Morphological, chemical and optical absorbing characterization of aerosols in the urban atmosphere of Valladolid

Samples of atmospheric aerosol particles were collected in Valladolid, Spain, during the winter of 2003–2004. The measurements were made with a Dekati PM10 cascade impactor with four size stages: greater than 10 μm, between 2.5 to 10 μm, 1 to 2.5 μm and less than 1 μm. The size and shape of the particles were analyzed with a scanning electron microscope (SEM) and elemental analysis was done with an energy dispersive x-ray analysis (EDX). We present an evaluation by size, shape and composition of the major particulate species in the Valladolid urban atmosphere. The total aerosol concentration is very variable, ranging from 39.86 μg·m−3 to 184.88 μg·m−3 with the coarse particles as the dominant mass fraction. Emphasis was given to fine particles (<1 μm), for which the visible (400 nm to 650 nm) light absorption coefficients were measured using the integrating plate technique. We have made some enhancements in the illumination system of this measurement system. The absorption coefficient, σa , is highly variable and ranges from 7.33×10−6 m−1 to 1.01×10−4 m−1 at a wavelength of 550 nm. There is an inverse power law relationship between σa and wavelength, with an average exponent of −0.8.info:eu-repo/semantics/publishedVersio

Climatología Antártica: comprendiendo los efectos a escala global

Polar regions are remote areas that have a great influence on the Earth’s climate and therefore on the environment, ecosystems, and human society. These regions are highly sensitive to climate change, which increases their importance for the future of polar ecosystems. In fact, the three areas that have experienced the fastest warming in the last two decades have been Alaska, Siberia, and the Antarctic Peninsula. The Poles act as heat sinks of the global climate system, and respond to climate changes produced anywhere else on Earth and at the same time condition themLas regiones polares son áreas remotas que tienen una gran influencia en el clima de la Tierra y por tanto en el medio ambiente, los ecosistemas, y la sociedad humana. Estas regiones son altamente sensibles al cambio climático, lo cual aumenta su importancia para el futuro de los ecosistemas polares. De hecho, las tres zonas que han sufrido el calentamiento más rápido en las dos últimas décadas han sido Alaska, Siberia, y la Península Antártica. Los Polos actúan como sumideros de calor del sistema climático global, y responden a los cambios climáticos producidos en cualquier otra parte de la Tierra y al mismo tiempo los condicionan.&nbsp

Morphology, Mineralogy, and Chemistry of Atmospheric Aerosols Nearby an Active Mining Area: Aljustrel Mine (SW Portugal)

Mining activities increase contaminant levels in the environment, so it is crucial to study the particulate matter in these areas to understand the impacts on nearby urban areas and populations. This work was conducted close to the active mine of Aljustrel (Portugal), where black dust deposition is evident. PM10 samples were collected in two periods: 10–17 July and 1–10 November of 2018. Two different techniques were used: SEM-EDX for the individual characterization of the aerosols and ICP-MS to quantify the elemental concentration of 11 elements (Ca, Na, Fe, Mn, As, Cd, Cu, Sb, Pb, and Zn). In this region, the observed PM10 mass concentration was 20 to 47 g m 3 (July) and 4 to 23 g m3 (November), which is lower than the limit of 50 g m3 established in the European Directive. The individual characterization of 2006 particles by SEM-EDX shows oxides (17%) and sulfides (10%), while Na, Si, Fe, S, Al, and Cu are the elements with the most representativeness in all the analyzed particles. The ICP-MS results indicate that the daily elemental concentration in the samples collected in July is higher than November, and only As exceeds the limit established for European legislation.info:eu-repo/semantics/publishedVersio

Column-integrated aerosol microphysical properties from AERONET Sun photometer over southwestern Spain

The aim of the present work is to carry out a detailed analysis of columnar microphysical properties obtained from Cimel sun-photometer measurements in the Southwest of Spain within the frame of the Aerosol Robotic Network (AERONET) – Iberian Network for aerosol measurements (RIMA). AERONET level 2 inversion products are analysed, in particular the particle size distribution together with their associated microphysical parameters for both fine and coarse modes: volume concentration, effective radius and the fine mode volume fraction. This work complements previous works based on aerosol optical depth (AOD) and the Ångström exponent (AE) for a global characterization of atmospheric aerosol in this area of southwestern Spain.Financial support from the Spanish MICINN (projects of ref. CGL2008-05939-CO3-01/CLI and CGL2009- 09740 and “Acci´on Complementaria” CGL2010-09480-E) are gratefully acknowledged

Medidas de absorción debida a los aerosoles en la estación subártica ALOMAR

The global study of atmospheric aerosol is one of the key factors in regards to climate change and those effects. Over the last 4 years a strong research work on aerosols properties characterization have been carried out into the Atmospheric Optics Group of the University of Valladolid (GOA-UVa) in Spain. We present the results about aerosol absorption coefficient measurements with two different techniques: the “integrating sphere photometer” and the particle soot absorption photometer (PSAP, Radiance Research). This data was acquired into the summer campaign 2008, made at north of Norway, like a result of the participation in-situ of GOA in the POLARCAT project, lead by the Norwegian Institute for Air Research, and included in the Fourth International Polar Year. Both methods are filter based and provide measurements that could be combined with optical column measurements for a better characterization of local aerosol. It contributes especially to the investigation of pollution events and to establishment the effects of the population over any local aerosol climatology. Based on this research background and the affordable and reliable instrumentation described in this work, the research can continue in Colombia in close collaborations with Spanish research groups.El estudio de los aerosoles atmosféricos a nivel mundial, es uno de los factores clave para entender el cambio climático y sus efectos. En los últimos 4 años, el Grupo de Óptica Atmosférica de la Universidad de Valladolid (GOA-UVa, España), ha venido realizando un importante trabajo de investigación respecto de la caracterización de las propiedades de los aerosoles. En este trabajo se presentan los resultados de las mediciones del coeficiente de absorción debida a los aerosoles con dos técnicas distintas: el fotómetro de esfera integrante y el fotómetro de absorción PSAP (Radiance Research). Estos datos fueron obtenidos durante la campaña de verano 2008 realizada al norte de Noruega, como resultado de la participación del GOA-UVa en el proyecto POLARCAT, dirigido por el Instituto Noruego para la investigación del aire y que está incluido en el cuarto año Polar Internacional. Los dos métodos utilizados están basados en las medidas sobre filtros y proporcionan medidas in situ que pueden ser combinadas con medidas sobre la columna atmosférica, para una mejor caracterización de los aerosoles locales. Este estudio contribuye especialmente a la investigación de los eventos de polución y en el establecimiento de los efectos de la población sobre la climatología local de aerosoles. Teniendo como base estos antecedentes de investigación y, la posibilidad de adquirir la asequible y fiable instrumentación descrita en este trabajo, la investigación puede continuar en Colombia en estrecha colaboración con los grupos de investigación españoles.info:eu-repo/semantics/publishedVersio

Analysis of aerosol optical depth evaluation in polar regions and associated uncertainties

Some available processing algorithms used to calculate the aerosol optical depth from radiometric measurements were tested. The aim was to evaluate the associated uncertainties in polar regions due to the data processing, in order to adjust the methodology of the calculation and illustrate the importance of these error sources. The measurements were obtained during a sun photometer campaign in Ny-Ålesund within the framework of the POLAR-AOD project

Error source in AOD retrieval from filter radiometer data in the UV due to filter band function

The filter band function of filter radiometers is frequently used in AOD retrieval to improve the accuracy of the Rayleigh and gaseous absorption contributions to the total optical depth. These contributions to the total optical thickness are overestimated when the band-pass filter curve used in the computation exceeds the lower limit of the detector response range (around 320 nm). It can be the case for some typical band-pass filters used in the ultraviolet region (e.g. 340 or 380 nm). This error can involve a strong impact on the aerosol optical depth accuracy, underestimating its value. Errors as large as 0.047 in the evaluation of ozone optical depth at 340 nm, and 0.009 in the Rayleigh optical depth were found, leading to final errors of 50–100% in the AOD for remote locations, like Polar regions or high mountains. To avoid this significant error, the detector spectral response must be taken into account in the computations. Further, it is recommended to discard the filter band-pass function when the transmittance falls below 1% of its maximum value at the central wavelength

The fictitious diurnal cycle of aerosol optical depth: A new approach for “in situ” calibration and correction of AOD data series

Aerosol optical depth (AOD) very often shows a distinct diurnal cycle pattern, which seems to be an artifact. This phenomenon is the result of a deficient calibration (or an equivalent effect, as filter degradation). The fictitious sinusoidal shape of the AOD diurnal cycle is a function of the cosine of the solar zenith angle (SZA) and its effect is more accentuated during mid-day. The observation of this effect is not easy at current field stations and only those stations with excellent weather conditions permit an easier detection and correction. By taking advantage of this diurnal cycle behavior because of its dependence on the cosine of the SZA, we propose an improved “in situ” calibration correction procedure. The method is named KCICLO because the determination of a constant K and the behavior of AOD as a cycle (ciclo, in Spanish). It can be seen as a modification of the classical Langley technique (CLT) with the same level of accuracy when CLT is applied at high-altitude stations, and results in an accuracy of 0.2–0.5% for the calibration ratio constant K (or 0.002–0.005 in AOD). The application of this correction method to current and old data series at sunny stations is a significant improvement over “in situ” methods, because no other information beyond the AOD data is necessary

Comparison between measurements and model simulations of solar radiation at a high altitude site: case studies for the Izaña BSRN Station [Póster]

Póster presentado en: International Radiation Symposium, celebrado del 6 al 10 de agosto de 2012 en Berlín, Alemania.Financial supports from the Spanish MICIIN for projects CGL2009-09740, CGL2011-23413 and CGL2010-09480E, CGL2011-13085-E are gratefully acknowledged. We authors to acknowledge the AERONET-PHOTONS-RIMA networks (http://aeronet.gsfc.nasa.gov) and the LibRadtran model (http://www.libradtran.org)

La estación BSRN de Izaña

Financial supports from the Spanish MICIIN (ref. CGL2008‐05939‐CO3‐00/CLI and CGL2009 09740) and from the GR‐220 Project of the Junta de Castilla y León are Gratefully acknowledged