Caracterización de aerosoles mediante fotometría solar en el Observatorio Atmosférico de Izaña

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)La relación entre la radiación solar directa en el rango visible medida por un fotómetro solar y la cantidad de aerosoles presentes en la capa atmosférica que atraviesa, viene caracterizada por el denominado espesor óptico de aerosoles o atenuación de radiación debida a la absorción y dispersión de luz por parte de estos. Un radiómetro de filtros de precisión (PFR) de 4 canales y, recientemente, un fotómetro solar C/MEL de 8 canales, situados en el Observatorio Atmosférico de lzaña, nos proporcionan los datos necesarios para la evaluación de tales espesores. En este trabajo se presenta la serie de valores medios diarios de espesores ópticos obtenidos desde junio de 2001 hasta la actualidad con el PFR. A partir de aquí se puede correlacionar el espesor óptico de aerosoles con las frecuencias mensuales de ocurrencia de diversas situaciones meteorológicas determinadas por la llegada de diferentes masas de aire procedentes del Atlántico y de los continentes europeo y africano

Distribución por tamaños de aerosoles atmosféricos particulados en Izaña y Santa Cruz de Tenerife

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

Column water vapor determination in night period with a lunar photometer prototype

In this paper we present the preliminary results of atmospheric column-integrated precipitable water vapor (PWV) obtained with a new Lunar Cimel photometer (LC) at the high mountain Izaña Observatory in the period July–August 2011. We have compared quasi-simultaneous nocturnal PWV from LC with PWV from a Global Positioning System (GPS) receiver and nighttime radiosondes (RS92). LC data have been calibrated using the Lunar Langley method (LLM). We complemented this comparative study using quasi-simultaneous daytime PWV from Cimel AERONET (CA), GPS and RS92.The AERONET sun photometer at Izana has been calibrated within AERONET- ˜ EUROPE TNA supported by the European Community – Research Infrastructure Action under the FP7 “Capacities” specific program for Integrating Activities, ACTRIS grant agreement no. 262254

El “Tentamen medicum de morbo miliari infantum, muguet, millet, blanchet, gallico idiomate appellate" (1786), de Francisco Sanponts

A medical text on aphtae, writed in 1786 and printed in 1788, is analized. Its author was the catalan physician Francisco Sanponts y Roca (1756-1821). This work was awarded with the first prize by the Société Royal de Médecine from Paris, in a competition to study and solve the problem of the wide diffusion of Aphtae (Muguet) among the orphanages' children. This was the first description of this disease in Spain. The author was influenced by the antisystematic mentality and by the anatomoclinical empiricism; he widely refers to Van Swieten and Nils Rosen, besides other 65 authors. Through his references he proved that he was well informed about the European medicine and pediatrics, although he was not apparently acquainted with the work of Underwood, the first known description of this disease, that was published two years earlier.Se analiza un texto de 1786 impreso en 1788, cuyo autor es el médico catalán Francisco Sanponts y Roca (1756-1821), que mereció el primer premio de la Real Sociedad de Medicina de París en un certamen convocado para estudiar y solucionar el problema planteado por la amplia difusión del Muguet entre los niños acogidos en hospicios. Se trata de la primera descripción de la enfermedad hecha en España y el autor, influido por la mentalidad antisistemática y el empirismo anatomoclínico, cita de forma amplia a Van Swieten y a Nils Rosen, entre 67 autores, con lo que demuestra estar al corriente de la medicina y la pediatría europeas, aunque aparentemente desconoce el trabajo de Underwood, publicado dos años antes de la elaboración del suyo, que representa la primera descripción conocida de esta enfermedad

Continuous quality assessment of atmospheric water vapour measurement techniques: FTIR, Cimel, MFRSR, GPS, and Vaisala RS92

At the Izaña Observatory, water vapour amounts have been measured routinely by different techniques for many years. We intercompare the total precipitable water vapour (PWV) amounts measured between 2005 and 2009 by a Fourier Transform Infrared (FTIR) spectrometer, a Multifilter Rotating Shadow-band Radiometer (MFRSR), a Cimel sunphotometer, a Global Positioning System (GPS) receiver, and daily radiosondes (Vaisala RS92). The long-term characteristics of our study allows a reliable and extensive empirical quality assessment of long-term validity, which is an important prerequisite when applying the data to climate research. We estimate a PWV precision of 1% for the FTIR, about 10% for the MFRSR, Cimel, and GPS (when excluding rather dry conditions), and significantly better than 15% for the RS92 (the detection of different airmasses avoids a better constrained estimation). We show that the MFRSR, Cimel and GPS data quality depends on the atmospheric conditions (humid or dry) and that the restriction to clear-sky observations introduces a significant dry bias in the FTIR and Cimel data. In addition, we intercompare the water vapour profiles measured by the FTIR and the Vaisala RS92, which allows the conclusion that both experiments are able to detect lower to upper tropospheric water vapour mixing ratios with a precision of better than 15%.The FTIR activities are supported by the European Commission and the Deutsche Forschungsgemeinschaft by funding via the projects SCOUT-O3 and GEOMON (contract SCOUT-O3-505390 and GEOMON-036677) and RISOTO (Geschaftszeichen SCHN 1126/1-1), respectively

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

Medida en tiempo cuasi-real y predicción a 24 h del contenido atmosférico de agua precipitable a partir de una red de receptores GPS en la isla de Tenerife

El uso como herramienta meteorológica del GPS está cada vez más extendido. Al contenido de vapor de agua integrado en la columna atmosférica se le denomina también agua precipitable, ya que, en caso de que este vapor condensara, y se dieran las condiciones necesarias, podría dar lugar a fenómenos de precipitación. Es un hecho constatado que el contenido de vapor de agua presente en la atmósfera influye en el retraso, debido a la refracción atmosférica, de la señal de radio enviada por la constelación de satélites transmisores GPS a su llegada a las antenas de los receptores situados en tierra. En el presente trabajo se pone a disposición del usuario información de utilidad de forma automática y en tiempo cuasi-real, basada en mapas y gráficos con valores medidos del contenido de agua precipitable (con un retraso aproximado de unas dos horas desde la realización de las medidas) así como de valores previstos a 24 horas basados en el modelo del Centro Europeo de Predicción a Plazo Medio sobre cada uno de los diferentes emplazamientos de las antenas GPS

Status of the Izaña BSRN Station

Póster presentado en: Twelfth BSRN Scientific Review and Workshop, celebrado del 1 al 3 de agosto de 2012 en Potsdam, Alemania.Financial supports from the Spanish MICIIN for projects CGL2009-09740, CGL2011-23413 and CGL2010-09480E, CGL2011-13085-E are gratefully acknowledged

Recovering long-term aerosol optical depth series (1976–2012) from an astronomical potassium-based resonance scattering spectrometer

A 37-year long-term series of monochromatic aerosol optical depth (AOD) has been recovered from solar irradiance measurements performed with the solar spectrometer Mark-I, deployed at Izaña mountain since 1976. The instrument operation is based on the method of resonant scattering, which affords wavelength absolute reference and stability (long-term stability and high precision) in comparison to other instruments based purely on interference filters. However, it has been specifically designed as a reference instrument for helioseismology, and its ability to determine AOD from transmitted and scattered monochromatic radiation at 769.9 nm inside a potassium vapour cell in the presence of a permanent magnetic field is evaluated in this paper. Particularly, the use of an exposed mirror arrangement to collect sunlight as well as the Sun–laboratory velocity dependence of the scattered component introduces some important inconveniences to overcome when we perform the instrument's calibration. We have solved this problem using a quasi-continuous Langley calibration technique and a refinement procedure to correct for calibration errors as well as for the fictitious diurnal cycle on AOD data. Our results showed similar calibration errors retrieved by means of this quasi-continuous Langley technique applied in different aerosol load events (from 0.04 to 0.3), provided aerosol concentration remains constant throughout the calibration interval.The AERONET sun photometers at Izaña have been calibrated within AERONET-Europe TNA supported by the European Community-Research Infrastructure Action under the FP7 “Capacities” specific programme for Integrating Activities, ACTRIS grant agreement no. 262254. The GAW-PFR network for AOD at WMO-GAW global observatories has been implemented by the World Optical Depth Research and Calibration Center (WORCC). Mark-I operation was supported by the Spanish National Plan of Research and Development under grant no. AYA2012–17803

Impacts of desert dust outbreaks on air quality in urban areas

Air pollution has many adverse effects on health and is associated with an increased risk of mortality. Desert dust outbreaks contribute directly to air pollution by increasing particulate matter concentrations. We investigated the influence of desert dust outbreaks on air quality in Santa Cruz de Tenerife, a city located in the dust export pathway off the west coast of North Africa, using air-quality observations from a six-year period (2012–2017). During winter intense dust outbreaks PM10 mean (24-h) concentrations increased from 14 µg m−3 to 98 µg m−3 , on average, and PM2.5 mean (24-h) concentrations increased from 6 µg m−3 to 32 µg m−3 . Increases were less during summer outbreaks, with a tripling of PM10 and PM2.5 daily mean concentrations. We found that desert dust outbreaks reduced the height of the marine boundary layer in our study area by >45%, on average, in summer and by ∼25%, on average, in winter. This thinning of the marine boundary layer was associated with an increase of local anthropogenic pollution during dust outbreaks. NO2 and NO mean concentrations more than doubled and even larger relative increases in black carbon were observed during the more intense summer dust outbreaks; increases also occurred during the winter outbreaks but were less than in summer. This has public health implications; local anthropogenic emissions need to be reduced even further in areas that are impacted by desert dust outbreaks to reduce adverse health effects.This activity has been undertaken in the framework of the World Meteorological Organisation Global Atmosphere Watch Urban Research Meteorology and Environment (GURME) project