A long Saharan dust event over the western Mediterranean: Lidar, Sun photometer observations, and regional dust modeling

Abstract

[1] A long Saharan dust event affected the western Mediterranean in the period 12-28 June 2002. Dust was present mainly between 1-and 5-km height affecting most parts of the Iberian Peninsula and reaching western/central Europe. Intensive backscatter lidar observations over Barcelona (Spain) and Sun photometer data from two stations (El Arenosillo, Spain, and Avignon, France) are used to evaluate different configurations the Dust Regional Atmospheric Modeling (DREAM) system. DREAM currently operates dust forecasts over the Mediterranean region (http://www.bsc.es/projects/earthscience/ DREAM/) considering four particle size bins while only the first two are relevant for long-range transport analysis since their life time is larger than 12 hours. A more detailed bin method is implemented, and two different dust distributions at sources are compared to the operational version. Evaluations are performed at two wavelengths (532 and 1064 nm). The dust horizontal and vertical structure simulated by DREAM shows very good qualitative agreement when compared to SeaWIFS satellite images and lidar height-time displays over Barcelona. When evaluating the modeled aerosol optical depth (AOD) against Sun photometer data, significant improvements are achieved with the use of the new detailed bin method. In general, the model underpredicts the AOD for increasing Å ngström exponents because of the influence of anthropogenic pollution in the boundary layer. In fact, the modeled AOD is highly anticorrelated with the observed Å ngström exponents. Avignon shows higher influence of small anthropogenic aerosols which explains the better results of the model at the wavelength of 1064 nm over this location. The uncertainties of backscatter lidar inversions (20-30%) are in the same order of magnitude as the differences between the model experiments. Better model results are obtained when comparing to lidar because most of the anthropogenic effect is removed.Citation: Pérez, C., S. Nickovic, J. M. Baldasano, M. Sicard, F. Rocadenbosch, and V. E. Cachorro (2006), A long Saharan dust event over the western Mediterranean: Lidar, Sun photometer observations, and regional dust modeling,

Assesment of PM10 pollution episodes in a ceramic cluster (NE Spain): Proposal of a new quality index for PM10, As, Cd, Ni and Pb

“…The origin of PM10 in this area is both natural and anthropogenic. The former is due to the resuspension of mineral materials from the surrounding mountains with poor vegetation coverage and the long-range transport of materials from North Africa (Rodríguez et al 2001, Pérez et al 2006. These dust intrusions from North Africa influence ambient PM10 levels in the study area at around 2 !/m 3 on an annual basis (Minguillón et al, 2009).…”

Air pollution prediction models of particles, As, Cd, Ni and Pb in a highly industrialized area in Castellón (NE, Spain)

“…The natural origin is due to the resuspension of mineral materials from the surrounding mountains (Gómez et al 2004) and from the long-range transport of materials from North Africa (Rodríguez et al 2004, Pérez et al 2006 The anthropogenic pollution sources (Fig. 2) are the traffic (mobile sources), and also originate from the manufacturers of ceramic tiles and raw material as frits, enamel and ceramic colours (fixed sources) (Sanfeliu et al 2002.…”

Assessment and validation in time domain of a Robust Satellite Technique (RSTASH) for ash cloud detection

“…Ackerman 1997, Legrand et al 2001, Webley et al 2009). Therefore, in order to verify if dust clouds were the cause of major RST ASH misdetections, the outputs of the Dust Regional Atmospheric Model (DREAM), designed to simulate and/or predict the 3-dimensional field of the dust concentration in the troposphere (see Nickovic et al 2001 andPerez et al 2006, for details) were used. In particular, 6-hour forecasts of the horizontal distribution of the dust loading provided by DREAM over the Mediterranean region were examined.…”