Measurement of relative humidity dependent light scattering of aerosols

Typ
01A - Beitrag in wissenschaftlicher Zeitschrift
Herausgeber:innen
Herausgeber:in (Körperschaft)
Betreuer:in
Übergeordnetes Werk
Atmospheric Measurement Techniques
Themenheft
DOI der Originalpublikation
Link
Reihe / Serie
Reihennummer
Jahrgang / Band
3
Ausgabe / Nummer
1
Seiten / Dauer
39-50
Patentnummer
Verlag / Herausgebende Institution
Copernicus
Verlagsort / Veranstaltungsort
Göttingen
Auflage
Version
Programmiersprache
Abtretungsempfänger:in
Praxispartner:in/Auftraggeber:in
Zusammenfassung
Relative humidity (RH) influences the water content of aerosol particles and therefore has an important impact on the particles' ability to scatter visible light. The RH dependence of the particle light scattering coefficient (σsp is therefore an important measure for climate forcing calculations. We built a humidification system for a nephelometer which allows the measurement of σsp at a defined RH in the range of 40–90%. This RH conditioner consists of a humidifier followed by a dryer, which enables us to measure the hysteresis behavior of deliquescent aerosol particles. In this paper we present the set-up of a new humidified nephelometer, a detailed characterization with well defined laboratory generated aerosols, and a first application in the field by comparing our instrument to another humidified nephelometer. Monodisperse ammonium sulfate and sodium chloride particles were measured at four different dry particle sizes. Agreement between measurement and prediction based on Mie theory was found for both σsp and f(RH)=σsp(RH)/σsp(dry) within the range of uncertainty. The two humidified nephelometers measuring at a rural site in the Black Forest (Germany) often detected different f(RH), probably caused by the aerosol hysteresis behavior: when the aerosol was metastable, therefore was scattering more light, only one instrument detected the higher f(RH).
Schlagwörter
Fachgebiet (DDC)
550 - Geowissenschaften
Projekt
Veranstaltung
Startdatum der Ausstellung
Enddatum der Ausstellung
Startdatum der Konferenz
Enddatum der Konferenz
Datum der letzten Prüfung
ISBN
ISSN
1867-8548
1867-1381
Sprache
Englisch
Während FHNW Zugehörigkeit erstellt
Nein
Zukunftsfelder FHNW
Publikationsstatus
Veröffentlicht
Begutachtung
Peer-Review der ganzen Publikation
Open Access-Status
Gold
Lizenz
'https://creativecommons.org/licenses/by/4.0/'
Zitation
FIERZ-SCHMIDHAUSER, Rahel, Paul ZIEGER, Günther WEHRLE, Anne JEFFERSON, John A. OGREN, Urs BALTENSPERGER und Ernest WEINGARTNER, 2010. Measurement of relative humidity dependent light scattering of aerosols. Atmospheric Measurement Techniques. 21 Januar 2010. Bd. 3, Nr. 1, S. 39–50. DOI 10.5194/amt-3-39-2010. Verfügbar unter: https://doi.org/10.26041/fhnw-9676