Editorial for the special issue “Remote sensing of atmospheric components and water vapor”

Producción CientíficaThe observation/monitoring of atmospheric components and water vapor in the atmosphere is today open to very different remote sensing techniques, most of them based on the radiation-matter interaction covering the full electromagnetic spectrum. This SI collects some papers regarding the retrieval, calibration, validation, analysis of data and uncertainties, as well as comparative studies on atmospheric gases and water vapor by remote sensing techniques, where different types of sensors, instruments, and algorithms are used or developedMinisterio de Ciencia, Innovación y Universidades (RTI2018-097864-B-I00)Junta de Extremadura - FEDER (IB18092

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

The BSRN twin-stations: IZAÑA (IZA) and SANTA CRUZ (SCO)

Comunicación presentada en: 11th BSRN Scientific Review and Workshop celebrado del 13 al 16 de abril de 2010 en Queenstown, Nueva Zelanda

Evaluation of Water Vapor Radiative Effects Using GPS Data Series over Southwestern Europe

Producción CientíficaWater vapor radiative effects (WVRE) at surface in the long-wave (LW) and short-wave (SW) spectral ranges under cloud and aerosol free conditions are analyzed for seven stations in Spain over the 2007–2015 period. WVRE is calculated as the difference between the net flux obtained by two radiative transfer simulations; one with water vapor from Global Positioning System (GPS) measurements and the other one without any water vapor (dry atmosphere). The WVRE in the LW ranges from 107.9Wm2 to 296.7Wm−2 , while in the SW it goes from −64.9Wm−2 to −6.0Wm−2 . The results show a clear seasonal cycle, which allows the classification of stations in three sub-regions. In general, for total (SW + LW) and LW WVRE, winter (DJF) and spring (MAM) values are lower than summer (JJA) and autumn (SON). However, in the case of SW WVRE, the weaker values are in winter and autumn, and the stronger ones in summer and spring. Positive trends for LW (and total) WVRE may partially explain the well-known increase of surface air temperatures in the study region. Additionally, negative trends for SW WVRE are especially remarkable, since they represent about a quarter of the contribution of aerosols to the strong brightening effect (increase of the SW radiation flux at surface associated with a reduction of the cloud cover and aerosol load) observed since the 2000s in the Iberian Peninsula, but with opposite sign, so it is suggested that water vapor could be partially masking the full magnitude of this brightening.Ministerio de Economía, Industria y Competitividad (grant CGL2017-87917-P)Junta de Extremadura - Fondo Europeo de Desarrollo Regional (grant IB18092)Ministerio de Ciencia, Innovación y Universidades (project RTI2018-097864-B-I00 and fellowship RYC-2016–20784)Junta de Extremadura - Fondo Social Europeo (fellowship PD18029

Improvement in PWV estimation from GPS due to the absolute calibration of antenna phase center variations

Climatology of column-integrated atmospheric water vapor over Spain has been carried out by means of three techniques: soundings, sun photometers and GPS receivers. Comparing data from stations equipped with more than one of these instruments, we found that a large discontinuity occurred on November 6, 2006, in the differences between the data series from GPS receivers and those from the other two techniques. Prior to that date, the GPS data indicate a wet bias of 2–3 mm for all stations when compared with sounding or photometer data, whereas after that date this bias practically reduces to zero. The root mean square error also decreases about half of its value. On November 6, 2006, the International GNSS Service adopted an absolute calibration model for the antennas of the GPS satellites and receivers instead of the relative one. This change is expected to be an improvement, increasing the accuracy of station position determination and consequently benefiting post-processing products such as zenith total delay from which the atmospheric water vapor content is calculated

Columnar aerosol characterization over Scandinavia and Svalbard

An overview of sun photometer measurements of aerosol properties in Scandinavia and Svalbard was provided by Toledano et al. (2012) thanks to the collaborative effort of various research groups from different countries that maintain a number of observation sites in the European Arctic and sub-Arctic regions. The spatial coverage of this kind of data has remarkably improved in the last years, thanks, among other things, to projects carried out within the framework of the International Polar Year 2007-08. The data from a set of operational sun photometer sites belonging either to national or international measurement networks (AERONET, GAW-PFR) were evaluated. The direct sun observations provided spectral aerosol optical depth (AOD) and Ångström exponent (AE), that are parameters with sufficient long-term records for a first characterization at all sites. At the AERONET sites, microphysical properties derived from inversion of sun-sky radiance data were also examined. AOD (500nm) ranged from 0.08 to 0.10 in Arctic and sub-Arctic sites whereas the aerosol load was higher in more populated areas in Southern Scandinavia (average AOD about 0.10–0.12 at 500 nm).Financial support was provided by: the Spanish CICYT (CGL2008-05939-CO3-01/CLI, CGL2009-09740 and CGL2011-13085-E); the Norwegian Research Council for POLARCAT-Norway; and the Swedish National Space Board and ESA for Norrköping and Palgrunden sites. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement Nr. 262254 [ACTRIS]

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

A first comparison between Almucantar and principal plane retrieval products within AERONET network

Resumen de la comunicación oral presentada en: 1st Iberian Meeting on Aerosol Science and Technology – RICTA 2013, celebrado del 1 al 3 de julio de 2013 en Évora, Portugal

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