13-month climatology of the aerosol hygroscopicity at the free tropospheric site Jungfraujoch (3580 m a.s.l.)
Loading...
Authors
Author (Corporation)
Publication date
16.11.2010
Typ of student thesis
Course of study
Collections
Type
01A - Journal article
Editors
Editor (Corporation)
Supervisor
Parent work
Atmospheric Chemistry and Physics
Special issue
DOI of the original publication
Link
Series
Series number
Volume
10
Issue / Number
22
Pages / Duration
10717-10732
Patent number
Publisher / Publishing institution
Copernicus
Place of publication / Event location
Göttingen
Edition
Version
Programming language
Assignee
Practice partner / Client
Abstract
A hygroscopicity tandem differential mobility analyzer (HTDMA) was operated at the high-alpine site Jungfraujoch in order to characterize the hygroscopic diameter growth factors of the free tropospheric Aitken and accumulation mode aerosol. More than ~5000 h of valid data were collected for the dry diameters D0 = 35, 50, 75, 110, 165, and 265 nm during the 13-month measurement period from 1 May 2008 through 31 May 2009. No distinct seasonal variability of the hygroscopic properties was observed. Annual mean hygroscopic diameter growth factors (D/D0) at 90% relative humidity were found to be 1.34, 1.43, and 1.46 for D0 = 50, 110, and 265 nm, respectively. This size dependence can largely be attributed to the Kelvin effect because corresponding values of the hygroscopicity parameter κ are nearly independent of size. The mean hygroscopicity of the Aitken and accumulation mode aerosol at the free tropospheric site Jungfraujoch was found to be κ≈0.24 with little variability throughout the year. The impact of Saharan dust events, a frequent phenomenon at the Jungfraujoch, on aerosol hygroscopicity was shown to be negligible for D0<265 nm. Thermally driven injections of planetary boundary layer (PBL) air, particularly observed in the early afternoon of summer days with convective anticyclonic weather conditions, lead to a decrease of aerosol hygroscopicity. However, the effect of PBL influence is not seen in the annual mean hygroscopicity data because the effect is small and those conditions (weather class, season and time of day) with PBL influence are relatively rare. Aerosol hygroscopicity was found to be virtually independent of synoptic wind direction during advective weather situations, i.e. when horizontal motion of the atmosphere dominates over thermally driven convection. This indicates that the hygroscopic behavior of the aerosol observed at the Jungfraujoch can be considered representative of the lower free troposphere on at least a regional if not continental scale.
Keywords
Subject (DDC)
550 - Geowissenschaften
Event
Exhibition start date
Exhibition end date
Conference start date
Conference end date
Date of the last check
ISBN
ISSN
1680-7324
1680-7316
1680-7316
Language
English
Created during FHNW affiliation
No
Strategic action fields FHNW
Publication status
Published
Review
Peer review of the complete publication
Open access category
Gold
Citation
KAMMERMANN, Lukas, Martin GYSEL, Ernest WEINGARTNER und Urs BALTENSPERGER, 2010. 13-month climatology of the aerosol hygroscopicity at the free tropospheric site Jungfraujoch (3580 m a.s.l.). Atmospheric Chemistry and Physics. 16 November 2010. Bd. 10, Nr. 22, S. 10717–10732. DOI 10.5194/acp-10-10717-2010. Verfügbar unter: https://doi.org/10.26041/fhnw-9666