Tropospheric Chemistry: Instruments

Laser Photo-Acoustic Spectroscopy (LPAS)

Decommissioned

LPAS instrument installed in rack on NOAA WP-3D aircraft

Principle of the Measurement

Excitation of ethylene inside a resonator using a modulated CO2 laser
Quenching of excited ethylene by collisions
Heat transfer leads to audible noise at the laser modulation frequency
Detection of noise with a microphone

Species Measured

Ethylene

Time Response / Detection Limit

4-20 seconds / 70-200 pptv

Manufacturer

Sensor Sense

Field Projects

INDOEX 1999
MINOS 2001
ITCT 2002
NEAQS 2002
ICARTT 2004
MILAGRO 2006
TexAQS 2006
BEARPEX 2007
ARCPAC 2008
ICEALOT 2008
CalNex 2010
NACHTT 2011
BioCORN 2011
SONNE 2012
UBWOS 2012
SENEX 2013

Key Publications

J.A. de Gouw, S. te Lintel Hekkert, J. Mellqvist, C. Warneke, E.L. Atlas, F.C. Fehsenfeld, A. Fried, G.J. Frost, F.J.M. Harren, J.S. Holloway, B. Lefer, R. Lueb, J.F. Meagher, D.D. Parrish, M. Patel, L. Pope, D. Richter, C. Rivera, T.B. Ryerson, J. Samuelsson, J. Walega, R.A. Washenfelder, P. Weibring and X. Zhu, Airborne measurements of ethene from industrial sources using laser photo-acoustic spectroscopy, Environmental Science & Technology, doi:10.1021/es802701a, 2009.

W.C. Kuster, F.J.M. Harren and J.A. de Gouw, Inter-comparison of laser photoacoustic spectroscopy and gas chromatography techniques for measurements of ethene in the atmosphere, Environmental Science & Technology, doi:10.1021/es0504385, 2005.