Gregorio Maqueda

Vertical structure of the stable boundary layer detected by RASS-SODAR and in-situ measurements in SABLES 2006 field campaign

Data from the SABLES 2006 field campaign are used in order to analyse some of the main processes present along the nocturnal periods: surface-based inversions, low level jets, katabatic winds, wave-like motions, pressure perturbations, etc. These processes have an important influence on the vertical structure (both thermal and dynamical) of the atmospheric boundary layer, and can be better described with the synergetic combination of RASS-SODAR data and in-situ measurements (such as sonic anemometer data and high-resolution pressure series from microbarometers). It is shown how the different air masses and their evolution are easily identified when pressure and RASS-SODAR wind and temperature data are presented together. Likewise, periodic pressure fluctuations observed in the surface array of microbarometers reveal the existence of gravity wave motions whose propagation is better understood after locating the wave ducting layers with the help of RASS-SODAR average wind ant temperature profiles.

Analysis of Fractal Dimension of the Wind Speed and Its Relationships with Turbulent and Stability Parameters

© 2012 Maqueda et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Analysis of Fractal Dimension of the Wind Speed and Its Relationships with Turbulent and Stability Parameters

Application of a short term air quality action plan in Madrid (Spain) under a high-pollution episode - Part I: Diagnostic and analysis from observations

Exceedances of NO2 hourly limit value (200 μg·m-3) imply the need to implement short term action plans to avoid adverse effects on human health in urban areas. The Madrid City Council applied the stage 3 of the NO2 protocol during a high-pollution episode under stable meteorological conditions on December 2016 for the first time. This included road traffic access restrictions to the city centre (50% of conventional private vehicles based on plate numbers). In this contribution we analyse different meteorological and air quality observations, including non-standard parameters (such as number of ultrafine particles and remote sensing techniques MAXDOAS) for a better understanding of the effectivity of short-term emission abatement measures under real conditions and to identify options to improve the NO2 protocol in the future. According to our results, the inversion base height computed from vertical temperature soundings is a meaningful index to anticipate very unfavourable conditions and trigger the actions included in the protocol. The analysis of the concentration levels of the main pollutants from the Madrid air quality monitoring network indicate that only stage 3 of the protocol had a significant effect on NO2 maximum concentrations. The restrictions applied may have prevented NO2 concentrations to further increase in the city centre (up to 15%) although pollution levels in the city outskirts, outside the area directly affected by the traffic restrictions, remained unchanged or may have been slightly increased. Nonetheless, further studies are needed to estimate more precisely the effect of the measures taken and to assess potential trade-offs. Our results suggest that emissions play an important role also under very strong stability conditions although drastic measures are needed to achieve a significant impact. This highlights the importance of an appropriate timing for short-term actions and the need of permanent abatement measures related to air quality plans and policies.

Análisis del Comportamiento de un Chorro Turbulento en un Recinto Cerrado

Se estudia la estructura de un chorro no isotermico introducido en el interior de una celda de geometria sencilla, que representa una habitacion a escala real, y el intercambio de calor por transporte turbulento asociado al chorro. Utilizando una base de datos de velocidad obtenida con anemometros sonico y de hilo caliente, asi como de temperatura con termopares, se calcula el numero de Arquimedes (Ar), la anchura termica del flujo (lm) y los numeros adimensionales de Rayleigh (Ra) y Nusselt (Nu). Se determina la intensidad de turbulencia y los flujos de momento y calor, realizando el analisis de la varianza con el objetivo de contrastar la dependencia considerada, entre estos parametros, segun criterios de significacion estadistica. Los resultados muestran el comportamiento de las fuerzas de origen termico y de inercia estan asociados al chorro y al transporte de calor de origen turbulento en el interior de la celda.