19 research outputs found

    La Red de Ozono Superficial de Canarias: R.O.C.A.

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    Ponencia presentada en: 1er Encuentro sobre Meteorología y Atmósfera de Canarias, celebrado en el Puerto de la Cruz, los días 12,13 y 14 de noviembre de 2003. El encuentro estuvo organizado por el Centro Meteorológico Territorial en Canarias Occidental, con la colaboración del Observatorio Atmosférico de Izaña y del Grupo de Física de la Atmósfera de la Facultad de Física (Universidad de La Laguna)En este trabajo se presenta la Red de Ozono superficial de Canarias (R. O. C.A.) configurada a partir de una serie de estaciones operativas en algunas islas del archipiélago y dedicadas a la medida y seguimiento de /as concentraciones de este gas traza atmosférico. Actualmente estas estaciones están siendo gestionadas por el Observatorio Atmosférico de /zaña y por el Grupo de Física de la Atmósfera y Medio Ambiente de la Universidad de La Laguna, dentro del marco de diferentes programas y proyectos de vigilancia de la atmósfera. Se analizarán detalladamente /as principales características de /as diferentes estaciones con /as que cuenta la red, de la instrumentación de cada estación, de /os medios y técnicas de calibración, así como del software específico desarrollado para el tratamiento informático de los datos suministrados por las diferentes estaciones

    Diffractive optical devices produced by light-assisted trapping of nanoparticles

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    © 2015 Optical Society of America.]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibitedOne and two-dimensional diffractive optical devices have been fabricated by light assisted trapping and patterning of nanoparticles. The method is based on the dielectrophoretic forces appearing in the vicinity of a photovoltaic crystal, such as Fe:LiNbO3, during or after illumination. By illumination with the appropriate light distribution, the nanoparticles are organized along patterns designed at will. One- and two-dimensional diffractive components have been achieved on X- and Z-cut Fe:LiNbO3 crystals, with their polar axes parallel and perpendicular to the crystal surface, respectively. Diffraction gratings with periods down to around a few micrometers have been produced using metal (Al, Ag) nanoparticles with radii in the range of 70-100 nm. Moreover, several 2D devices, such as Fresnel zone plates, have been also produced showing the potential of the method. The diffractive particle patterns remain stable when light is removed. A method to transfer the diffractive patterns to other non-photovoltaic substrates, such as silica glass, has been also reportedThis work was supported by Spanish projects MAT2011- 28379-C03 and MAT2014-57704-C0

    Origin and SEM analysis of aerosols in the high mountain of Tenerife (Canary Islands)

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    Focusing on aerosolized matter of relevance to respiratory health, a major public health issue worldwide, we studied mineral and biological aerosol (bioaerosol) composition (TSP and PM2.5) and geographical origins during dust intrusions in the Canary Islands. Seven days’ back- ward trajectories were assessed daily during March 2004 with the ends of back trajectories being the sampling station of Iza?a (high moun- tain, 2360 m a.s.l. at the Ca?adas del Teide National Park, Tenerife island), a free troposphere site allowing characterization of dust with low influence of other pollutant sources. Scanning electron microscopy (SEM) was used to survey major types of airborne particles in the dust plumes. Control, non-intrusion conditions correspond to Atlantic oceanic middle troposphere (OMT) air masses. Of the 14 samples taken, 1 corresponded to a control (clear atmosphere conditions), and the remaining 13 to dust intrusions, with the following sources: African Dust; EAM: mixture of Europe, Africa and Oceanic; MaA: maritime aerosols. Of the air masses, 79% were directly transported to the islands from Africa, and an increase of African dust events was detected when comparing with a 52-year previous data sequence. Quartz microcristals and aggregates of quartz and platy clay were the dominant minerals identified, with marine salt and gypsum also present. Freshwater diatom tests (from two Aulacoseira species) represented the most important biogenic aerosols, although fungi and pollen were also detected. The diverse and complex mixture of respirable particles in large quantities in airborne dust, especially from nearby Sahara and from the Sahelian region, is of maximum interest for air- way pathology in the Canaries, including the highly visited highlands in Tenerife.We acknowledge to the MEC (Ministry of Education and Science, Spain) and F.E.D.E.R. founds (E.U.) for the economical support of the following projects: CGL2005-03428-C04-02, CGL2007-66477-C02-02/CLI, CGL2008- 04740 and PI042005/033

    VME indicator species collected during exploratory fishing in Macaronesian seamounts

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    During the second half of 2012, the longline vessel MARANSA completed 13 fishing trips in international waters of CECAF Area (Division FAO 34), in nine Seamounts from northeast off Madeira (Lion, Ampere, Unicorn, Seine, “Camaguay”, “Cabezos”, Dacia and “Fantasma”) to south off the Canary Islands (Eco/Endeavour), between latitudes 19°N and 35°N, using bottom longlines. The main target species were demersal species such as Wreckfish (Polyprion americanus) or Splendidalfonsino (Beryx splendens). An observer on board recorded the bycatch of Vulnerable Marine Ecosystems (VME) indicator species in order to evaluate the potential adverse impact of bottom fishing activities on VME and samples of the specimens for later identification in the laboratory were stored. The main indicator species found were cold-water corals (black corals, scleractinians and gorgonians) and sponges, species broadly associated with seamounts. The shallower banks, Ampere and Dacia in the north and centre of the area, show the greater biodiversity and the higher percentage of presence of VME indicator species (52% and 53% of the sets respectively), followed by Endeavour (South of the Canary Islands), 36.4%. In these three banks the species distribution is strongly related to depth, finding Antipatharia (mainly Stichopathes sp) and Scleractinia (Dendrophyllia cornigera and D. ramea) in shallower depths and Porifera (Neophryssospongia nolitangere, Leiodermatium lynceus and Asconema setubalense) in deeper bottoms. Species of the Porifera group are present in all banks except of so-called ”Cabezos”

    Notícias e revisão da literatura

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    Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements

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    A comprehensive characterisation of atmospheric aerosols in the subtropical eastern North Atlantic has been carried out using long-term ground-based Aerosol Robotic NETwork (AERONET) photometric observations over the period 2005–2020 from a unique network made up of four stations strategically located from sea level to 3555 m on the island of Tenerife. This site can be considered a sentinel for the passage of airmasses going to Europe from Africa, and therefore the aerosol characterisation performed here adds important information for analysing their evolution during their path toward Northern Europe. Two of these stations (Santa Cruz de Tenerife – SCO – at sea level and La Laguna – LLO – at 580 m a.s.l.) are located within the marine atmospheric boundary layer (MABL), and the other two (Izaña – IZO – at 2373 m a.s.l. and Teide Peak – TPO – at 3555 m a.s.l.) are high mountain stations within the free troposphere (FT). Monthly climatology of the aerosol optical depth (AOD), Ångström exponent (AE), aerosol concentration, size distribution and aerosol optical properties has been obtained for the MABL and FT. Measurements that are quite consistent across the four sites have been used to categorise the main atmospheric scenarios, and these measurements confirm an alternation between predominant background conditions and predominant dust-loaded Saharan air mass conditions caused by seasonal dust transport over the subtropical North Atlantic. Background conditions prevail in the MABL and FT for most of the year, while dust-laden conditions dominate in July and August.The authors also acknowledge the support from ACTRIS, Ministerio de Ciencia e Innovación, Spain, through the projects SYNERA (PID2020-118793GA-I00) and ePOLAAR (RTI2018-097864-BI00) and from Junta de Castilla y León (grant no. VA227P20)

    Quantification of CH4 emissions from waste disposal sites near the city of Madrid using ground- and space-based observations of COCCON, TROPOMI and IASI

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    We use different methane ground- and space-based remote sensing data sets for investigating the emission strength of three waste disposal sites close to Madrid. We present a method that uses wind-assigned anomalies for deriving emission strengths from satellite data and estimating their uncertainty to 9–14 %. The emission strengths estimated from the remote sensing data sets are significantly larger than the values published in the official register.ESA support through the COCCON-PROCEEDS and COCCON-PROCEEDS II projects. In addition, this research was funded by the Ministerio de Economía y Competitividad from Spain through the INMENSE project (CGL2016-80688-P). This research has largely benefit from funds of the Deutsche Forschungsgemeinschaft (provided for the two projects MOTIV and TEDDY with IDs/290612604 and 416767181, respectively)

    Izaña Atmospheric Research Center. Activity Report 2015-2016

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    This report is a summary of the many activities at the Izaña Atmospheric Research Center to the broader community. The combination of operational activities, research and development in state-of-the-art measurement techniques, calibration and validation and international cooperation encompass the vision of WMO to provide world leadership in expertise and international cooperation in weather, climate, hydrology and related environmental issues
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