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Scientific Articles - PTR-MS Bibliography

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Found 2 results
Title [ Year(Asc)]
Filters: Author is Griffis, Timothy J.  [Clear All Filters]
[1624] Hu, L., D. B. Millet, M. Baasandorj, T. J. Griffis, K. R. Travis, C. W. Tessum, J. D. Marshall, W. F. Reinhart, T. Mikoviny, M. Müller, et al., "Emissions of C 6 -C 8 aromatic compounds in the United States: Constraints from tall tower and aircraft measurements", Journal of Geophysical Research: Atmospheres, vol. 120, pp. 826–842, Jan, 2015.
<p>We present two full years of continuous C6&ndash;C8 aromatic compound measurements by PTR-MS at the KCMP tall tower (Minnesota, US) and employ GEOS-Chem nested grid simulations in a Bayesian inversion to interpret the data in terms of new constraints on US aromatic emissions. Based on the tall tower data, we find that the RETRO inventory (year-2000) overestimates US C6&ndash;C8 aromatic emissions by factors of 2.0&ndash;4.5 during 2010&ndash;2011, likely due in part to post-2000 reductions. Likewise, our implementation of the US EPA&#39;s NEI08 overestimates the toluene flux by threefold, reflecting an inventory bias in non-road emissions plus uncertainties associated with species lumping. Our annual top-down emission estimates for benzene and C8 aromatics agree with the NEI08 bottom-up values, as does the inferred contribution from non-road sources. However, the NEI08 appears to underestimate on-road emissions of these compounds by twofold during the warm season. The implied aromatic sources upwind of North America are more than double the prior estimates, suggesting a substantial underestimate of East Asian emissions, or large increases there since 2000. Long-range transport exerts an important influence on ambient benzene over the US: on average 43% of its wintertime abundance in the US Upper Midwest is due to sources outside North America. Independent aircraft measurements show that the inventory biases found here for C6&ndash;C8 aromatics also apply to other parts of the US, with notable exceptions for toluene in California and Houston, Texas. Our best estimates of year-2011 contiguous US emissions are 206 (benzene), 408 (toluene), and 822 (C8 aromatics) GgC.</p>
[1625] Hu, L., D. B. Millet, M. Baasandorj, T. J. Griffis, P. Turner, D. Helmig, A. J. Curtis, and J. Hueber, "Isoprene emissions and impacts over an ecological transition region in the US Upper Midwest inferred from tall tower measurements", Journal of Geophysical Research: Atmospheres, Mar, 2015.
<p>We present one year of in-situ PTR-MS measurements of isoprene and its oxidation products MVK and MACR from a 244 m tall tower in the US Upper Midwest, located at an ecological transition between isoprene-emitting deciduous forest and predominantly non-isoprene-emitting agricultural landscapes. We find that anthropogenic interferences (or anthropogenic isoprene) contribute on average 20% of the PTR-MS m/z 69 signal during summer daytime, whereas MVK+MACR interferences (m/z 71) are minor (7%). After removing these interferences, the observed isoprene and MVK+MACR abundances show pronounced seasonal cycles, reaching summertime maxima of &gt;2500 pptv (1-hour mean). The tall tower is impacted both by nearby and more distant regional isoprene sources, with daytime enhancements of isoprene (but little MVK+MACR) under southwest winds, and enhancements of MVK+MACR (but little isoprene) at other times. We find that the GEOS-Chem atmospheric model with the MEGANv2.1 biogenic inventory can reproduce the isoprene observations to within model uncertainty given improved land cover and temperature estimates. However, a 60% low model bias in MVK+MACR cannot be resolved, even across diverse model assumptions for NOx emissions, chemistry, atmospheric mixing, dry deposition, land cover, and potential measurement interferences. This implies that, while isoprene emissions in the immediate vicinity of the tall tower are adequately captured, they are underestimated across the broader region. We show that this region experiences a strong seasonal shift between VOC-limited chemistry during the spring and fall and NOx-limited or transitional chemistry during the summer, driven by the spatiotemporal distribution of isoprene emissions. Isoprene&#39;s role in causing these chemical shifts is likely underestimated due to the underprediction of its regional emissions.</p>

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Selected PTR-MS related Reviews

F. Biasioli, C. Yeretzian, F. Gasperi, T. D. Märk: PTR-MS monitoring of VOCs and BVOCs in food science and technology, Trends in Analytical Chemistry 30 (7) (2011).

J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, R. Fall: Measurement of Volatile Organic Compounds in the Earth's Atmosphere using Proton-Transfer-Reaction Mass Spectrometry. Mass Spectrometry Reviews, 26 (2007), 223-257.

W. Lindinger, A. Hansel, A. Jordan: Proton-transfer-reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev. 27 (1998), 347-375.


Lists with PTR-MS relevant publications of the University of Innsbruck can be found here: Atmospheric and indoor air chemistry, IMR, Environmental Physics and Nano-Bio-Physics


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