Influence of gas-to-particle partitioning on the hygroscopic and droplet activation behaviour of α-pinene secondary organic aerosol

被引：46

作者：

Juranyi, Zsofia ^{[1
]}

Gysel, Martin ^{[1
]}

Duplissy, Jonathan ^{[1
]}

Weingartner, Ernest ^{[1
]}

Tritscher, Torsten ^{[1
]}

Dommen, Josef ^{[1
]}

Henning, Silvia ^{[2
]}

Ziese, Markus ^{[2
]}

Kiselev, Alexej ^{[2
]}

Stratmann, Frank ^{[2
]}

George, Ingrid ^{[3
]}

Baltensperger, Urs ^{[1
]}

机构：

[1] Paul Scherrer Inst, Lab Atmospher Chem, Villigen, Switzerland

[2] Leibniz Inst Tropospher Res, Leipzig, Germany

[3] Univ Toronto, Dept Chem, Toronto, ON M5S 1A1, Canada

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2009年 / 11卷 / 36期

基金：

瑞士国家科学基金会;

关键词：

SINGLE-PARAMETER REPRESENTATION; AMMONIUM-SULFATE; CCN ACTIVATION; GROWTH; NUCLEUS; KINETICS; CHAMBER;

D O I：

10.1039/b904162a

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Hygroscopic properties of secondary organic aerosol (SOA) formed by photooxidation of different concentrations (10-27 or 220-270 ppb) of a-pinene precursor were investigated at different relative humidities (RH) using a hygroscopicity tandem differential mobility analyzer (HTDMA, RH = 95-97%) and using the mobile version of the Leipzig Aerosol Cloud Interaction Simulator (LACIS-mobile, RH = 98-99.3%). In addition, the cloud condensation nuclei (CCN) activity was measured applying two CCN counters (CCNC). An apparent single-hygroscopicity parameter, kappa, of similar to 0.09, similar to 0.07-0.13, and similar to 0.02-0.04 was derived from CCNC, HTDMA and LACIS data, respectively, assuming the surface tension of pure water. Closure between HTDMA and CCNC data was achieved within experimental uncertainty, whereas closure between LACIS and CCNC was only achieved by assuming a concentration-dependent surface tension reduction, consequently resulting in lower CCNC-derived k values. Comparing different experimental techniques at varying precursor concentrations in more detail reveals further open questions. Varying precursor concentration influences hygroscopic growth factors at subsaturated RH, while it has no effect on the CCN activation. This difference in behaviour might be caused by precursor concentration-dependent surface tension depression or changing droplet solution concentration dependence of the water activity coefficient with varying SOA composition. Furthermore, evidence was found that the SOA might need several seconds to reach the equilibrium growth factor at high RH.

引用

页码：8091 / 8097

页数：7

共 37 条

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