edu.ucar.opensky::articles:18238 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T03:28:50.357937 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7r212xz Eddy covariance measurements of isoprene and 232-MBO based on NO+ time-of-flight mass spectrometry 2014-05-15T00:00:00Z publication https://n2t.org/ark:/85065/d7r212xz https://doi.org/10.1016/j.ijms.2013.12.002 Karl, T. author Kaser, Lisa author Turnipseed, Andrew A. author UCAR/NCAR - Library publisher Isoprene and 2-methyl-3-buten-2-ol (232-MBO) are the dominant biogenic VOCs released throughout the US, thus requiring simultaneous measurements. Recent measurements suggest the presence of isoprene in 232-MBO dominated ecosystems, however analytical difficulties make it problematic to detect both species independently. Based on a new chemical ionization scheme we use eddy covariance measurements to selectively measure fluxes of both species without analytical interference at the Manitou Experimental Forest (MEF) in Colorado. Our measurements show a concentration ratio between isoprene and 232 MBO of 0.24 (ppbv/ppbv), and a flux ratio of 0.10 ([ppbv m/s]/[ppbv m/s]). Daytime average emission factors of isoprene and 232 MBO were 1.4 ± 0.3 and 16.0 ± 3.0 mg/m2/h respectively. Both compounds exhibit light and temperature dependent fluxes. These findings suggest that isoprene is both locally produced and transported to the measurement site dominated by ponderosa pine. This makes it difficult to use MVK and MAC as tracers for estimating the photochemical age of isoprene chemistry at this site. Further our measurements suggest that isoprene can contribute to about 15% of the OH reactivity relative to 232 MBO. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2014 Elsevier. None eng geoscientificInformation