Measured and predicted aerosol light scattering enhancement factors at the high alpine site Jungfraujoch
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Autor:innen
Fierz-Schmidhauser, Rahel
Zieger, Paul
Gysel, Martin
Kammermann, Lukas
DeCarlo, Peter F.
Baltensperger, Urs
Autor:in (Körperschaft)
Publikationsdatum
05.03.2010
Typ der Arbeit
Studiengang
Typ
01A - Beitrag in wissenschaftlicher Zeitschrift
Herausgeber:innen
Herausgeber:in (Körperschaft)
Betreuer:in
Übergeordnetes Werk
Atmospheric Chemistry and Physics
Themenheft
DOI der Originalpublikation
Link
Reihe / Serie
Reihennummer
Jahrgang / Band
10
Ausgabe / Nummer
5
Seiten / Dauer
2319-2333
Patentnummer
Verlag / Herausgebende Institution
Copernicus
Verlagsort / Veranstaltungsort
Göttingen
Auflage
Version
Programmiersprache
Abtretungsempfänger:in
Praxispartner:in/Auftraggeber:in
Zusammenfassung
Ambient relative humidity (RH) determines the water content of atmospheric aerosol particles and thus has an important influence on the amount of visible light scattered by particles. The RH dependence of the particle light scattering coefficient (σsp) is therefore an important variable for climate forcing calculations. We used a humidification system for a nephelometer which allows for the measurement of σsp at a defined RH in the range of 20–95%. In this paper we present measurements of light scattering enhancement factors f(RH)=σsp(RH)/σsp(dry) from a 1-month campaign (May 2008) at the high alpine site Jungfraujoch (3580 m a.s.l.), Switzerland. Measurements at the Jungfraujoch are representative for the lower free troposphere above Central Europe. For this aerosol type hardly any information about the f(RH) is available so far. At this site, f(RH=85%) varied between 1.2 and 3.3. Measured f(RH) agreed well with f(RH) calculated with Mie theory using measurements of the size distribution, chemical composition and hygroscopic diameter growth factors as input. Good f(RH) predictions at RH<85% were also obtained with a simplified model, which uses the Ångström exponent of σsp(dry) as input. RH influences further intensive optical aerosol properties. The backscatter fraction decreased by about 30% from 0.128 to 0.089, and the single scattering albedo increased on average by 0.05 at 85% RH compared to dry conditions. These changes in σsp, backscatter fraction and single scattering albedo have a distinct impact on the radiative forcing of the Jungfraujoch aerosol.
Schlagwörter
Fachgebiet (DDC)
550 - Geowissenschaften
Veranstaltung
Startdatum der Ausstellung
Enddatum der Ausstellung
Startdatum der Konferenz
Enddatum der Konferenz
Datum der letzten Prüfung
ISBN
ISSN
1680-7324
1680-7316
1680-7316
Sprache
Englisch
Während FHNW Zugehörigkeit erstellt
Nein
Publikationsstatus
Veröffentlicht
Begutachtung
Peer-Review der ganzen Publikation
Open Access-Status
Gold
Lizenz
Zitation
FIERZ-SCHMIDHAUSER, Rahel, Paul ZIEGER, Martin GYSEL, Lukas KAMMERMANN, Peter F. DECARLO, Urs BALTENSPERGER und Ernest WEINGARTNER, 2010. Measured and predicted aerosol light scattering enhancement factors at the high alpine site Jungfraujoch. Atmospheric Chemistry and Physics. 5 März 2010. Bd. 10, Nr. 5, S. 2319–2333. DOI 10.5194/acp-10-2319-2010. Verfügbar unter: https://doi.org/10.26041/fhnw-9675