Irradiación solar ultravioleta eritemática en Valencia durante el año 2000

Ponencia presentada en: II Congreso de la Asociación Española de Climatología “El tiempo del clima”, celebrado en Valencia del 7 al 9 de junio de 2001[ES]Se ha estudiado el comportamiento de la radiación solar ultravioleta eritemática integrada recibida sobre una superficie horizontal y correspondiente a Valencia durante el año 2000. En dicho estudio se han considerado los índices estadísticos más representativos como son la media aritmética (M), la mediana (Md), la desviación estándar (DE) y los valores máximo (Mx) y mínimo (Mn). Se han considerado valores de irradiación semihoraria y diaria obtenidos a partir de registros continuos de irradiancia. También se han analizado los valores acumulados a lo largo de un día para diferentes meses y para todo el año.[EN]Experimental data concerning the integrated erythematic ultraviolet radiation on a horizontal surface measured at Valencia during the year 2000 have been analysed. A study of the most representative statistical indexes: arithmetic mean (M), median (Mn), standard deviation (DE), maximum (Mx) and minimum (Mn) values has been carried out. The study has focused on both the half hourly and daily values of the solar ultraviolet irradiation. The accumulated values a long a da y and through a whole year have also been considered.Este trabajo ha sido realizado con financiación de la Comisión Interministerial de Ciencia y Tecnología (CICYT) a través de los Proyectos Coordinados CLI97-0345-C05 y REN2000-0903-COSCLI

Comparación de modelos simples para el estudio de la radiación eritemática global sobre planos inclinados

Ponencia presentada en: XXX Jornadas Científicas de la AME y el IX Encuentro Hispano Luso de Meteorología celebrado en Zaragoza, del 5 al 7 de mayo de 2008

Column-integrated aerosol optical properties in Sodankylä (Finland) during the Solar Induced Fluorescence Experiment (SIFLEX-2002).

A study has been made of the column aerosols using solar irradiance extinction measurements at ground level in a boreal region (Sodankyla ̈, Finland) during spring 2002. The aerosol properties have been related to air mass origin. In general, the aerosol levels were observed to be very low, independent of the air mass origin, with an aerosol optical depth (AOD) value at 500 nm of less than 0.09 ± 0.03. Two characteristic patterns were observed depending on whether the air masses originated in the north and west or from the south and east. In the first case (north and west origins) the aerosol load was very small, with very low optical depths in the range 0.03 ± 0.02 to 0.09 ± 0.03 for 500 nm wavelengths. The size distribution usually showed two modes, with a strong contribution from the large-particle mode, probably a consequence of the presence of maritime-type particles originating in the ocean. When the air masses originated from a south or east direction, the behavior was the opposite to that noted before. In these cases the AOD was rather larger, above all for air masses originating in central Europe and Russia with an average value at 500 nm of 0.14 ± 0.02

Aerosol radiative forcing efficiency in the UV region over southeastern Mediterranean: VELETA2002 campaign

Atmospheric aerosol effects on spectral global UV irradiance were evaluated during the VELETA2002 field campaign between 8 and 19 July 2002 in southeast Spain. In the first stage, seven UV spectroradiometer and six CIMEL Sun photometer measurements were carried out simultaneously, allowing them to be calibrated and intercompared. The mean ratio obtained for the global irradiance between the spectroradiometers, with regards to a reference instrument, ranges from 0.98 up to 1.04 with standard deviations that oscillate between ±0.01 and ±0.17. In particular, the two spectroradiometers used to obtain the aerosol forcing efficiencies have a ratio of 1.000 ± 0.001. The aerosol optical depth (AOD) obtained with the CIMEL Sun photometers has a standard deviation of lower than ±0.01 for all the channels. Under clear sky conditions, the diurnal aerosol forcing efficiency (DDFe) and fractional diurnal forcing efficiency (DFDFe) was calculated for two Mediterranean stations: Armilla (691 m.a.s.l.) within the boundary layer and Sabinas (2200 m.a.s.l) on the lower limit of the free troposphere and 25 km away from the first station. The DDFe values obtained at Armilla range between _2.72 ± 0.45 W m_2/t380 and _2.88 ± 0.45 W m_2/t440 and between _3.22 ± 0.61 W m_2/t380 and _3.40 ± 0.62 W m_2/t440 at Sabinas station; the DFDFe values range from _8.0 ± 1.4%/t380 to _8.6 ± 1.3%/t440 and _12.0 ± 2.3%/t380 to _12.6 ± 2.3%/t440 at the two stations, respectively. Also, an experimental aerosol transmittance factor, CT, used to obtain UV satellite derived products was found as a result of the dependence of the global irradiance with the AOD, under cloudless conditions. The average aerosol attenuation factor, h, obtained from the CT, is 6 ± 2% under weakly absorbing aerosols, with a negligible spectral dependence.This work was supported by CICYT–MCYT through the coordinated projects CGL2004-05984-C07-05 and CGL2005-03428-C04-02

Extreme, wintertime Saharan dust intrusion in the Iberian Peninsula: Lidar monitoring and evaluation of dust forecast models during the February 2017 event

The research leading to these results has received funding from the H2020 program from the European Union (grant agreement no. 654109, 778349) and also from the Spanish Ministry of Industry, Economy and Competitiviness (MINECO, ref. CGL2013-45410-R, CGL2016-81092-R, CGL2017-85344-R, TEC2015-63832-P), the Spanish Ministry of Science, Innovation and Universities (ref. CGL2017-90884-REDT); the CommSensLab "Maria de Maeztu" Unity of Excellence (ref. MDM-2016-0600) financed by the Spanish Agencia Estatal de Investigación. Co-funding was also provided by the European Union through the European Regional Development Fund (ref. POCI-01-0145-FEDER-007690, ALT20-03-0145-FEDER-000004, ALT20-03-0145-FEDER-000011); by the Andalusia Regional Government (ref. P12-RNM-2409); by the Madrid Regional Government (projects TIGAS-CM, ref. Y2018/EMT-5177 and AIRTEC-CM, ref. P2018/EMT4329); by the University of Granada through “Plan Propio. Programa 9 Convocatoria 2013” and by the Portuguese Foundation for Science and Technology and national funding (ref. SFRH/BSAB/143164/2019). The BSC-DREAM8b and NNMB/BSC-Dust (now NMMB-MONARCH) model simulations were performed by the Mare Nostrum supercomputer hosted by the Barcelona Supercomputer Center (BSC). S. Basart acknowledges the AXA Research Fund for supporting aerosol research at the BSC through the AXA Chair on Sand and Dust Storms Fund, as well as the InDust project (COST Action CA16202). The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (http://www.ready.noaa.gov) used in this publication.An unprecedented extreme Saharan dust event was registered in winter time from 20 to 23 February 2017 over the Iberian Peninsula (IP). We report on aerosol optical properties observed under this extreme dust intrusion through passive and active remote sensing techniques. For that, AERONET (AErosol RObotic NETwork) and EARLINET (European Aerosol Research LIdar NETwork) databases are used. The sites considered are: Barcelona (41.38°N, 2.17°E), Burjassot (39.51°N, 0.42°W), Cabo da Roca (38.78°N, 9.50°W), Évora (38.57°N, 7.91°W), Granada (37.16°N, 3.61°W) and Madrid (40.45°N, 3.72°W). Large aerosol optical depths (AOD) and low Ångström exponents (AE) are observed. An AOD of 2.0 at 675 nm is reached in several stations. A maximum peak of 2.5 is registered in Évora. During and around the peak of AOD, AEs close to 0 and even slightly negative are measured. With regard to vertically-resolved aerosol optical properties, particle backscatter coefficients as high as 15 Mm−1 sr−1 at 355 nm are recorded at the lidar stations. Layer-mean lidar ratios are found in the range 40–55 sr at 355 nm and 34–61 sr at 532 nm during the event. The particle depolarization ratios are found to be constant inside the dust layer, and consistent from one site to another. Layer-mean values vary in the range 0.19–0.31. Another remarkable aspect of the event is the limited vertical distribution of the dust plume which never exceeds 5 km. The extreme aspect of the event also presented a nice case for testing the ability of two dust forecast models, BSC-DREAM8b and NMMB/BSC-Dust, to reproduce the arrival, the vertical distribution and the intensity of the dust plume over a long-range transport region. In the particular case of the February 2017 dust event, we found a large underestimation in the forecast of the extinction coefficient provided by BSC-DREAM8b at all heights independently of the site. In contrast NMMB/BSC-Dust forecasts presented a better agreement with the observations, especially in southwestern part of the IP. With regard to the forecast skill as a function of lead time, no clear degradation of the prognostic is appreciated at 24, 48 and 72 h for Évora and Granada stations (South). However the prognostic does degrade (bias increases and/or correlation decreases) for Barcelona (North), which is attributed to the fact that Barcelona is at a greater distance from the source region and to the singularity of the event.Funding from the H2020 program from the European Union (grant agreement no. 654109, 778349)Spanish Ministry of Industry, Economy and Competitiviness (MINECO, ref. CGL2013-45410-R, CGL2016-81092-R, CGL2017-85344-R, TEC2015-63832-P)Spanish Ministry of Science, Innovation and Universities (ref. CGL2017-90884-REDT)CommSensLab "Maria de Maeztu" Unity of Excellence (ref. MDM-2016-0600) financed by the Spanish Agencia Estatal de InvestigaciónCo-funding was also provided by the European Union through the European Regional Development Fund (ref. POCI-01-0145-FEDER-007690, ALT20-03-0145-FEDER-000004, ALT20-03-0145-FEDER-000011)Andalusia Regional Government (ref. P12-RNM-2409); by the Madrid Regional Government (projects TIGAS-CM, ref. Y2018/EMT-5177 and AIRTEC-CM, ref. P2018/EMT4329)Portuguese Foundation for Science and Technology and national funding (ref. SFRH/BSAB/143164/2019

Diffuse and Direct UV Index Experimental Values

In this work, we study the different components of the UV Index, direct, diffuse, and global, for seven years of UV erythemal measurements in a Mediterranean locality at Burjassot AtmoSpheric Station (BASS). The measurements have been taken with three YES-UVB-1 radiometers: one provided with a shadow disk on a Sun tracker; a radiometer to measure the global horizontal radiation; and a Sun-tracking radiometer to measure the direct radiation with an especially designed radiance collimator. It is known that diffuse UV irradiance represents at least 50% of total UV irradiance on a horizontal plane, which means being able to obtain a high UV Index even under shade. Our study aims to establish the relationship between the UV Index at noon and the maximum daily UV erythemal irradiance in the mid-latitude area, as well as the potential erythemal effects of exposure to solar UV radiation on different skin phototypes (skin phototypes I–IV) for both direct and diffuse components

El índice UV sobre planos inclinados

Ponencia presentada en: XXIX Jornadas Científicas de la AME y el VII Encuentro Hispano Luso de Meteorología celebrado en Pamplona, del 24 al 26 de abril de 2006

Operational considerations to improve total ozone measurements with a Microtops II ozone monitor [Discussion paper]

A Microtops II “ozone monitor” with UV channels centered at 305.5, 312.5, and 320 nm has been used routinely in six experimental campaigns carried out in several geographic locations and seasons, covering latitudes from 35 to 68◦ N during the last ten years (2001–2011). The total ozone content is retrieved by Microtops II by using different combinations (Channel I, 305.5/312.5 nm; Channel II, 312.5/320 nm; and Channel III, 305.5/312.5/320 nm) of the signals at the three ultraviolet wavelengths. When a calibration was used and the airmass limit was fixed to 3, Microtops II produce mean relative deviations with respect to the Brewer of 0.1, −11, and 8 % respectively for the Channel I, Channel II, and Channel III retrieval. The performance of the Microtops retrieval has been stable during the last ten years. Channel I represents the best option to determine the instantaneous total ozone content. Channel II and III values appear weakly sensitive to temperature, ozone content, and aerosols. Channel II is more stable than Channel I for airmasses larger than 2.6. The conclusions do not show any dependence on latitude and season.This study was possible thanks to a postdoctoral fellowship funded by the Generalitat Valenciana in the case of J. L. Gomez Amo (in the framework of “Estancies post- doctorals en centres de Excellencia de la Comunitat Valenciana” programme) and a Juan de la Cierva research contract (JCI-2009-04455) in the case of V. Estellés, funded by the Spanish Ministry of Science and Innovation (MICINN). This work was also supported by the MICINN projects CGL2007-60648 and CGL2009-07790, and by the Valencian Autonomous Government through the Project PROMETEO/2010/064

Intercomparison of spectroradiometers for global and direct solar irradiance in the visible range.

This paper presents the results of the analysis of the spectral, global, and direct solar irradiance measurements in the visible range (400700 nm) that were made in the framework of the first Iberian UVvisible (VIS) instruments intercomparison. The instruments used in this spectral range were four spectroradiometers: three Licor 1800s equipped with different receiver optics and one Optronic 754. For the direct solar irradiance measurements the spectroradiometers were equipped with collimators with different fields of view. Parallel studies have been carried out with the data given by the spectroradiometers with their original calibration file and with the same data that is corrected, following in situ calibration of the instruments using a laboratory reference lamp. To compare the series of spectral data the relative values of mean absolute deviation (MAD) and root-mean-square deviation (rmsd) have been used. The results obtained from the measurements of global irradiance show that the Licor 1800s presented very significant differences at the beginning and at the end of the day due to the deviation from ideal cosine response of the collection optics (i.e., cosine errors). This forced the analysis to be limited to the measurements corresponding to solar elevations higher than 30°. For this solar elevation range, the results of the intercomparison between the Licor instruments, before their in situ calibration, showed differences of about 5% in the visible range. The results from the measurements of direct irradiance show that, if correction factors are considered, these deviations are reduced to 3%, and when the Licors are compared with the Optronic, the deviations are less than 2%