Barbosa,António Joaquim Rosa AmorimTomé,António RodriguesMendeiros,Pedro Miguel Ferreira2026-01-142026-01-142025http://hdl.handle.net/10400.5/116591Tese de Mestrado, Engenharia Física, 2025, Universidade de Lisboa, Faculdade de CiênciasThe CLOUD (Cosmics Leaving Outdoor Droplets) experiment at CERN addresses the largest source of uncertainty in global climate models: the effect of aerosols in cloud formation. This dissertation focused on optimizing data analysis routines on the CLOUD collaboration, aiming to reduce these climate uncertainties. The primary objective was twofold: to enhance the accuracy of the New Particle Formation rate calculation and to develop a robust predictive model for the rate of change of the key aerosol precursor, sulfuric acid. The methodological work involved the re-implementation and optimization of the Formation Rate calculation script in Python, which critically corrected a dimensional inconsistency in the coagulation sink term found in previous implementations, and incorporated advanced signal processing techniques for a more scientifically rigorous result. Furthermore, Machine Learning models were developed using CLOUD16 campaign data to predict the sulfuric acid concentration, incorporating key experimental parameters. After comparison, the non-linear XGBoost model was selected as the superior predictive tool, demonstrating a greater capacity to capture the complex, non-linear relationships driving sulfuric acid dynamics. In conclusion, this work provides a new, reliable analytical and predictive framework for the CLOUD collaboration, contributing directly to more precise data interpretation and supporting a deeper understanding of aerosol formation mechanisms.application/pdfengCloud FormationNew Particle FormationMachine LearningAerosolsmaster thesis204176204