Continental surface water and energy budgets in the XX and XXI centuries

Tese de doutoramento, Ciências Geofísicas e da Geoinformação (Meteorologia), Universidade de Lisboa, Faculdade de Ciências, 2015

The global water cycle is an integral part of the Earth system, playing a central role in our climate and controlling the global energy cycle as well as carbon, nutrient, and sediment cycles. The development of hydrological models and respective driving forcing allows a better knowledge of the land surface. There are a diversity of hydrological models and approaches, ranging from conceptually based lumped models to distributed physically based hydrology models. This range was developed in response to many different requirements in terms of scale, purpose, and availability data. Model intercomparison efforts have helped to reveal the strengths and weaknesses of the individual models. This exercise provides useful feedback to modellers and improved our understanding of the water cycle. Aspects like seasonal and interannual behaviour were analysed improving our knowledge about the land surface modelling. The methods and datasets developed in this thesis allow us to make estimates of past and future global water availability. The forcing data were used as input to hydrological and land surface models to produce comprehensive global water cycle data sets, which were also validated. The global water cycle data sets also provided invaluable historical data for areas of the world where little data or no observed climate and hydrological data exist. The first step was the production of the WATCH Forcing Data, merging a 3-hourly reanalysis and monthly observations. The forcing data were then used as input to hydrological and land surface models, producing an ensemble of global water and energy cycle datasets. The use of this data assessed the hydrology of continental surface, focus on Europe. The main purpose of this thesis was to provide a more consistent analysis of components of the terrestrial surface water and energy budgets for the twentieth and twentieth-first centuries. The forcing data is available to everyone.

Fundação para a Ciência e a Tecnologia (FCT), SFRH/BD/76852/2011; Projeto Water and Global Change (WATCH, 2007-2011)