The role of vegetation in regional climate simulations

Land surface atmosphere interactions are of great relevance in climate and weather. The biophysical variables of the earth’s surface play a determining role in the exchanges of heat, momentum and humidity with the atmosphere. In this way, the correct representation and understanding of how these var...

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Detalles Bibliográficos
Autor: Jiménez Gutiérrez, José Manuel
Tipo de recurso: tesis doctoral
Fecha de publicación:2023
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/4205
Acceso en línea:https://hdl.handle.net/20.500.14352/4205
Access Level:acceso abierto
Palabra clave:52-33(043.2)
Astrophysics
Astrofísica
Descripción
Sumario:Land surface atmosphere interactions are of great relevance in climate and weather. The biophysical variables of the earth’s surface play a determining role in the exchanges of heat, momentum and humidity with the atmosphere. In this way, the correct representation and understanding of how these variables perform in Land Surface Models (LSMs) is crucial for the modeling of atmospheric processes. Vegetation variability in its spatial and vertical dimension as well as the state, health or type of vegetation is described in the numerical prediction models by parameters such as albedo, fraction of vegetation cover (FVC), leaf area index (LAI), stomatal resistance, conductivity or roots depth. The variable FVC represents the horizontal density of live vegetation and is calculated through the Normalized Dierence Vegetation Index (NDVI). FVC defines how total evaporation is partitioned between evaporation from the soil and transpiration from plants. In some LSMs it has a decreasing effect on thermal conductivity, thus reducing heat transfer to deeper layers of the soil. These physical processes determine in a decisive way surface variables such as air temperature or relative humidity. For this reason,the variability in precipitation, fires or anthropogenic changes in the vegetation cover imply a temporal and spatial heterogeneity of the FVC that have a not negligible impact in numerical simulations...