H Wex et al 2008 Environ. Res. Lett. 3 035004 doi:10.1088/1748-9326/3/3/035004
H Wex1, F Stratmann1, T Hennig1,2, S Hartmann1, D Niedermeier1, E Nilsson1,3, R Ocskay4, D Rose5, I Salma4 and M Ziese1
Show affiliationsPart of Focus on Aerosol-Cloud Interactions
This work recompiles studies that have been done with respect to hygroscopic growth in the regime of high relative humidities and with respect to activation for different kinds of particle at LACIS (Leipzig Aerosol Cloud Interaction Simulator) during the last few years. The particles examined consisted of a mixture of succinic acid and ammonium sulfate, seawater samples, soot coated with an organic and/or an inorganic substance, and two different atmospheric HULIS (HUmic LIke Substance) samples. An influence of changing non-ideal behavior and of slightly soluble substances on the hygroscopic growth was found in varying degrees in the subsaturation regime. The measured hygroscopic growth was extrapolated towards supersaturation, using a simple form of the Köhler equation, and assuming a constant number of molecules/ions in solution for high relative humidities (≥95% or ≥98%, depending on the particles). When the surface tension of water was used, the modeled critical supersaturations reproduced the measured ones for the seawater samples and for the coated soot particles. To reach agreement between measured and modeled critical supersaturations for the HULIS particles, a concentration-dependent surface tension had to be used, with values of the surface tension that were lower than that of water, but larger than those that had been reported for bulk measurements in the past.
92.60.Mt Particles and aerosols
92.60.Jq Water in the atmosphere (humidity, clouds, evaporation, precipitation)
Issue 3 (July-September 2008)
Received 7 May 2008, accepted for publication 30 June 2008
Published 24 July 2008
H Wex et al 2008 Environ. Res. Lett. 3 035004
Srdjan Ostojic and Debabrata Panja J. Stat. Mech. (2005) P01011
Helmut Rechenberg 2001 Eur. J. Phys. 22 441
O Sardan et al 2008 Nanotechnology 19 495503
C Bottrill et al 2010 Environ. Res. Lett. 5 014019
S H Chen et al 1994 J. Phys.: Condens. Matter 6 10855
T. Aste et al 2007 EPL 79 24003
Mingzhen Tang et al 2007 Nanotechnology 18 485304
J Roth 1993 J. Phys. A: Math. Gen. 26 1455
E Narevicius et al 2007 New J. Phys. 9 358