Study of the relative humidity dependence of aerosol light-scattering in southern Spain

This investigation focuses on the characterisation of the aerosol particle hygroscopicity. Aerosol particle optical properties were measured at Granada, Spain, during winter and spring seasons in 2013. Measured optical properties included particle light-absorption coefficient (σap) and particle light-scattering coefficient (σsp) at dry conditions and at relative humidity (RH) of 85±10%. The scattering enhancement factor, f(RH=85%), had a mean value of 1.5±0.2 and 1.6±0.3 for winter and spring campaigns, respectively. Cases of high scattering enhancement were more frequent during the spring campaign with 27% of the f(RH=85%) values above 1.8, while during the winter campaign only 8% of the data were above 1.8. A Saharan dust event (SDE), which occurred during the spring campaign, was characterised by a predominance of large particles with low hygroscopicity. For the day when the SDE was more intense, a mean daily value of f(RH=85%)=1.3±0.2 was calculated. f(RH=85%) diurnal cycle showed two minima during the morning and afternoon traffic rush hours due to the increase in non-hygroscopic particles such as black carbon and road dust. This was confirmed by small values of the single-scattering albedo and the scattering Ångstrom exponent. A significant correlation between f(RH=85%) and the fraction of particulate organic matter and sulphate was obtained. Finally, the impact of ambient RH in the aerosol radiative forcing was found to be very small due to the low ambient RH. For high RH values, the hygroscopic effect should be taken into account since the aerosol forcing efficiency changed from −13 W/m2 at dry conditions to −17 W/m2 at RH=85%

Saharan and arabian dust aerosols: a comparative case study of lidar ratio

El volumen 119 de 2016 de la revista EPJ Web of Conferences recoge las ponencias del 27th International Laser Radar Conference (ILRC 27)This work presents a first comparative study of the Lidar Ratio (LR) values obtained for dust particles in two singular dust-influenced regions: the Canary Islands (Spain, close to the African coast in the North Atlantic Ocean), frequently affected by Saharan dust intrusions, and the Kuwait area (Arabian Peninsula) as usually influenced by Arabian dust storms. Synergetic lidar and sun-photometry measurements are carried out in two stations located in these particular regions for that purpose. Several dusty cases were observed during 2014 in both stations and, just for illustration, two specific dusty case studies have been selected and analyzed to be shown in this work. In general, mean LR values of 54 sr and 40 sr were obtained in these studies cases for Saharan and Arabian dust particles, respectively. Indeed, these results are in agreement with other studies performed for dust particles arriving from similar desert areas. In particular, the disparity found in Saharan and Arabian dust LR values can be based on the singular composition of the suspended dust aerosols over each station. These results can be useful for CALIPSO extinction retrievals, where a single LR value (40 sr) is assumed for pure dust particles independently on the dust source region.This work has been supported by both the Spanish Ministerio de Economía y Competitividad (MINECO) under grant CGL2011-24891 (AMISOC project) and the Kuwait Foundation for the Advancement of Sciences under project 2011- 1401-01

Vertical mass impact and features of Saharan dust intrusions derived from ground-based remote sensing in synergy with airborne in-situ measurements

A study of the vertical mass impact of Saharan dust intrusions is presented in this work. Simultaneous ground-based remote-sensing and airborne in-situ measurements performed during the AMISOC-TNF campaign over the Tenerife area (Canary Islands) in summertime from 01 July to 11 August 2013 were used for that purpose. A particular dusty (DD) case, associated to a progressively arriving dust intrusion lasting for two days on 31 July (weak incidence) and 01 August (strong incidence), is especially investigated. AERONET AOD and AEx values were ranging, respectively, from 0.2 to 1.4 and 0.35 to 0.05 along these two days. Vertical particle size distributions within fine and coarse modes (0.16e2.8 mm range) were obtained from aircraft aerosol spectrometer measurements. Extinction profiles and Lidar Ratio (LR) values were derived from MPLNET/Micro Pulse Lidar observations. MAXDOAS measurements were also used to retrieve the height-resolved aerosol extinction for evaluation purposes in comparison to Lidarderived profiles.This work is supported by the Spanish Ministerio de Economía y Competitividad (MINECO) under grants CGL2011-24891 and CGL2014-55230-R

The Spanish Network on Environmental DMAs: introduction and main activities

Comunicación presentada en: V Reunión Española de Ciencia y Tecnología de Aerosoles – RECTA 2011 celebrada del 27 al 29 de junio de 2011 en CIEMAT, Madrid

La radiación solar: efectos en la salud y el medio ambiente

140 páginasEl incremento de cierto tipo de radiaciones ultravioletas procedentes del sol, perjudiciales para la salud y el medio ambiente es un tema de candente actualidad, a pesar de la aparente recuperación de la capa de ozono, filtro protector de la biosfera y de la calidad de vida de los seres que habitan el Planeta. La obra ha tratado de definir la situación actual de este gas a escala planetaria, analizando las causas físicas de su aparición y de su destrucción y las consecuencias que para el medio ambiente y la salud tiene el incremento de radiación ultravioleta

Synergetic monitoring of Saharan dust plumes and potential impact on surface: a case study of dust transport from Canary Islands to Iberian Peninsula

The synergetic use of meteorological information, remote sensing both ground-based active (lidar) and passive (sun-photometry) techniques together with backtrajectory analysis and in-situ measurements is devoted to the characterization of dust intrusions. A case study of air masses advected from the Saharan region to the Canary Islands and the Iberian Peninsula, located relatively close and far away from the dust sources, respectively, was considered for this purpose. The observations were performed over three Spanish geographically strategic stations within the dust-influenced area along a common dust plume pathway monitored from 11 to 19 of March 2008. A 4-day long dust event (13–16 March) over the Santa Cruz de Tenerife Observatory (SCO), and a linked short 1-day dust episode (14 March) in the Southern Iberian Peninsula over the Atmospheric Sounding Station "El Arenosillo" (ARN) and the Granada station (GRA) were detected.This work has been supported by the Spanish Ministry for Science and Innovation (MICINN) under the Complementary Actions CGL2008-01330-E (2009) in the frame of the Spanish and Portuguese Aerosol LIdar NETwork (SPALINET), and CGL2010-10012-E (Evaluation of lidar observations in the frame of CIEMAT/EARLINET intercomparison by airborne in-situ measurements of trace gases and aerosols, MISPA-LIDAR, 2010); projects CGL2008-05939-C03-03/CLI, CGL2007-66477-C02-01, CSD2007-00067 and CGL2010-18782 of the Spanish Ministry of Education; projects P08-RNM-3568 and P10-RNM-6299 of the Autonomous Government of Andalusia; and the EARLINET-ASOS project (EU Coordination Action, contract no. 025991 (RICA)). JLG-R thanks the Spanish Ministry of Education and the Portuguese Fundaçao para a Ciencia e a Tecnologia for supporting under grants EX2009-0700 and SFRH/BPD/63090/2009, respectively

Calibration and intercomparison results in the Spanish network on environmental DMAs

Comunicación presentada en: 2012 European Aerosol Conference (EAC-2012), B-WG01S2P30, celebrada del 2 al 7 de septiembre de 2012 en Granada.This network is financed by the Ministry of Science and Innovation (CGL2011-15008-E)

The REDMAAS 2012 SMPS+UFP intercomparison campaign

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.This network is financed by the Ministry of Science and Innovation (CGL2011-15008-E & CGL2011-27020)

The REDMAAS 2014 intercomparison campaign: CPC, SMPS, UFPM and neutralizers

Ponencia presentada en:2nd Iberian Meeting on Aerosol Science and Technology (RICTA 2014) celebrado en Tarragona del 7 al 9 de julio de 2014.The Spanish network on environmental DMAs (Red Española de DMAs Ambientales, REDMAAS), working since 2010, is currently formed by six groups involved in the measurement of atmospheric aerosol size distributions by means of Differential Mobility Analyzers (DMAs). One of its activities is an annual intercomparison of mobility size spectrometers (SMPS and UFPM). In this work we show the results obtained in the 2014 campaign: the verification of DMA calibrations with latex, the results of the CPC and SMPS + UFPM intercomparisons, and a comparison of the new TSI 3087 X-ray and the former TSI 3077 85Kr neutralizers. The concentrations measured by different types of CPC were within the range of 10% of the average value. CPCs working at higher flow rates measured slightly higher concentrations, probably related to the smaller losses in the lines. All the SMPS worked at the same sampling and sheath flow rates (1:10 lpm). Four of the SMPS gave very good results for particles larger than 20 nm. The UFPM measured particle number concentrations in the average +/-10% band measured by the SMPS. Instruments working with the X-ray neutralizer measured higher concentrations than with the 85Kr neutralizers. This could mean that particle losses are smaller inside this neutralizer.This work has been financed by the Ministry of Science and Innovation (CGL2011-15008-E, CGL2010-1777, CGL2011-27020 & CGL2011-26259)

Atmospheric particle size distributions in the Spanish Network of Environmental DMAs (REDMAAS)

The present work is a first approach to the study of the spatio-temporal variability of the submicrometer atmospheric aerosol in Spain. The aerosol measurements have been obtained simultaneously at seven monitoring stations that compose the REDMAAS network during two measurement campaigns corresponding to summer and winter seasons. In both summer and winter periods those measurement stations with a direct influence of anthropogenic emissions recorded the highest concentrations of particle number. In the summer campaign, the average daily pattern of the aerosol size distribution in the traffic and background urban stations was conditioned by the traffic emissions and secondary aerosol formation through photochemical reactions (new particle formation events, NPF). However, the secondary aerosol had a higher contribution to the aerosol total number concentration in the rural background and high-altitude stations. In the winter campaign, in all sampling sites with the exception of Izaña station, the traffic and domestic activity emissions had a greater contribution than secondary aerosol formation on particle number total concentration. New particle formation events were identified at all sites during the summer period, and at sites without direct influence of anthropogenic emissions during the winter campaign. Some aerosol shrinkage processes were also observed at the Madrid and El Arenosillo stations.This work has been financed by the Ministry of Science and Innovation (CGL2011-15008-E, CGL2010-1777, CGL2011-27020, CGL2014-52877-R & CGL2014-55230-R), Xunta de Galicia (GRC2013-047 potentially cofounded by ERDF) and the European Union Seventh Framework Programme (FP7/2007–2013) ACTRIS under grant agreement no. 262254