA

The FORUM SCIENZA project was one of the main initiatives in Italy that made it possible to bring together the entire national community that has been working on the ESA Earth Explorer 9th FORUM mission, proposed to ESA by CNR-INO in 2017. The project, which involves the CNR, the University of Basilicata, and the University of Bologna, started in 2019 and finished at the end of 2022. The main objective of the project is to coordinate the national community around the exploitation of the far infrared spectral measurement of the Earth longwave radiation, which represents the observational gag that will be covered by the FORUM mission. This was pursued by developing both a flexible numerical analysis code based on national routines and a prototype for field measurements that will be used for the preparation of the FORUM mission and the future exploitation of the measurements that will be delivered by the satellite, once in orbit. A numerical tool was developed for the radiative transfer simulation and the inversion of the FORUM measurements. The tool, named ?-FORUM, includes a fast radiative transfer algorithm, called ?-FORUM, and a retrieval algorithm, called ?-FORUM. The codes were developed using the optical depth calculated with the Italian KLIMA code for clear sky and the databases of optical properties for cloudy conditions. ?- FORUM was validated against standard models, typically used at international level, such as LBLRTM and the national GBB. On the experimental side, the project allowed to improve the FIRMOS ground-based prototype, available at CNR-INO, and to adapt its relevant subsystems to stratospheric balloon-borne flights. The instrument was installed on the CNES CARMEN and performed a first flight from Timmins (CAN) in August 2022. Finally, during the project, different actions was taken in order to strengthen the cooperation between the Italian teams both with national and international initiatives. Among them, the "CAMEO - Climate And Meteorology, modeling and Earth Observations" workshop, organised virtually in January 2022, brought together around 100 Italian participants including climatologists, meteorologists and researchers interested in the development of the FORUM topics.