Search

Your search keyword '"Krechmer, J. E."' showing total 4 results
Start Over Author "Krechmer, J. E." Search Limiters Available in Library Collection
4 results on '"Krechmer, J. E."'

1. High Gas-Phase Methanesulfonic Acid Production in the OH-Initiated Oxidation of Dimethyl Sulfide at Low Temperatures

Author

Shen, Jiali, Scholz, Wiebke, He, Xu-Cheng, Zhou, Putian, Marie, Guillaume, Wang, Mingyi, Marten, Ruby, Surdu, Mihnea, Rörup, Birte, Baalbaki, Rima, Amorim, Antonio, Ataei, Farnoush, Bell, David M., Bertozzi, Barbara, Brasseur, Zoé, Caudillo, Lucía, Chen, Dexian, Chu, Biwu, Dada, Lubna, Duplissy, Jonathan, Finkenzeller, Henning, Granzin, Manuel, Guida, Roberto, Heinritzi, Martin, Hofbauer, Victoria, Iyer, Siddharth, Kemppainen, Deniz, Kong, Weimeng, Krechmer, J. E., Krechmer, Jordan E., Kürten, Andreas, Lamkaddam, Houssni, Lee, Chuan Ping, Lopez, Brandon, Mahfouz, Naser G. A., Manninen, Hanna E., Massabò, Dario, Mauldin, Roy L., Mentler, Bernhard, Müller, Tatjana, Pfeifer, Joschka, Philippov, Maxim, Piedehierro, Ana A., Roldin, Pontus, Schobesberger, Siegfried, Simon, Mario, Stolzenburg, Dominik, Tham, Yee Jun, Tomé, António, Umo, Nsikanabasi Silas, Wang, Dongyu, Wang, Yonghong, Weber, Stefan K., Welti, André, Wollesen de Jonge, Robin, Wu, Yusheng, Zauner-Wieczorek, Marcel, Zust, Felix, Baltensperger, Urs, Curtius, Joachim, Flagan, Richard C., Hansel, Armin, Möhler, Ottmar, Petäjä, Tuukka, Volkamer, Rainer, Kulmala, Markku, Lehtipalo, Katrianne, Rissanen, Matti, Kirkby, Jasper, El-Haddad, Imad, Bianchi, Federico, Sipilä, Mikko, Donahue, Neil M., and Worsnop, Douglas R.

Subjects
Earth sciences, ddc:550
Abstract

Dimethyl sulfide (DMS) influences climate via cloud condensation nuclei (CCN) formation resulting from its oxidation products (mainly methanesulfonic acid, MSA, and sulfuric acid, H$_{2}$SO$_{4}$). Despite their importance, accurate prediction of MSA and H$_{2}$SO$_{4}$ from DMS oxidation remains challenging. With comprehensive experiments carried out in the Cosmics Leaving Outdoor Droplets (CLOUD) chamber at CERN, we show that decreasing the temperature from +25 to −10 °C enhances the gas-phase MSA production by an order of magnitude from OH-initiated DMS oxidation, while H$_{2}$SO$_{4}$ production is modestly affected. This leads to a gas-phase H$_{2}$SO$_{4}$-to-MSA ratio (H$_{2}$SO$_{4}$/MSA) smaller than one at low temperatures, consistent with field observations in polar regions. With an updated DMS oxidation mechanism, we find that methanesulfinic acid, CH$_{3}$S(O)OH, MSIA, forms large amounts of MSA. Overall, our results reveal that MSA yields are a factor of 2–10 higher than those predicted by the widely used Master Chemical Mechanism (MCMv3.3.1), and the NO$_{x}$ effect is less significant than that of temperature. Our updated mechanism explains the high MSA production rates observed in field observations, especially at low temperatures, thus, substantiating the greater importance of MSA in the natural sulfur cycle and natural CCN formation. Our mechanism will improve the interpretation of present-day and historical gas-phase H$_{2}$SO$_{4}$/MSA measurements.

Published
2022
Full Text
View/download PDF

2. Characterization of a real-time tracer for isoprene epoxydiols-derived secondary organic aerosol (IEPOX-SOA) from aerosol mass spectrometer measurements

Author

Hu, W. W., primary, Campuzano-Jost, P., additional, Palm, B. B., additional, Day, D. A., additional, Ortega, A. M., additional, Hayes, P. L., additional, Krechmer, J. E., additional, Chen, Q., additional, Kuwata, M., additional, Liu, Y. J., additional, de Sá, S. S., additional, McKinney, K., additional, Martin, S. T., additional, Hu, M., additional, Budisulistiorini, S. H., additional, Riva, M., additional, Surratt, J. D., additional, St. Clair, J. M., additional, Isaacman-Van Wertz, G., additional, Yee, L. D., additional, Goldstein, A. H., additional, Carbone, S., additional, Brito, J., additional, Artaxo, P., additional, de Gouw, J. A., additional, Koss, A., additional, Wisthaler, A., additional, Mikoviny, T., additional, Karl, T., additional, Kaser, L., additional, Jud, W., additional, Hansel, A., additional, Docherty, K. S., additional, Alexander, M. L., additional, Robinson, N. H., additional, Coe, H., additional, Allan, J. D., additional, Canagaratna, M. R., additional, Paulot, F., additional, and Jimenez, J. L., additional

Published
2015
Full Text
View/download PDF

3. A Novel Framework for Molecular Characterization of Atmospheric Organic Aerosol Based on Collision Cross Section and Mass-to-Charge Ratio.

Author

Zhang, X., Krechmer, J. E., Groessl, M., Xu, W., Graf, S., Cubison, M., Jayne, J. T., Jimenez, J. L., Worsnop, D. R., and Canagaratna, M. R.

Abstract

A new metric is introduced for representing the molecular signature of atmospheric organic aerosols, the collision cross section (Ω), a quantity that is related to the structure and geometry of molecules and is derived from ion mobility measurements. By combination with the mass-to-charge ratio (m/z), a two-dimensional Ω-m/z space is developed to facilitate the comprehensive investigation of the complex organic aerosol mixture. A unique distribution pattern of chemical classes, characterized by functional groups including amine, alcohol, carbonyl, carboxylic acid, ester, and organic sulfate, is developed on the 2-D Ω-m/z space. Species of the same chemical class, despite variations in the molecular structures, tend to situate as a narrow band on the space and follow a trend line. Reactions involving changes in functionalization and fragmentation can be represented by the directionalities along or across these trend lines, thus allowing for the interpretation of mechanisms associated with the formation and evolution of atmospheric organic aerosol. The characteristics of trend lines for a variety of functionalities that are commonly present in ambient aerosols can be predicted by the core model simulations, which provide a useful tool to identify the chemical class to which an unknown species belongs on the Ω-m/z space. Within the band produced by each chemical class on the space, molecular structural assignment can be achieved by utilizing collision induced dissociation as well as by comparing the measured collision cross sections in the context of those obtained via molecular dynamics simulations. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

4. Evaluation of the chemical composition of gas- And particle-phase products of aromatic oxidation

Author

Mehra, A., Wang, Y., Krechmer, J. E., Lambe, A., Majluf, F., Morris, M. A., Priestley, M., Bannan, T. J., Bryant, D. J., Pereira, Kelly L., Hamilton, J. F., Rickard, A. R., Newland, M. J., Stark, H., Croteau, P., Jayne, J. T., Worsnop, D. R., Canagaratna, M. R., Wang, L., Coe, H., Mehra, A., Wang, Y., Krechmer, J. E., Lambe, A., Majluf, F., Morris, M. A., Priestley, M., Bannan, T. J., Bryant, D. J., Pereira, Kelly L., Hamilton, J. F., Rickard, A. R., Newland, M. J., Stark, H., Croteau, P., Jayne, J. T., Worsnop, D. R., Canagaratna, M. R., Wang, L., and Coe, H.

Abstract

Aromatic volatile organic compounds (VOCs) are key anthropogenic pollutants emitted to the atmosphere and are important for both ozone and secondary organic aerosol (SOA) formation in urban areas. Recent studies have indicated that aromatic hydrocarbons may follow previously unknown xidation chemistry pathways, including autoxidation that can lead to the formation of highly oxidised products. In this study we evaluate the gas- and particle-phase ions measured by online mass spectrometry during the hydroxyl radical oxidation of substituted C9-aromatic isomers (1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, propylbenzene and isopropylbenzene) and a substituted polyaromatic hydrocarbon (1-methylnaphthalene) under low- and medium-NOx conditions. A time-of-flight chemical ionisation mass spectrometer (ToF-CIMS) with iodide anion ionisation was used with a filter inlet for gases and aerosols (FIGAERO) for the detection of products in the particle phase, while a Vocus protontransfer- reaction mass spectrometer (Vocus-PTR-MS) was sed for the detection of products in the gas phase. The signal of product ions observed in the mass spectra were compared or the different precursors and experimental conditions. The majority of mass spectral product signal in both the gas and particle phases comes from ions which are common to all precursors, though signal distributions are distinct for different VOCs. Gas- and particle-phase composition are distinct from one another. Ions corresponding to products contained in the near-explicit gas phase Master Chemical Mechanism (MCM version 3.3.1) are utilised as a benchmark of current scientific understanding, and a comparison of these with observations shows that the MCM is missing a range of highly oxidised products from its mechanism. In the particle phase, the bulk of the product signal from all precursors comes from ring scission ions, a large proportion of which are more oxidised than previously reported and ave undergone further oxidat

Catalog

Books, media, physical & digital resources
See catalog results