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354 p. Más del 98% de la población europea está expuesta a niveles nocivos de ozono troposférico según la OMS. En el Sur de Europa, la situación es todavía más grave debido a que, las mayores temperaturas y horas de luz solar que se registran en la época estival incrementan la producción fotoquímica de este contaminante secundario. La elaboración de estrategias efectivas de reducción de ozono requiere un mayor conocimiento de mecanismos de producción y transporte de este contaminante. En esta tesis doctoral se muestra cómo la combinación de sistemas de modelización meteorológicos-fotoquímicos de última generación junto con datos experimentales permite identificar y cuantificar los principales mecanismos de transporte y producción de ozono en la Península Ibérica. Se han analizado dos episodiosocurridos en julio de 2016 y agosto de 2018, prestando especial atención a la situación característica de la Comunidad Autónoma del País Vasco como caso de estudio. Los resultados muestran el transporte de ozono y/o precursores de ozono desde la costa atlántica francesa y cuencas aéreas contiguas hacia esta región. También se ha documentado el transporte entre las distintas cuencas de la Península Ibérica (Valle del Ebro, Duero, Tajo y Guadalquivir) y el impacto del ozono producido en las regiones periféricas receptoras de las zonas metropolitanas de Madrid, Barcelona y Lisboa. Además, se han cuantificado las aportaciones a través de las principales vías de transporte del ozono a la Comunidad Autónoma Vasca.

This paper investigates cold outbreaks that form offshore density currents within the whole mesoscale over the Western Mediterranean basin. Reflectivity radar and satellite images are used to detect clouds and precipitation that are associated with these density currents in the meso-α, meso-β, and meso-γover the Western Mediterranean basin (WMB). Version 3.3 of the WRF-ARW model is used to describe the formation and evolution of these density currents and to estimate their lifetime as well as horizontal and vertical scales. Based on the observations and simulations, this paper suggests that a new perspective could effectively be adopted regarding the WMB region delineated by the Balearic Islands, the northeastern Iberian Peninsula, and the Gulf of Lion, where inland cold outbreaks develop into density currents that move offshore and can produce precipitation ranging from raincells to rainbands at the whole mesoscale.

As mesoscale models increase in resolution there is a greater need to understand predictability on smaller scales. The predictability of a model is related to forecast skill. It is possible that the uncertainty of one scale of motion can affect the other scales due to the nonlinearity of the atmosphere. Some suggest that topography is one factor that can lead to an increase of forecast skill and therefore predictability. This study examines the uncertainty of a mesoscale model and attempts to characterize the predictability of the wind field. The data collected is from the summer, when the synoptic forcing is relatively benign. Mesoscale Model 5 (MM5) lagged forecasts are used to create a three-member ensemble over a 12-hour forecast cycle. The differences in these forecasts are used to determine the spread of the wind field. Results show that some mesoscale features have high uncertainty and others have low uncertainty, shedding light on the potential predictability of these features with a mesoscale model. Results indicate that topography is a large source of uncertainty. This is seen in all data sets, contrary to other studies. The ability of the model to properly forecast the diurnal cycle also impacted substantially on the character and evolution of forecast spread. The persistent mesoscale features were represented reasonably well, however the detailed structure of these features had a fair amount of uncertainty. http://archive.org/details/anumericalinvest109451145 Lieutenant Junior Grade, United States Navy Approved for public release; distribution is unlimited.