Atmospheric variability of biogenic VOCs in the surface layer measured by proton-transfer-reaction mass spectrometry

TitleAtmospheric variability of biogenic VOCs in the surface layer measured by proton-transfer-reaction mass spectrometry
Publication TypeJournal Article
Year of Publication2004
AuthorsKarl T, Guenther A
JournalInternational Journal of Mass Spectrometry
Volume239
Issue2-3
Pagination77 - 86
Date Published12/2004
KeywordsVOLATILE ORGANIC COMPOUNDS
Abstract

Fast response measurements of biogenic volatile organic compounds (VOC) using proton-transfer-reaction mass spectrometry (PTR-MS) were conducted above a deciduous temperate, a tropical rain and an evergreen needle forest.We explore howthe variance of a compound relates to the surface flux and lifetime (τ) at these sites. Our results suggest that a modified variance method can be used for estimating surface fluxes of isoprene and methanol above sites characterized by homogenous surface emissions. The normalized variability σC/C, generally used for variability–lifetime relationships, increases as a function of averaging period, and follows an inverse lifetime-dependence. The variability of short-lived compound lies within the predicted range for mixed layer parameterizations such as the top-down (TD)–bottom-up (BU) variance functions. For lifetimes >1 day, significant deviation due to mesoscale processes adds to the variability on timescales above ∼30min.

DOI10.1016/j.ijms.2004.09.023