@misc{10481/47093,
year = {2014},
url = {http://hdl.handle.net/10481/47093},
abstract = {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 (sap) and particle light-scattering coefficient (ssp) 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 Angstrom 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 -13W/m2 at dry conditions to -17W/m2 at RH=85%.},
organization = {This work was supported by the Andalusia Regional Government through projects P10-RNM-6299 and P12-RNM-2409; by the Spanish Ministry of Economy and Competitiveness through projects CGL2010-18782, CSD2007-00067, CGL2011-13580-E/CLI and CGL2011-16124-E; and by EU through ACTRIS project (EU INFRA-2010-1.1.16-262254).},
organization = {G. Titos was funded by the program FPI of the Spanish Ministry of Economy and Competitiveness – Secretariat of Science, Innovation and Development under grant BES-2011-043721.},
publisher = {Taylor and Francis},
keywords = {Aerosol particle light scattering},
keywords = {Hygroscopic growth},
keywords = {Scattering enhancement},
keywords = {Radiative forcing},
keywords = {Field measurements},
title = {Study of the relative humidity dependence of aerosol light-scattering in southern Spain},
doi = {10.3402/tellusb.v66.24536},
author = {Titos Vela, Gloria and Lyamani, H. and Cazorla Cabrera, Alberto and Sorribas, M. and Foyo Moreno, Inmaculada and Wiedensohler, A. and Alados Arboledas, Lucas},
}