Eddy covariance emission and deposition flux measurements using proton transfer reaction – time of flight – mass spectrometry (PTR-TOF-MS): comparison with PTR-MS measured vertical gradients and fluxes

Park, J.-H.; Goldstein, Allen H.; Timkovsky, J.; Fares, Silvano; Weber, R. J.; Karlik, J.; Holzinger, Rupert

doi:10.5194/acp-13-1439-2013

Cited by 63 publications

(69 citation statements)

References 68 publications

(77 reference statements)

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“…There were also other controversial discoveries such as net emissions of m/z 93. A compound at m/z 93 is usually connected with toluene but it might be a fragmentation product of p-cymene as well (Ciccioli et al, 1999;Heiden et al, 1999;White et al, 2009;Ambrose et al, 2010;Park et al, 2013). We found a dependency between the m/z 93 fluxes and E/N where E is the electric field and N the number density of the gas in the drift tube.…”

Section: Statistical Significance Of Fluxesmentioning

confidence: 64%

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Annual cycle of volatile organic compound exchange between a boreal pine forest and the atmosphere

et al. 2015

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Abstract. Long-term flux measurements of volatile organic compounds (VOC) over boreal forests are rare, although the forests are known to emit considerable amounts of VOCs into the atmosphere. Thus, we measured fluxes of several VOCs and oxygenated VOCs over a Scots-pine-dominated boreal forest semi-continuously between May 2010 and December 2013. The VOC profiles were obtained with a proton transfer reaction mass spectrometry, and the fluxes were calculated using vertical concentration profiles and the surface layer profile method connected to the Monin-Obukhov similarity theory. In total fluxes that differed significantly from zero on a monthly basis were observed for 13 out of 27 measured masses. Monoterpenes had the highest net emission in all seasons and statistically significant positive fluxes were detected from March until October. Other important compounds emitted were methanol, ethanol+formic acid, acetone and isoprene+methylbutenol. Oxygenated VOCs showed also deposition fluxes that were statistically different from zero. Isoprene+methylbutenol and monoterpene fluxes followed well the traditional isoprene algorithm and the hybrid algorithm, respectively. Emission potentials of monoterpenes were largest in late spring and autumn which was possibly driven by growth processes and decaying of soil litter, respectively. Conversely, largest emission potentials of isoprene+methylbutenol were found in July. Thus, we concluded that most of the emissions of m/z 69 at the site consisted of isoprene that originated from broadleaved trees.Methanol had deposition fluxes especially before sunrise. This can be connected to water films on surfaces. Based on this assumption, we were able to build an empirical algorithm for bi-directional methanol exchange that described both emission term and deposition term. Methanol emissions were highest in May and June and deposition level increased towards autumn, probably as a result of increasing relative humidity levels leading to predominance of deposition.

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Section: Statistical Significance Of Fluxesmentioning

confidence: 64%

“…However, other compounds also might have a contribution at the measured masses (e.g. m/z 85, see Park et al, 2013). The second column shows whether a sensitivity was determined directly from the calibration or not (derived from a transmission curve, i.e.…”

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confidence: 99%

Annual cycle of volatile organic compound exchange between a boreal pine forest and the atmosphere

et al. 2015

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“…In the southern SJV, known organic sources likely to be temperature dependent are diverse and are arranged in an overlapping patchwork surrounding the CalNex-SJV site. These sources include emissions from dairy wastes (e.g., Shaw et al, 2007;Gentner et al, 2013a) and animal feeds (Alanis et al, 2010;Howard et al, 2010a, b;Malkina et al, 2011), biogenic emissions from crops (e.g., Ormeño et al, 2010;Fares et al, 2011Fares et al, , 2012Gentner et al, 2013b;Park et al, 2013a) and forests in the adjacent Sierra Nevada foothills (e.g., Schade and Goldstein, 2001;LaFranchi et al, 2011;Park et al, 2013b), and the evaporative emissions of oil and gas extraction activities, as suggested by our observation of temperature-dependent light alkane mixing ratios.…”

Section: Organic Reactivity and Temperaturementioning

confidence: 99%

“…In light of the CalNex-SJV i VOCR i and VOCR observations and well-documented efforts to control motor vehicle emissions (e.g., Kirchstetter et al, 1999a, b;Parrish et al, 2002;Harley et al, 2006;Parrish, 2006;Bishop and Stedman, 2008) we speculate that it is the temperatureindependent reactivity that has decreased over the last decade. At the same time, we know of no deliberate attempt to control the molecules dominating the reactivity at high temperatures -small aldehydes, alcohols, and the unknown VOCR.…”

Section: Organic Reactivity and Temperaturementioning

confidence: 99%

On the temperature dependence of organic reactivity, nitrogen oxides, ozone production, and the impact of emission controls in San Joaquin Valley, California

et al. 2014

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Abstract. The San Joaquin Valley (SJV) experiences some of the worst ozone air quality in the US, frequently exceeding the California 8 h standard of 70.4 ppb. To improve our understanding of trends in the number of ozone violations in the SJV, we analyze observed relationships between organic reactivity, nitrogen oxides (NO x ), and daily maximum temperature in the southern SJV using measurements made as part of California at the Nexus of Air Quality and Climate Change in 2010 (CalNex-SJV). We find the daytime speciated organic reactivity with respect to OH during CalNex-SJV has a temperature-independent portion with molecules typically associated with motor vehicles being the major component.Published by Copernicus Publications on behalf of the European Geosciences Union. S. E. Pusede et al.: Temperature-dependent impacts of emission controlsAt high temperatures, characteristic of days with high ozone, the largest portion of the total organic reactivity increases exponentially with temperature and is dominated by small, oxygenated organics and molecules that are unidentified. We use this simple temperature classification to consider changes in organic emissions over the last and next decade. With the CalNex-SJV observations as constraints, we examine the sensitivity of ozone production (P O 3 ) to future NO x and organic reactivity controls. We find that P O 3 is NO x -limited at all temperatures on weekends and on weekdays when daily maximum temperatures are greater than 29 • C. As a consequence, NO x reductions are the most effective control option for reducing the frequency of future ozone violations in the southern SJV.

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“…PTR-TOF and PTR-QMS have recently been successfully compared (Kaser et al, 2013;Park et al, 2013). In Fig.…”

Section: Mixing Ratiosmentioning

confidence: 99%

PTR-QMS versus PTR-TOF comparison in a region with oil and natural gas extraction industry in the Uintah Basin in 2013

et al. 2015

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Abstract.Here we compare volatile organic compound (VOC) measurements using a standard proton-transferreaction quadrupole mass spectrometer (PTR-QMS) with a new proton-transfer-reaction time of flight mass spectrometer (PTR-TOF) during the Uintah Basin Winter Ozone Study 2013 (UBWOS2013) field experiment in an oil and gas field in the Uintah Basin, Utah. The PTR-QMS uses a quadrupole, which is a mass filter that lets one mass to charge ratio pass at a time, whereas the PTR-TOF uses a time of flight mass spectrometer, which takes full mass spectra with typical 0.1 s-1 min integrated acquisition times. The sensitivity of the PTR-QMS in units of counts per ppbv (parts per billion by volume) is about a factor of 10-35 times larger than the PTR-TOF, when only one VOC is measured. The sensitivity of the PTR-TOF is mass dependent because of the mass discrimination caused by the sampling duty cycle in the orthogonal-acceleration region of the TOF. For example, the PTR-QMS on mass 33 (methanol) is 35 times more sensitive than the PTR-TOF and for masses above 120 amu less than 10 times more. If more than 10-35 compounds are measured with PTR-QMS, the sampling time per ion decreases and the PTR-TOF has higher signals per unit measuring time for most masses. For UBWOS2013 the PTR-QMS measured 34 masses in 37 s and on that timescale the PTR-TOF is more sensitive for all masses. The high mass resolution of the TOF allows for the measurements of compounds that cannot be separately detected with the PTR-QMS, such as oxidation products from alkanes and cycloalkanes emitted by oil and gas extraction. PTR-TOF masses do not have to be preselected, allowing for identification of unanticipated compounds. The measured mixing ratios of the two instruments agreed very well (R 2 ≥ 0.92 and within 20 %) for all compounds and masses monitored with the PTR-QMS.

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Eddy covariance emission and deposition flux measurements using proton transfer reaction – time of flight – mass spectrometry (PTR-TOF-MS): comparison with PTR-MS measured vertical gradients and fluxes

Cited by 63 publications

References 68 publications

Annual cycle of volatile organic compound exchange between a boreal pine forest and the atmosphere

Annual cycle of volatile organic compound exchange between a boreal pine forest and the atmosphere

On the temperature dependence of organic reactivity, nitrogen oxides, ozone production, and the impact of emission controls in San Joaquin Valley, California

PTR-QMS versus PTR-TOF comparison in a region with oil and natural gas extraction industry in the Uintah Basin in 2013

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