Towards downscaling of aerosol gridded dataset for improving solar resource assessment, an application to Spain

Solar radiation estimates with clear sky models require estimations of aerosol data. The low spatial resolution of current aerosol datasets, with their remarkable drift from measured data, poses a problem in solar resource estimation. This paper proposes a new downscaling methodology by combining support vector machines for regression (SVR) and kriging with external drift, with data from the MACC reanalysis datasets and temperature and rainfall measurements from 213 meteorological stations in continental Spain. The SVR technique was proven efficient in aerosol variable modeling. The Linke turbidity factor (TL) and the aerosol optical depth at 550 nm (AOD 550) estimated with SVR generated significantly lower errors in AERONET positions than MACC reanalysis estimates. The TL was estimated with relative mean absolute error (rMAE) of 10.2% (compared with AERONET), against the MACC rMAE of 18.5%. A similar behavior was seen with AOD 550, estimated with rMAE of 8.6% (compared with AERONET), against the MACC rMAE of 65.6%. Kriging using MACC data as an external drift was found useful in generating high resolution maps (0.05° × 0.05°) of both aerosol variables. We created high resolution maps of aerosol variables in continental Spain for the year 2008. The proposed methodology was proven to be a valuable tool to create high resolution maps of aerosol variables (TL and AOD 550). This methodology shows meaningful improvements when compared with estimated available databases and therefore, leads to more accurate solar resource estimations. This methodology could also be applied to the prediction of other atmospheric variables, whose datasets are of low resolution.

Study of PM10 and PM2.5 levels in three European cities: Analysis of intra and inter urban variations

In the present paper, 1-year PM10 and PM 2.5 data from roadside and urban background monitoring stations in Athens (Greece), Madrid (Spain) and London (UK) are analysed in relation to other air pollutants (NO,NO2,NOx,CO,O3 and SO2)and several meteorological parameters (wind velocity, temperature, relative humidity, precipitation, solar radiation and atmospheric pressure), in order to investigate the sources and factors affecting particulate pollution in large European cities. Principal component and regression analyses are therefore used to quantify the contribution of both combustion and non-combustion sources to the PM10 and PM 2.5 levels observed. The analysis reveals that the EU legislated PM 10 and PM2.5 limit values are frequently breached, forming a potential public health hazard in the areas studied. The seasonal variability patterns of particulates varies among cities and sites, with Athens and Madrid presenting higher PM10 concentrations during the warm period and suggesting the larger relative contribution of secondary and natural particles during hot and dry days. It is estimated that the contribution of non-combustion sources varies substantially among cities, sites and seasons and ranges between 38-67% and 40-62% in London, 26-50% and 20-62% in Athens, and 31-58% and 33-68% in Madrid, for both PM10 and PM 2.5. Higher contributions from non-combustion sources are found at urban background sites in all three cities, whereas in the traffic sites the seasonal differences are smaller. In addition, the non-combustion fraction of both particle metrics is higher during the warm season at all sites. On the whole, the analysis provides evidence of the substantial impact of non-combustion sources on local air quality in all three cities. While vehicular exhaust emissions carry a large part of the risk posed on human health by particle exposure, it is most likely that mitigation measures designed for their reduction will have a major effect only at traffic sites and additional measures will be necessary for the control of background levels. However, efforts in mitigation strategies should always focus on optimal health effects.

Sistema autónomo para carga de baterías mediante una instalación fotovoltaica con aplicación directa al vehículo eléctrico y usos

La situación energética actual es insostenible y como consecuencia se plantea un escenario próximo orientado a conseguir un futuro energético sostenible que permita el desarrollo económico y el bienestar social. La situación ambiental actual está afectada directamente por la combustión de combustibles fósiles que en 2013 constituyeron el 81% de la energía primaria utilizada por el ser humano y son la principal fuente antropogénica de gases de efecto invernadero. Los informes del IPCC1, ponen de manifiesto que el cambio climático se ha consolidado durante los últimos años y en la conferencia de la ONU sobre cambio climático de París que se celebrará a finales de 2015, se pretende que los gobiernos suscriban un acuerdo universal para limitar las emisiones de gases de efecto invernadero y evitar que el incremento de la temperatura media global supere los 2°C. Por otra parte, en el interior de las ciudades es especialmente preocupante, por su efecto directo sobre la salud humana, el impacto ambiental producido por las emisiones de NOx que generan el transporte de personas y mercancías. El sector del transporte fue responsable en 2012 del 27,9% del consumo final de energía. Una vez expuesto el escenario energético y ambiental actual, en esta tesis, se analiza la eficiencia de un sistema autónomo fotovoltaico para la carga de baterías de vehículos eléctricos y el uso del mismo con otras cargas, con el objetivo de aprovechar al máximo la energía eléctrica generada y contribuir a la utilización de energía limpia que no produzca impacto ambiental. Como primer paso para el desarrollo de la tesis se hizo un estudio de trabajos previos comenzando por las primeras aplicaciones de la energía fotovoltaica en los vehículos solares para después pasar a trabajos más recientes enfocados al suministro de energía a los vehículos eléctricos. También se hizo este estudio sobre las metodologías de simulación en los sistemas fotovoltaicos y en el modelado de distintos componentes. Posteriormente se eligieron, dentro de la amplia oferta existente en el mercado, los componentes con características técnicas más adecuadas para este tipo de instalaciones y para las necesidades que se pretenden cubrir. A partir de los parámetros técnicos de los componentes elegidos para configurar la instalación autónoma y utilizando modelos contrastados de distintos componentes, se ha desarrollado un modelo de simulación en ordenador del sistema completo con el que se han hecho simulaciones con distintos modos de demanda de energía eléctrica, según los modos de carga disponibles en el vehículo eléctrico para corriente alterna monofásica de 230 V. También se han simulado distintos tamaños del generador fotovoltaico y del sistema de acumulación de energía eléctrica para poder determinar la influencia de estos parámetros en los balances energéticos del sistema. Utilizando recursos propios el doctorando ha realizado la instalación real de un sistema fotovoltaico que incluye sistema de acumulación e inversor en un edificio de su propiedad. Para la realización de la tesis, La Fundación de Fomento e Innovación Industrial (F2I2) ha facilitado al doctorando un dispositivo que permite realizar la alimentación del vehículo eléctrico en modo 2 (este modo emplea un adaptador que incorpora dispositivos de seguridad y se comunica con el vehículo permitiendo ajustar la velocidad de recarga) y que ha sido necesario para los trabajos desarrollados. Se ha utilizado la red eléctrica como sistema de apoyo de la instalación fotovoltaica para permitir la recarga en el modo 2 que requiere más potencia que la proporcionada por el sistema fotovoltaico instalado. Se han analizado mediante simulación distintos regímenes de carga que se han estudiado experimentalmente en la instalación realizada, a la vez que se han hecho ensayos que se han reproducido mediante simulación con los mismos valores de radiación solar y temperatura con objeto de contrastar el modelo. Se han comparado los resultados experimentales con los obtenidos mediante simulación con objeto de caracterizar el comportamiento del sistema de acumulación (energía eléctrica suministrada y tensión de salida en las baterías) y del generador fotovoltaico (energía eléctrica fotovoltaica suministrada). Por último, se ha realizado un estudio económico de la instalación autónoma fotovoltaica ejecutada y simulada. En el mismo se ha planteado la utilización de fondos propios (como realmente se ha llevado a cabo) y la utilización de financiación, para determinar dos posibles escenarios que pudieran ser de utilidad a un propietario de vehículo eléctrico. Se han comparado los resultados obtenidos en los dos escenarios propuestos del estudio económico del sistema, en cuanto a los parámetros de tiempo de retorno de la inversión, valor actual neto de la inversión y tasa interna de retorno de la misma. Las conclusiones técnicas obtenidas, permiten la utilización del sistema con los modos de carga ensayados y otro tipo de cargas que aprovechen la generación eléctrica del sistema. Las baterías ofrecen mejor comportamiento cuando el aporte fotovoltaico está presente, pero no considera adecuado la conexión de cargas elevadas a un sistema de acumulación de gel (plomo-acido) como el que se ha utilizado, debido al comportamiento de este tipo de baterías ante demandas de intensidad de corriente eléctrica elevadas. Por otra parte, el comportamiento de este tipo de baterías con valores de intensidad de corriente eléctrica inferiores a 10 A en ausencia de energía fotovoltaica, con el objetivo de utilizar la generación de energía eléctrica diaria acumulada en el sistema, sí resulta interesante y ofrece un buen comportamiento del sistema de acumulación. Las circunstancias actuales de mercado, que carece de sistemas de acumulación de litio con precios de compra interesantes, no han permitido poder experimentar este sistema de acumulación en la instalación autónoma fotovoltaica ejecutada, tampoco se ha podido obtener el favor de ningún fabricante para ello. Actualmente hay disponibles sistemas de acumulación en litio que no se comercializan en España y que serían adecuados para el sistema de acumulación de energía propuesto en este estudio, que deja abierta las puertas para futuros trabajos de investigación. Las conclusiones económicas obtenidas, rentabilizan el uso de una instalación autónoma fotovoltaica con consumo instantáneo, sin acumulación de energía eléctrica. El futuro de conexión a red por parte de estas instalaciones, cuando se regule, aportará un incentivo económico para rentabilizar con menos tiempo las instalaciones autónomas fotovoltaicas, esto también deja la puerta abierta a futuros trabajos de investigación. El sistema de acumulación de energía aporta el mayor peso económico de inversión en este tipo de instalaciones. La instalación estudiada aporta indicadores económicos que la hacen rentable, pero se necesitaría que los precios de acumulación de la energía en sistemas eficientes estén comprendidos entre 100-200 €/kWh para que el sistema propuesto en este trabajo resulte atractivo a un potencial propietario de un vehículo eléctrico. ABSTRACT The current energy situation is untenable; it poses a scenario next focused on reaching a sustainable energy future, to allow economic development and social welfare. The environmental current situation is affected directly by the combustion of fossil fuels that in 2013 constituted 81 % of the primary energy used by the human being and they are the principal source human of greenhouse gases. The reports of the IPCC2, they reveal that the climate change has consolidated during the last years and in the conference of the UNO on climate change of Paris that will be celebrated at the end of 2015, there is claimed that the governments sign a universal agreement to limit the emission of greenhouse gases and to prevent that the increase of the global average temperature overcomes them 2°C. On the other hand, inside the cities it is specially worrying, for his direct effect on the human health, the environmental impact produced by the NOx emissions that generate the persons' transport and goods. The sector of the transport was responsible in 2012 of 27,9 % of the final consumption of energy. Once exposed the scenario and present environmental energy, in this thesis, it has analyzed the efficiency of an autonomous photovoltaic system for charging electric vehicles, and the use of the same with other workloads, with the objective to maximize the electrical energy generated and contribute to the use of clean energy that does not produce environmental impact. Since the first step for the development of the thesis did to itself a study of previous works beginning for the first applications of the photovoltaic power in the solar vehicles later to go on to more recent works focused on the power supply to the electrical vehicles. Also this study was done on the methodologies of simulation in the photovoltaic systems and in the shaped one of different components. Later they were chosen, inside the wide existing offer on the market, the components with technical characteristics more adapted for this type of facilities and for the needs that try to cover. From the technical parameters of the components chosen to form the autonomous installation and using models confirmed of different components, a model of simulation has developed in computer of the complete system with which simulations have been done by different manners of demand of electric power, according to the available manners of load in the electrical vehicle for single-phase alternating current of 230 V. Also there have been simulated different sizes of the photovoltaic generator and of the system of accumulation of electric power to be able to determine the influence of these parameters in the energy balances of the system. Using own resources the PhD student has realized a real installation of a photovoltaic system that includes system of accumulation and investing in a building of his property. For the accomplishment of the thesis, The Foundation of Promotion and Industrial Innovation (F2I2) it has facilitated to the PhD student a device that allows to realize the supply of the electrical vehicle in way 2 (this way uses an adapter that incorporates safety devices and communicates with the vehicle allowing to fit the speed of recharges) and that has been necessary for the developed works. The electrical network has been in use as system of support of the photovoltaic installation for allowing it her recharges in the way 2 that more power needs that provided by the photovoltaic installed system. There have been analyzed by means of simulation different rate of load that have been studied experimentally in the realized installation, simultaneously that have done to themselves tests that have reproduced by means of simulation with the same values of solar radiation and temperature in order the model contrasted. The experimental results have been compared by the obtained ones by means of simulation in order to characterize the behavior of the system of accumulation (supplied electric power and tension of exit in the batteries) and of the photovoltaic generator (photovoltaic supplied electric power). Finally, there has been realized an economic study of the autonomous photovoltaic executed and simulated installation. In the same one there has appeared the utilization of own funds (since really it has been carried out) and the utilization of financing, to determine two possible scenes that could be of usefulness to an owner of electrical vehicle. There have been compared the results obtained in both scenes proposed of the economic study of the system, as for the parameters of time of return of the investment, current clear value of the investment and rate hospitalizes of return of the same one. The technical obtained conclusions, they make the utilization of the system viable with the manners of load tested and another type of loads of that they take advantage the electrical generation of the system. The batteries offer better behavior when the photovoltaic contribution is present, but he does not consider to be suitable the connection of loads risen up to a system of accumulation of gel (lead - acid) as the one that has been in use, due to the behavior of this type of batteries before demands of intensity of electrical current raised. On the other hand, the behavior of this type of batteries with low values of intensity of electrical current to 10 To in absence of photovoltaic power, with the aim to use the generation of daily electric power accumulated in the system, yes turns out to be interesting and offers a good behavior of the system of accumulation. The current circumstances of market, which lacks systems of accumulation of lithium with interesting purchase prices, have not allowed to be able to experience this system of accumulation in the autonomous photovoltaic executed installation, neither one could have obtained the favor of any manufacturer for it. Nowadays there are available systems of accumulation in lithium that is not commercialized in Spain and that they would be adapted for the system of accumulation of energy proposed in this study, which makes the doors opened for future works of investigation. The economic obtained conclusions; they make more profitable the use of an autonomous photovoltaic installation with instantaneous consumption, without accumulation of electric power. The future of connection to network on the part of these facilities, when it is regulated, will contribute an economic incentive to make profitable with less time the autonomous photovoltaic facilities, this also leaves the door opened for future works of investigation. The system of accumulation of energy contributes the major economic weight of investment in this type of facilities. The studied installation contributes economic indicators that make her profitable, but it would be necessary that the prices of accumulation of the energy in efficient systems are understood between 100-200 € in order that the system proposed in this work turns out to be attractive to a proprietary potential of an electrical vehicle.

Analytical study of the thermal behaviour and stability of a small satellite

In this work the thermal analysis of a small satellite orbiting around the Earth has been approached by direct integration of the heat balance equations of a two-node reduced model, obtaining a linearized second order ODE problem, similar in form to the classical case of the forced vibration of a damped system. As the thermal loads (solar radiation, albedo, etc.) are harmonic, the problem is solved by means of Fourier analysis methods. Research on that field can be directly applied to the analysis of thermal problems and the results obtained are satisfactory. Working on the frequency domain streamlines the analysis, simplifies the study and facilitates the experimental testing. The transfer functions are obtained for the two-node case but the study can be extended to an n-node model.

Case study of the effects of atmospheric aerosols and regional haze on agriculture: An opportunity to enhance crop yields in China through emission controls?

The effect of atmospheric aerosols and regional haze from air pollution on the yields of rice and winter wheat grown in China is assessed. The assessment is based on estimates of aerosol optical depths over China, the effect of these optical depths on the solar irradiance reaching the earth’s surface, and the response of rice and winter wheat grown in Nanjing to the change in solar irradiance. Two sets of aerosol optical depths are presented: one based on a coupled, regional climate/air quality model simulation and the other inferred from solar radiation measurements made over a 12-year period at meteorological stations in China. The model-estimated optical depths are significantly smaller than those derived from observations, perhaps because of errors in one or both sets of optical depths or because the data from the meteorological stations has been affected by local pollution. Radiative transfer calculations using the smaller, model-estimated aerosol optical depths indicate that the so-called “direct effect” of regional haze results in an ≈5–30% reduction in the solar irradiance reaching some of China’s most productive agricultural regions. Crop-response model simulations suggest an ≈1:1 relationship between a percentage increase (decrease) in total surface solar irradiance and a percentage increase (decrease) in the yields of rice and wheat. Collectively, these calculations suggest that regional haze in China is currently depressing optimal yields of ≈70% of the crops grown in China by at least 5–30%. Reducing the severity of regional haze in China through air pollution control could potentially result in a significant increase in crop yields and help the nation meet its growing food demands in the coming decades.

Modelagem de um secador solar de produtos agrícolas com sistema de armazenagem de energia térmica

Nos países em desenvolvimento, como o Brasil, a secagem de produtos agrícolas com uso de secador solar representa uma alternativa promissora de baixo custo, reduzindo perdas e agregando valor aos produtos. Porém, devido à natureza periódica da radiação solar e das condições do tempo, nem sempre é viável sua utilização. Dessa forma, o objetivo do trabalho foi a modelagem de um sistema auxiliar de armazenagem de energia térmica (SAET) em um secador solar, cuja finalidade é armazenar energia durante o dia para ser utilizada conforme necessário. Com base em registros de temperatura e umidade relativa, ambas do ar, de um secador solar, foi feito um estudo da termodinâmica dos processos envolvidos, a fim de propor meios para o dimensionamento do SAET. Foram explorados a estimativa do fluxo de massa de ar no secador, a modelagem da temperatura em função da radiação, e o dimensionamento para diferentes modos de operação do SAET, considerando o sistema ideal. Este dimensionamento tratou tanto do caso de fornecimento contínuo de fluxo de água preaquecida, como de uso de automação para controlar o fluxo. A estimativa de fluxo de ar no secador se aproximou de valores típicos encontrados na literatura. O dimensionamento do sistema, embora considerado ideal, mostra que a utilização do SAET melhora o desempenho do secador, servindo como parâmetro para melhor compreender o comportamento das variáveis durante seu funcionamento.

Vulnerabilidade à queda de árvores por meio de simulações microclimáticas

Muitos são os benefícios provenientes da arborização de vias públicas, como aumento da vida útil do asfalto por meio do sombreamento, filtragem de poluentes, absorção de CO2, interceptação da água da chuva e da radiação solar e mitigação de ilhas de calor; porém, por questões culturais, é considerada muitas vezes pela população como algo negativo, cujas folhas entopem calhas, raízes destroem calçadas, troncos e folhas atrapalham fiação elétrica e, principalmente, elas estão susceptíveis às quedas. A pesquisa teve como objetivo estudar o comportamento das quedas de árvores no município de Piracicaba/SP, Brasil, com atenção especial ao regime de ventos na cidade, baseado em dados fornecidos pelo Corpo de Bombeiros de Piracicaba, Secretaria de Defesa do Meio Ambiente de Piracicaba (SEDEMA) e Estação Meteorológica da Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ). De caráter inédito, o principal resultado foi a relação direta entre quedas e zonas urbanizadas, que, em constantes alterações no uso do solo, acabam por danificar a sustentação das árvores (raízes), fato justificado pela alta concentração de quedas na parte central (36,7%), com destaque para as estações da primavera e do verão, ou seja, ventos e chuvas, na qual, juntas, somaram 78,0% do total. O período de retorno esperado para ventos superiores a 75 km h-1, classificados como temporais na Escala de Vento de Beaufort, foi de 2,8 eventos por ano. Enquanto verificou-se o predomínio de ventos alísios de sudeste, pertencentes ao quarto quadrante, a direção das rajadas de vento teve maior variação e, assim, com predomínio daqueles ventos, é recomendável instalações de parques industriais nas zonas norte, noroeste e oeste, haja vista a importância de evitar que os poluentes adentrem a cidade. As espécies de maior vulnerabilidade foram: Pachira aquatica Aubl. (monguba), Handroanthus sp. (ipê roxo) e Tipuana tipu (Benth.) Kuntze (tipuana). Por meio de simulação microclimática computacional, utilizando o programa ENVI-met versão 3.1, em dois estudos de caso, sendo um em bairro residencial e outro na Praça José Bonifácio, foi possível identificar locais de maior atenção quanto às quedas de árvores, em função da rugosidade do local, capaz de alterar a velocidade e a direção do vento.

Characterising the three-dimensional ozone distribution of a tidally locked Earth-like planet

We simulate the 3D ozone distribution of a tidally locked Earth-like exoplanet using the high-resolution, 3D chemistry climate model CESM1(WACCM) and study how the ozone layer of a tidally locked Earth (TLE) (ΩTLE = 1/365 days) differs from that of our present-day Earth (PDE) (ΩPDE = 1/1 day). The middle atmosphere reaches a steady state a symptotically within the first 80 days of the simulation. An upwelling, centred on the subsolar point, is present on the day side while a downwelling, centred on the antisolar point, is present on the night side. In the mesosphere, we find similar global ozone distributions for the TLE and the PDE, with decreased ozone on the day side and enhanced ozone on the night side. In the lower mesosphere, a jet stream transitions into a large-scale vortex around a low-pressure system, located at low latitudes of the TLE night side. In the middle stratosphere, the concentration of odd oxygen is approximately equal to that of the ozone [(Ox) ≈ (O3)]. At these altitudes, the lifetime of odd oxygen is ~16 h and the transport processes significantly contribute to the global distribution of stratospheric ozone. Compared to the PDE, where the strong Coriolis force acts as a mixing barrier between low and high latitudes, the transport processes of the TLE are governed by jet streams variable in the zonal and meridional directions. In the middle stratosphere of the TLE, we find high ozone values on the day side, due to the increased production of atomic oxygen on the day side, where it immediately recombines with molecular oxygen to form ozone. In contrast, the ozone is depleted on the night side, due to changes in the solar radiation distribution and the presence of a downwelling. As a result of the reduced Coriolis force, the tropical and extratropical air masses are well mixed and the global temperature distribution of the TLE stratosphere has smaller horizontal gradients than the PDE. Compared to the PDE, the total ozone column global mean is reduced by ~19.3 %. The day side and the night side total ozone column means are reduced by 23.21 and 15.52 %, respectively. Finally, we present the total ozone column (TOC) maps as viewed by a remote observer for four phases of the TLE during its revolution around the star. The mean TOC values of the four phases of the TLE vary by up to 23 %.

Earth-atmosphere radiation budget analyses derived from NOAA satellite data, June 1974-February 1978 /

Mode of access: Internet.

Solar radio emission; spectral observations in the decameter range, 24 July 1959-28 February 1961.

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Mode of access: Internet.

Solar treatments for reducing survival of mountain pine beetle in infested ponderosa and lodgepole pine logs /

"September 2001."