Extreme Saharan dust event over the southern Iberian Peninsula in september 2007: active and passive remote sensing from surface and satellite 1Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Granada, Fuentenueva s/n, 18071, Granada, Spain
2Centro Andaluz de Medio Ambiente (CEAMA), Junta de Andalucía-Universidad de Granada, Av. del Mediterráneo s/n, 18071, Granada, Spain
Received: 14 Apr 2009 – Published in Atmos. Chem. Phys. Discuss.: 24 Jul 2009 Abstract. This study investigates aerosol optical properties during the extreme
Saharan dust event detected from 3 to 7 September 2007 over Granada,
southern Iberian Peninsula, with both active and passive remote sensing
instrumentation from surface and satellite. The intensity of the event was
visualized on the aerosol optical depth series obtained by the
sun-photometer Cimel CE 318-4 operated at Granada in the framework of
AERONET from August 2004 until December 2008 (level 2 data). A combination
of large aerosol optical depth (0.86–1.50) at 500 nm, and reduced
Angström exponent (0.1–0.25) in the range 440–870 nm, was detected on 6
September during daytime. This Saharan dust event also affected other
Iberian Peninsula stations included in AERONET (El Arenosillo and Évora
stations), and it was monitored by MODIS instrument on board Aqua satellite.
Vertically resolved measurements were performed by a ground-based Raman
Lidar and by CALIPSO satellite. During the most intense stage, on 6
September, maximum aerosol backscatter values were a factor of 8 higher than
other maxima during this Saharan dust event. Values up to
sr−1 at 355 and 532 nm were detected in the layer
with the greatest aerosol load between 3–4 km a.s.l., although aerosol
particles were also detected up to 5.5 km a.s.l. In this stage of the event,
dust particles at these altitudes showed a backscatter-related Angström
exponent between –0.44 and 0.53 for the two spectral intervals considered.
The results from different measurements (active/passive and
ground-based/satellite) reveal the importance of performing
multi-instrumental measurements to properly characterize the contribution of
different aerosol types from different sources during extreme events. The
atmospheric stabilization effect of the aerosol particles has been
characterized by computing the solar heating rates using SBDART code.
Revised: 15 Oct 2009 – Accepted: 19 Oct 2009 – Published: 06 Nov 2009
Citation: Guerrero-Rascado, J. L., Olmo, F. J., Avilés-Rodríguez, I., Navas-Guzmán, F., Pérez-Ramírez, D., Lyamani, H., and Alados Arboledas, L.: Extreme Saharan dust event over the southern Iberian Peninsula in september 2007: active and passive remote sensing from surface and satellite, Atmos. Chem. Phys., 9, 8453-8469, doi:10.5194/acp-9-8453-2009, 2009.