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- The strongest desert dust intrusion mixed with smoke over the Iberian Peninsula registered with Sun photometryPublication . Cachorro, Victoria; Toledano, C.; Prats, N.; Sorribas, Mar; Mogo, Sandra; Berjón, Alberto Jesús; Torres, B.; Rodrigo, R.; de la Rosa, Jesús D; De Frutos, Ángel MWe present the analysis of the strongest North African desert dust (DD) intrusion that occurred over the Iberian Peninsula (IP) during the last decade, as registered by modern remote sensing techniques like Sun photometry. This event took place from 22 July to 3 August 2004. The most relevant features of this exceptional event, originated over the Saharan desert, were its great intensity and duration. We focus on the columnar aerosol properties measured by the AERONET-Cimel photometers at El Arenosillo (southwest) and Palencia (north-center) stations. Aerosol optical depth (AOD) reached a maximum of 2.7 at El Arenosillo during 22 July and 1.3 at Palencia on 23 July, with the Ånsgtröm exponent values near zero during the AOD peaks. In addition, PM10 concentration levels are also reported at various sites of the IP in order to establish the impact of this intrusion, reaching daily values as high as 200 mg/m3 and peaks near 600 mg/m3 in an hourly basis. The interest of this special event is increased because of the mixing with smoke particles from concurrent forest fires in the IP. Features of the columnar volume particle size distribution and derived microphysical parameters, the single scattering albedo, and a reliable estimation of the radiative forcing under these extreme conditions are also reported. Complementary information, as air mass back trajectories, synoptic charts, images, and AOD maps of satellite sensors (SeaWIFS, MODIS) together with NAAPS prognostic model, is used in the analysis in order to draw a detailed scenario of this dust-smoke event over the IP.
- Columnar aerosol optical properties during “El Arenosillo 2004 summer campaign”Publication . Prats, Natalia; Cachorro, Victoria; Sorribas, M.; Mogo, Sandra; Berjón, Alberto Jesús; Toledano, Carlos; De Frutos, Ángel M; de la Rosa, Jesús D; Laulainen, Nels S.; de la Morena, Benito ArturoA detailed analysis of the columnar optical aerosol properties has been carried out for data collected during the ‘‘El Arenosillo 2004 summer campaign’’. These data are derived from a Cimel sun-photometer, as part of the PHOTONS-AERONET network at the El Arenosillo site in south-western Spain, over the period 1 June to 31 October 2004. Version 1 AERONET inversion products are used in the analysis. The aim of this campaign was to obtain a more complete set of data on aerosol particle microphysical, optical/radiative, absorbing and chemical properties for use in closure studies. In his paper we focus on the characterization of the aerosol optical depth (AOD)–alpha coefficients, and the particle size distribution together with their associated microphysical parameters, such as volume concentration, effective radius, etc., in order to define the features and ranges of these physical parameters associated with both fine and coarse particle modes. The requirement of high AOD values for using the inversion technique puts significant constraints on the estimation of the single scattering albedo (SSA) and refractive index, and thus requires great care in the analysis. As a result, only the characterizations of these parameters for desert dust events are considered reliable. Moreover, summer 2004 had the most frequent desert dust intrusions, including the most intense event (22–28 July and 31 July–2 August) ever recorded at the El Arenosillo site since the start of the measurements in February 2000. We summarize the results for the intensive summer campaign in terms of the range of values of the physical and optical parameters of the different aerosol types present in this area of Spain.
- Comparing surface measurement of black carbon and columnar AERONET inferred contents during the “El Arenosillo 2004 summer campaignPublication . Mogo, Sandra; Cachorro, Victoria; De Frutos, Ángel M; De La Rosa, Jesús D; Sorribas, MarDuring the summer of 2004 a field campaign was carried out at the El Arenosillo Atmospheric Sounding Station (ESAt), near Huelva, South-Western Spain. The campaign was designed to obtain experimental data on aerosol in situ absorption, size distribution, chemical composition, and columnar optical properties but this paper deals only with the evaluation of the absorbent aerosol. A Dekati cascade impactor and a PM10 Graseby-Andersen high volume sampler were used to collect aerosol fractions over filters. In this paper an estimation is made for the concentration of black carbon at ground level, using the absorption coefficients obtained from a filter transmission method. The values obtained are highly variable and range from 31 ng m-3 to 770 ng m-3. The high volume sampler filters were analyzed for elemental carbon with a thermal- optical method (LECO). The black carbon concentration is also compared with the columnar level retrieved from aerosol absorption optical depth derived from inversion of a sun-photometer data inside the AERONET framework.