Publicação
From the added value of regional and convective climate simulations to a new insight into drought assessment
| dc.contributor.author | Careto, João António Martins | |
| dc.contributor.institution | Faculty of Sciences | |
| dc.contributor.supervisor | Soares, Pedro Miguel Matos | |
| dc.contributor.supervisor | Cardoso, Rita M. | |
| dc.date.accessioned | 2026-02-09T16:45:00Z | |
| dc.date.available | 2026-02-09T16:45:00Z | |
| dc.date.issued | 2025-07-08 | |
| dc.description | Tese de doutoramento em Ciências Geofísicas e da Geoinformação (Meteorologia), Universidade de Lisboa, Faculdade de Ciências, 2025. | |
| dc.description.abstract | As alterações climáticas, consequência da emissão de gases de efeito de estufa e das mudanças de uso-do-solo associadas às atividades humanas, impactam o ambiente e a sociedade. Estas alterações referem-se a mudanças na média e/ou extremos das variáveis climáticas ao longo do tempo. Por forma a avaliar o sistema climático, desenvolveram-se modelos climáticos globais e regionais (GCM e RCM). Exemplos importantes de esforços internacionais de modelação climática são, por exemplo os projectos Coupled Model Intercomparison Project, o Coordinated Regional Climate Downscaling Experiment (CORDEX), e o FPS-Convection, cujas simulações possuem resoluções desde centenas a unidades de quilómetros. Contudo, antes das simulações poderem ser usadas para realizar com confiança e robustez projeções do clima futuro é crucial avaliar a sua capacidade de representar o clima presente, tornando-se assim necessário proceder à sua avaliação. Uma das metodologias usadas na avaliação de modelos climáticos baseia-se na quantificação do valor acrescentado das simulações de alta resolução em comparação com as de baixa resolução. Para tal são necessários dados observacionais de estações meteorológicas, em grelhas regulares ou de reanálises de alta qualidade. Este tipo de avaliação permite inferir se os modelos regionais de alta resolução têm a capacidade de representar as principais variáveis como a precipitação, temperatura e extremos associados de uma forma melhorada. | pt |
| dc.description.abstract | Climate change, driven by greenhouse gas emissions and land-use changes from human activities, poses significant challenges for both the environment and humanity and is now recognized as one of the greatest challenges of the 21st century. For assessing both present and future climates, scientist developed climate models with increasing resolutions. The climate models result must be evaluated, where one paramount methodology involves quantifying the added value of high-resolution simulations, using observational data from meteorological stations, observational gridded datasets, or reanalyses as a reference. For Iberia, the regional simulations generally show added value over their forcing models, particularly in precipitation and extreme events. Nonetheless, challenges remain in modelling minimum temperature, especially due to feedback between snow, albedo, and temperature. For an alpine domain, simulations with very high kilometre resolutions, demonstrated limited improvements, particularly for temperature extremes. Despite these limitations, high-resolution models provide valuable insights into local atmospheric circulations and land-ocean interactions, crucial for accurate regional climate assessments. Among all climate extremes, droughts stand as one of the most impactful. In this context a new daily drought index is introduced, which presents a simpler and more computationally efficient method for analysing droughts, particularly for regions with high climate variability, making it a robust tool for climate simulations from the large to the local scales. Afterwards an ensemble index is considered to evaluate future projections for drought throughout 21st century over the Iberian Peninsula, in which the simulations considered were previously evaluated. Overall, projections suggest increases in drought severity, frequency, and duration, particularly under the most severe scenario. Although the region is naturally adapted to short droughts, prolonged events pose serious threats to agriculture, water resources, and ecosystems. In contrast, the most optimistic scenario indicates that late-century drought characteristics could resemble historical patterns, reinforcing the urgency of climate change mitigation strategies. | en |
| dc.format | application/pdf | |
| dc.identifier.tid | 101661762 | |
| dc.identifier.uri | http://hdl.handle.net/10400.5/116940 | |
| dc.language.iso | eng | |
| dc.subject | Climate Change | |
| dc.subject | Simulations | |
| dc.subject | Added Value | |
| dc.subject | Drought | |
| dc.subject | Alterações Climáticas | |
| dc.subject | Simulações | |
| dc.subject | Valor Acrescentado | |
| dc.subject | Seca | |
| dc.title | From the added value of regional and convective climate simulations to a new insight into drought assessment | en |
| dc.type | doctoral thesis | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess |
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