2025
Kanaya, Y., Sommariva, R., Saiz-Lopez, A., Mazzeo, A., Koenig, T.K., Kawana, K., Johnson, J.E., Colomb, A., Tulet, P., Molloy, S., Galbally, I.E., Volkamer, R., Mahajan, A., Halfacre, J.W., Shepson, P.B., Schmale, J., Angot, H., Blomquist, B., Shupe, M.D., Helmig, D., Gil, J., Lee, M., Coburn, S.C., Ortega, I., Chen, G., Lee, J., Aikin, K.C., Parrish, D.D., Holloway, J.S., Ryerson, T.B., Pollack, I.B., Williams, E.J., Lerner, B.M., Weinheimer, A.J., Campos, T., Flocke, F.M., Spackman, J.R., Bourgeois, I., Peischl, J., Thompson, C.R., Staebler, R.M., Aliabadi, A.A., Gong, W., Van Malderen, R., Thompson, A.M., Stauffer, R.M., Kollonige, D.E., Gómez Martin, J.C., Fujiwara, M., Read, K., Rowlinson, M., Sato, K., Kurokawa, J., Iwamoto, Y., Taketani, F., Takashima, H., Navarro Comas, M., Panagi, M., Schultz, M.G., 2025. Observational ozone data over the global oceans and polar regions: The TOAR-II Oceans data set version 2024. https://doi.org/10.5194/essd-2024-566
Helmig, D., Caputi, D., 2025. Top-down versus bottom-up atmospheric emission estimates from oil and natural gas operations. Manuscript submitted for publication.
Caputi, D., Helmig, D., Darby, L.S., Greenberg, G., Hueber, J., Simoncic, S., Ortega, J., 2025. Late winter ozone and PM 2.5 NAAQS exceedance in the Northern Colorado Front Range in relation to oil and natural gas emissions. J. Geophys. Res. Atmos. 130, e2024JD041862. https://doi.org/10.1029/2024JD041862
Helmig, D., Greenberg, G., Hueber, J., Blanchard, B., Chopra, J., Simoncic, S., Angot, H., Darby, L.S., Ortega, J., Caputi, D., 2025. Methane and volatile organic compounds and their influence on air quality in Boulder, Colorado. Elem. Sci. Anth. 13, 00117. https://doi.org/10.1525/elementa.2023.00117
2024
Langford, A.O., Alvarez II, R.J., Aikin, K.C., Baidar, S., Brewer, W.A., Brown, S.S., Coggan, M.M., Cullis, P.D., Gilman, J., Gkatzelis, G.I., Helmig, D., Johnson, B.J., Knowland, K.E., Kumar, R., Lamplugh, A.D., McClure-Begley, A., McCarty, B.J., Middlebrook, A.M., Pfister, G., Peischl, J., Petropavlovskikh, I., Rickley, P.S., Rollins, A.W., Sandberg, S.P., Senff, C.J., Warneke, C., 2024. An unusual winter ozone event in Colorado. EGUsphere. https://doi.org/10.5194/egusphere-2024-1938
Vermeuel, M.P., Millet, D.B., Farmer, D.K., Ganzeveld, L.N., Visser, A.J., Alwe, H.D., Bertram, T.H., Cleary, P.A., Desai, A.R., Helmig, D., Kavassalis, S.C., Link, M.F., Pothier, M.A., Riches, M., Wang, W., Williams, S., 2024. A vertically resolved canopy improves chemical transport model predictions of ozone deposition to north temperate forests. J. Geophys. Res. Atmos. 129, e2024JD042092. https://doi.org/10.1029/2024JD042092
Helmig, D., Nobel, J., Caputi, D., Brown, D., Daly, R.W., Darby, L.S., Doe, P.T., Gonzalez, O., Greenberg, G., Hueber, J., Potter, K., Schade, G.W., Simoncic, S., Stahli, M., Subra, W., 2024. Elevated airborne radioactivity downwind of a Colorado oil refinery. J. Air Waste Manag. Assoc. 74, 920–931. https://doi.org/10.1080/10962247.2024.2393194
Rowlinson, M.J., Evans, M.J., Carpenter, L.J., Read, K.A., Punjabi, S., Adedeji, A., Fakes, L., Lewis, A., Richmond, B., Passant, N., Murrells, T., Henderson, B., Bates, K.H., Helmig, D., 2024. Revising VOC emissions speciation improves the simulation of global background ethane and propane. Atmos. Chem. Phys. 24, 8317–8342. https://doi.org/10.5194/acp-24-8317-2024
2023
Ahmed, S., Thomas, J.L., Angot, H., Dommergue, A., Archer, S.D., Bariteau, L., Beck, I., Benavent, N., Blechschmidt, A.-M., Blomquist, B., Boyer, M., Christensen, J.H., Dahlke, S., Dastoor, A., Helmig, D., Howard, D., Jacobi, H.-W., Jokinen, T., Lapere, R., Laurila, T., Quéléver, L.L.J., Richter, A., Ryjkov, A., Mahajan, A.S., Marelle, L., Pfaffhuber, K.A., Posman, K., Rinke, A., Saiz-Lopez, A., Schmale, J., Skov, H., Steffen, A., Stupple, G., Stutz, J., Travnikov, O., Zilker, B., 2023. Modelling the coupled mercury-halogen-ozone cycle in the central Arctic during spring. Elem. Sci. Anth. 11, 00129. https://doi.org/10.1525/elementa.2022.00129
Yue, F., Angot, H., Blomquist, B., Schmale, J., Hoppe, C.J.M., Lei, R., Shupe, M.D., Zhan, L., Ren, J., Liu, H., Beck, I., Howard, D., Jokinen, T., Laurila, T., Quéléver, L., Boyer, M., Petäjä, T., Archer, S., Bariteau, L., Helmig, D., Hueber, J., Jacobi, H.-W., Posman, K., Xie, Z., 2023. The Marginal Ice Zone as a dominant source region of atmospheric mercury during central Arctic summertime. Nat. Commun. 14, 4887. https://doi.org/10.1038/s41467-023-40660-9
Tham, Y.J., Sarnela, N., Iyer, S., Li, Q., Angot, H., Quéléver, L.L.J., Beck, I., Laurila, T., Beck, L.J., Boyer, M., Carmona-García, J., Borrego-Sánchez, A., Roca-Sanjuán, D., Peräkylä, O., Thakur, R.C., He, X.-C., Zha, Q., Howard, D., Blomquist, B., Archer, S.D., Bariteau, L., Posman, K., Hueber, J., Helmig, D., Jacobi, H.-W., Junninen, H., Kulmala, M., Mahajan, A.S., Massling, A., Skov, H., Sipilä, M., Francisco, J.S., Schmale, J., Jokinen, T., Saiz-Lopez, A., 2023. Widespread detection of chlorine oxyacids in the Arctic atmosphere. Nat. Commun. 14, 1769. https://doi.org/10.1038/s41467-023-37387-y
2022
Helmig, D., Guenther, A., Hueber, J., Daly, R., Park, J.-H., Liikanen, A., Praplan, A.P., 2022. Ozone reactivity measurement of biogenic volatile organic compound emissions. Atmos. Meas. Tech. 15, 5439–5454. https://doi.org/10.5194/amt-2021-354
Angot, H., Blomquist, B., Howard, D., Archer, S., Bariteau, L., Beck, I., Boyer, M., Crotwell, M., Helmig, D., Hueber, J., Jacobi, H.-W., Jokinen, T., Kulmala, M., Lan, X., Laurila, T., Madronich, M., Neff, D., Petäjä, T., Posman, K., Quéléver, L., Shupe, M.D., Vimont, I., Schmale, J., 2022. Year-round trace gas measurements in the central Arctic during the MOSAiC expedition. Sci Data 9, 723. https://doi.org/10.1038/s41597-022-01769-6
Selimovic, V., Ketcherside, D., Chaliyakunnel, S., Wielgasz, C., Permar, W., Angot, H., Millet, D.B., Fried, A., Helmig, D., Hu, L., 2022. Atmospheric biogenic volatile organic compounds in the Alaskan Arctic tundra: constraints from measurements at Toolik Field Station. Atmos. Chem. Phys. 22, 14037–14058. https://doi.org/10.5194/acp-22-14037-2022
Barbero, A., Grilli, R., Frey, M.M., Blouzon, C., Helmig, D., Caillon, N., Savarino, J., 2022. Summer variability of the atmospheric NO2 : NO ratio at Dome C on the East Antarctic Plateau. Atmos. Chem. Phys. 22, 12025–12054. https://doi.org/10.5194/acp-22-12025-2022
Benavent, N., Mahajan, A.S., Li, Q., Cuevas, C.A., Schmale, J., Angot, H., Jokinen, T., Quéléver, L.L.J., Blechschmidt, A.-M., Zilker, B., Richter, A., Serna, J.A., Garcia-Nieto, D., Fernandez, R.P., Skov, H., Dumitrascu, A., Simões Pereira, P., Abrahamsson, K., Bucci, S., Duetsch, M., Stohl, A., Beck, I., Laurila, T., Blomquist, B., Howard, D., Archer, S.D., Bariteau, L., Helmig, D., Hueber, J., Jacobi, H.-W., Posman, K., Dada, L., Daellenbach, K.R., Saiz-Lopez, A., 2022. Substantial contribution of iodine to Arctic ozone destruction. Nat. Geosci. 15, 770–773. https://doi.org/10.1038/s41561-022-01018-w
Ahmed, S., Thomas, J.L., Tuite, K., Stutz, J., Flocke, F., Orlando, J.J., Hornbrook, R.S., Apel, E.C., Emmons, L.K., Helmig, D., Boylan, P., Huey, L.G., Hall, S.R., Ullmann, K., Cantrell, C.A., Fried, A., 2022. The role of snow in controlling halogen chemistry and boundary layer oxidation during arctic spring: A 1D modeling case study. J. Geophys. Res. Atmos. 127, e2021JD036140. https://doi.org/10.1029/2021JD036140
Shupe, M.D., Rex, M., Blomquist, B., Persson, P.O.G., Schmale, J., Uttal, T., Althausen, D., Angot, H., Archer, S., Bariteau, L., Beck, I., Bilberry, J., Bucci, S., Buck, C., Boyer, M., Brasseur, Z., Brooks, I.M., Calmer, R., Cassano, J., Castro, V., Chu, D., Costa, D., Cox, C.J., Creamean, J., Crewell, S., Dahlke, S., Damm, E., De Boer, G., Deckelmann, H., Dethloff, K., Dütsch, M., Ebell, K., Ehrlich, A., Ellis, J., Engelmann, R., Fong, A.A., Frey, M.M., Gallagher, M.R., Ganzeveld, L., Gradinger, R., Graeser, J., Greenamyer, V., Griesche, H., Griffiths, S., Hamilton, J., Heinemann, G., Helmig, D., Herber, A., Heuzé, C., Hofer, J., Houchens, T., Howard, D., Inoue, J., Jacobi, H.-W., Jaiser, R., Jokinen, T., Jourdan, O., Jozef, G., King, W., Kirchgaessner, A., Klingebiel, M., Krassovski, M., Krumpen, T., Lampert, A., Landing, W., Laurila, T., Lawrence, D., Lonardi, M., Loose, B., Lüpkes, C., Maahn, M., Macke, A., Maslowski, W., Marsay, C., Maturilli, M., Mech, M., Morris, S., Moser, M., Nicolaus, M., Ortega, P., Osborn, J., Pätzold, F., Perovich, D.K., Petäjä, T., Pilz, C., Pirazzini, R., Posman, K., Powers, H., Pratt, K.A., Preußer, A., Quéléver, L., Radenz, M., Rabe, B., Rinke, A., Sachs, T., Schulz, A., Siebert, H., Silva, T., Solomon, A., Sommerfeld, A., Spreen, G., Stephens, M., Stohl, A., Svensson, G., Uin, J., Viegas, J., Voigt, C., Von Der Gathen, P., Wehner, B., Welker, J.M., Wendisch, M., Werner, M., Xie, Z., Yue, F., 2022. Overview of the MOSAiC expedition: Atmosphere. Elem. Sci. Anthro. 10, 00060. https://doi.org/10.1525/elementa.2021.00060
Helmig, D., Fangmeyer, J., Fuchs, J., Hueber, J., Smith, K., 2022. Evaluation of selected solid adsorbents for passive sampling of atmospheric oil and natural gas non-methane hydrocarbons. J. Air Waste Manag. Assoc. 72, 235–255. https://doi.org/10.1080/10962247.2021.2000518
2021
Rossabi, S., Hueber, J., Wang, W., Milmoe, P., Helmig, D., 2021. Spatial distribution of atmospheric oil and natural gas volatile organic compounds in the Northern Colorado Front Range. Elem. Sci. Anthro. 9, 00036. https://doi.org/10.1525/elementa.2019.00036
Angot, H., Davel, C., Wiedinmyer, C., Pétron, G., Chopra, J., Hueber, J., Blanchard, B., Bourgeois, I., Vimont, I., Montzka, S.A., Miller, B.R., Elkins, J.W., Helmig, D., 2021. Temporary pause in the growth of atmospheric ethane and propane in 2015–2018. Atmos. Chem. Phys. 21, 15153–15170. https://doi.org/10.5194/acp-21-15153-2021
Pollack, I.B., Helmig, D., O’Dell, K., Fischer, E.V., 2021. Weekend‐Weekday implications and the impact of wildfire smoke on ozone and its precursors at Boulder Reservoir, Colorado Between 2017 and 2019. J. Geophys. Res. Atmos. 126, e2021JD035221. https://doi.org/10.1029/2021JD035221
Oltmans, S.J., Cheadle, L.C., Helmig, D., Angot, H., Pétron, G., Montzka, S.A., Dlugokencky, E.J., Miller, B., Hall, B., Schnell, R.C., Kofler, J., Wolter, S., Crotwell, M., Siso, C., Tans, P., Andrews, A., 2021. Atmospheric oil and natural gas hydrocarbon trends in the Northern Colorado Front Range are notably smaller than inventory emissions reductions. Elem. Sci. Anthro. 9, 00136. https://doi.org/10.1525/elementa.2020.00136
Darby, L.S., Senff, C.J., Alvarez II, R.J., Banta, R.M., Bianco, L., Helmig, D., White, A.B., 2021. Spatial and temporal variability of ozone along the Colorado Front Range occurring over 2 days with contrasting wind flow. Elem. Sci. Anth. 9, 00146. https://doi.org/10.1525/elementa.2020.00146
Pollack, I.B., Helmig, D., O’Dell, K., Fischer, E.V., 2021. Seasonality and source apportionment of nonmethane volatile organic compounds at Boulder Reservoir, Colorado, Between 2017 and 2019. J. Geophys. Res. Atmos. 126, e2020JD034234. https://doi.org/10.1029/2020JD034234
Asher, E., Hills, A.J., Hornbrook, R.S., Shertz, S., Gabbard, S., Stephens, B.B., Helmig, D., Apel, E.C., 2021. Unpiloted aircraft system instrument for the rapid collection of whole air samples and measurements for environmental monitoring and air quality studies. Environ. Sci. Technol. 55, 5657–5667. https://doi.org/10.1021/acs.est.0c07213
2020
Pozzer, A., Schultz, M.G., Helmig, D., 2020. Impact of U.S. oil and natural gas emission increases on surface ozone is most pronounced in the Central United States. Environ. Sci. Technol. 54, 12423–12433. https://doi.org/10.1021/acs.est.9b06983
Helmig, D., 2020. Air quality impacts from oil and natural gas development in Colorado. Elem. Sci. Anth. 8, 4. https://doi.org/10.1525/elementa.398
Wang, W., Ganzeveld, L., Rossabi, S., Hueber, J., Helmig, D., 2020. Measurement report: Leaf-scale gas exchange of atmospheric reactive trace species (NO2 , NO, O3 ) at a northern hardwood forest in Michigan. Atmos. Chem. Phys. 20, 11287–11304. https://doi.org/10.5194/acp-20-11287-2020
Helmig, D., Liptzin, D., Hueber, J., Savarino, J., 2020. Impact of exhaust emissions on chemical snowpack composition at Concordia Station, Antarctica. The Cryosphere 14, 199–209. https://doi.org/10.5194/tc-14-199-2020
Pound, R.J., Sherwen, T., Helmig, D., Carpenter, L.J., Evans, M.J., 2020. Influences of oceanic ozone deposition on tropospheric photochemistry. Atmos. Chem. Phys. 20, 4227–4239. https://doi.org/10.5194/acp-20-4227-2020
Howard, D., Agnan, Y., Helmig, D., Yang, Y., Obrist, D., 2020. Environmental controls on ecosystem-scale cold-season methane and carbon dioxide fluxes in an Arctic tundra ecosystem. Biogeosciences 17, 4025–4042. https://doi.org/10.5194/bg-17-4025-2020
Clifton, O.E., Fiore, A.M., Massman, W.J., Baublitz, C.B., Coyle, M., Emberson, L., Fares, S., Farmer, D.K., Gentine, P., Gerosa, G., Guenther, A.B., Helmig, D., Lombardozzi, D.L., Munger, J.W., Patton, E.G., Pusede, S.E., Schwede, D.B., Silva, S.J., Sörgel, M., Steiner, A.L., Tai, A.P.K., 2020. Dry deposition of ozone over land: Processes, measurement, and modeling. Rev. Geophys. 58, e2019RG000670. https://doi.org/10.1029/2019RG000670
2019
Jiskra, M., Sonke, J.E., Agnan, Y., Helmig, D., Obrist, D., 2019. Insights from mercury stable isotopes on terrestrial–atmosphere exchange of Hg(0) in the Arctic tundra. Biogeosciences 16, 4051–4064. https://doi.org/10.5194/bg-16-4051-2019
Tzompa‐Sosa, Z.A., Henderson, B.H., Keller, C.A., Travis, K., Mahieu, E., Franco, B., Estes, M., Helmig, D., Fried, A., Richter, D., Weibring, P., Walega, J., Blake, D.R., Hannigan, J.W., Ortega, I., Conway, S., Strong, K., Fischer, E.V., 2019. Atmospheric implications of large C2 ‐C5 alkane emissions From the U.S. Oil and gas industry. J. Geophys. Res. Atmos. 124, 1148–1169. https://doi.org/10.1029/2018JD028955
Trowbridge, A.M., Stoy, P.C., Adams, H.D., Law, D.J., Breshears, D.D., Helmig, D., Monson, R.K., 2019. Drought supersedes warming in determining volatile and tissue defenses of piñon pine (Pinus edulis). Environ. Res. Lett. 14, 065006. https://doi.org/10.1088/1748-9326/ab1493
Choudoir, M., Rossabi, S., Gebert, M., Helmig, D., Fierer, N., 2019. A phylogenetic and functional perspective on volatile organic compound production by actinobacteria. mSystems 4, e00295-18. https://doi.org/10.1128/mSystems.00295-18
Oltmans, S.J., Cheadle, L.C., Johnson, B.J., Schnell, R.C., Helmig, D., Thompson, A.M., Cullis, P., Hall, E., Jordan, A., Sterling, C., McClure-Begley, A., Sullivan, J.T., McGee, T.J., Wolfe, D., 2019. Boundary layer ozone in the Northern Colorado Front Range in July–August 2014 during FRAPPE and DISCOVER-AQ from vertical profile measurements. Elem. Sci. Anth. 7, 6. https://doi.org/10.1525/elementa.345
2018
Torres, C., Suárez, L., Schmitt, C., Estevan, R., Helmig, D., 2018. Measurement of light absorbing particles in the snow of the Huaytapallana glacier in the central Andes of Peru and their effect on albedo and radiative forcing. Opt. Pura Apl. 51, 1–14. https://doi.org/10.7149/OPA.51.4.51004
McKenzie, L.M., Blair, B., Hughes, J., Allshouse, W.B., Blake, N.J., Helmig, D., Milmoe, P., Halliday, H., Blake, D.R., Adgate, J.L., 2018. Ambient nonmethane hydrocarbon levels along Colorado’s Northern Front Range: Acute and chronic health risks. Environ. Sci. Technol. 52, 4514–4525. https://doi.org/10.1021/acs.est.7b05983
Thompson, R.L., Nisbet, E.G., Pisso, I., Stohl, A., Blake, D., Dlugokencky, E.J., Helmig, D., White, J.W.C., 2018. Variability in atmospheric methane from fossil fuel and microbial sources over the last three decades. Geophys. Res. Lett. 45, 11499-11508. https://doi.org/10.1029/2018GL078127
Helmig, D., Blanchard, B., Hueber, J., 2018. Contrasting behavior of slow and fast photoreactive gases during the August 21, 2017, solar eclipse. Elem. Sci. Anth. 6, 72. https://doi.org/10.1525/elementa.322
Bien, T., Helmig, D., 2018. Changes in summertime ozone in Colorado during 2000–2015. Elem. Sci. Anth. 6, 55. https://doi.org/10.1525/elementa.300
Monks, S.A., Wilson, C., Emmons, L.K., Hannigan, J.W., Helmig, D., Blake, N.J., Blake, D.R., 2018. Using an inverse model to reconcile differences in simulated and observed global ethane concentrations and trends between 2008 and 2014. J. Geophys. Res. Atmos. 123, 11262-11282. https://doi.org/10.1029/2017JD028112
Rossabi, S., Choudoir, M., Helmig, D., Hueber, J., Fierer, N., 2018. Volatile organic compound emissions from soil following wetting events. J. Geophys. Res. Biogeosciences, 123, 1988–2001. https://doi.org/10.1029/2018JG004514
Song, S., Angot, H., Selin, N.E., Gallée, H., Sprovieri, F., Pirrone, N., Helmig, D., Savarino, J., Magand, O., Dommergue, A., 2018. Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: A modeling study. Atmos. Chem. Phys. 18, 15825–15840. https://doi.org/10.5194/acp-18-15825-2018
Agnan, Y., Douglas, T.A., Helmig, D., Hueber, J., Obrist, D., 2018. Mercury in the Arctic tundra snowpack: temporal and spatial concentration patterns and trace gas exchanges. The Cryosphere 12, 1939–1956. https://doi.org/10.5194/tc-12-1939-2018
McKenzie, L.M., Blair, B., Hughes, J., Allshouse, W.B., Blake, N.J., Helmig, D., Milmoe, P., Halliday, H., Blake, D.R., Adgate, J.L., 2018. Ambient nonmethane hydrocarbon levels along Colorado’s Northern Front Range: Acute and chronic health risks. Environ. Sci. Technol. 52, 4514–4525. https://doi.org/10.1021/acs.est.7b05983
Feldman, D.R., Collins, W.D., Biraud, S.C., Risser, M.D., Turner, D.D., Gero, P.J., Tadić, J., Helmig, D., Xie, S., Mlawer, E.J., Shippert, T.R., Torn, M.S., 2018. Observationally derived rise in methane surface forcing mediated by water vapour trends. Nature Geosci. 11, 238–243. https://doi.org/10.1038/s41561-018-0085-9
Rossabi, S., Helmig, D., 2018. Changes in atmospheric butanes and pentanes and their isomeric ratios in the Continental United States. J. Geophys. Res. Atmos. 123, 3772–3790. https://doi.org/10.1002/2017JD027709
Dalsøren, S.B., Myhre, G., Hodnebrog, Ø., Myhre, C.L., Stohl, A., Pisso, I., Schwietzke, S., Höglund-Isaksson, L., Helmig, D., Reimann, S., Sauvage, S., Schmidbauer, N., Read, K.A., Carpenter, L.J., Lewis, A.C., Punjabi, S., Wallasch, M., 2018. Discrepancy between simulated and observed ethane and propanelevels explained by underestimated fossil emissions. Nature Geosci. 11, 178–184. https://doi.org/10.1038/s41561-018-0073-0
2017
Huang, Y., Wu, S., Kramer, L.J., Helmig, D., Honrath, R.E., 2017. Surface ozone and its precursors at Summit, Greenland: comparison between observations and model simulations. Atmos. Chem. Phys. 17, 14661–14674. https://doi.org/10.5194/acp-17-14661-2017
Matichuk, R., Tonnesen, G., Luecken, D., Gilliam, R., Napelenok, S.L., Baker, K.R., Schwede, D., Murphy, B., Helmig, D., Lyman, S.N., Roselle, S., 2017. Evaluation of the Community Multiscale Air Quality Model for simulating winter ozone formation in the Uinta Basin. J. Geophys. Res. Atmos. 122. https://doi.org/10.1002/2017JD027057
Schultz, M.G., Schröder, S., Lyapina, O., Cooper, O.R., Galbally, I., Petropavlovskikh, I., Von Schneidemesser, E., Tanimoto, H., Elshorbany, Y., Naja, M., Seguel, R.J., Dauert, U., Eckhardt, P., Feigenspan, S., Fiebig, M., Hjellbrekke, A.-G., Hong, Y.-D., Kjeld, P.C., Koide, H., Lear, G., Tarasick, D., Ueno, M., Wallasch, M., Baumgardner, D., Chuang, M.-T., Gillett, R., Lee, M., Molloy, S., Moolla, R., Wang, T., Sharps, K., Adame, J.A., Ancellet, G., Apadula, F., Artaxo, P., Barlasina, M.E., Bogucka, M., Bonasoni, P., Chang, L., Colomb, A., Cuevas-Agulló, E., Cupeiro, M., Degorska, A., Ding, A., Fröhlich, M., Frolova, M., Gadhavi, H., Gheusi, F., Gilge, S., Gonzalez, M.Y., Gros, V., Hamad, S.H., Helmig, D., Henriques, D., Hermansen, O., Holla, R., Hueber, J., Im, U., Jaffe, D.A., Komala, N., Kubistin, D., Lam, K.-S., Laurila, T., Lee, H., Levy, I., Mazzoleni, C., Mazzoleni, L.R., McClure-Begley, A., Mohamad, M., Murovec, M., Navarro-Comas, M., Nicodim, F., Parrish, D., Read, K.A., Reid, N., Ries, L., Saxena, P., Schwab, J.J., Scorgie, Y., Senik, I., Simmonds, P., Sinha, V., Skorokhod, A.I., Spain, G., Spangl, W., Spoor, R., Springston, S.R., Steer, K., Steinbacher, M., Suharguniyawan, E., Torre, P., Trickl, T., Weili, L., Weller, R., Xiaobin, X., Xue, L., Zhiqiang, M., 2017. Tropospheric Ozone Assessment Report: Database and metrics data of global surface ozone observations. Elem. Sci. Anth. 5, 58. https://doi.org/10.1525/elementa.244
Obrist, D., Agnan, Y., Jiskra, M., Olson, C.L., Colegrove, D.P., Hueber, J., Moore, C.W., Sonke, J.E., Helmig, D., 2017. Tundra uptake of atmospheric elemental mercury drives Arctic mercury pollution. Nature 547, 201–204. https://doi.org/10.1038/nature22997
Newland, M.J., Martinerie, P., Witrant, E., Helmig, D., Worton, D.R., Hogan, C., Sturges, W.T., Reeves, C.E., 2017. Changes to the chemical state of the Northern Hemisphere atmosphere during the second half of the twentieth century. Atmos. Chem. Phys. 17, 8269–8283. https://doi.org/10.5194/acp-17-8269-2017
Tzompa‐Sosa, Z.A., Mahieu, E., Franco, B., Keller, C.A., Turner, A.J., Helmig, D., Fried, A., Richter, D., Weibring, P., Walega, J., Yacovitch, T.I., Herndon, S.C., Blake, D.R., Hase, F., Hannigan, J.W., Conway, S., Strong, K., Schneider, M., Fischer, E.V., 2017. Revisiting global fossil fuel and biofuel emissions of ethane. J. Geophys. Res. Atmos. 122, 2493–2512. https://doi.org/10.1002/2016JD025767
Zhang, B., Owen, R.C., Perlinger, J.A., Helmig, D., Val Martín, M., Kramer, L., Mazzoleni, L.R., Mazzoleni, C., 2017. Ten-year chemical signatures associated with long-range transport observed in the free troposphere over the central North Atlantic. Elem. Sci. Anth. 5, 8. https://doi.org/10.1525/elementa.194
Evans, J.M., Helmig, D., 2017. Investigation of the influence of transport from oil and natural gas regions on elevated ozone levels in the Northern Colorado Front Range. J. Air Waste Manag. Assoc. 67, 196–211. https://doi.org/10.1080/10962247.2016.1226989
2016
Oltmans, S.J., Karion, A., Schnell, R.C., Pétron, G., Helmig, D., Montzka, S.A., Wolter, S., Neff, D., Miller, B.R., Hueber, J., Conley, S., Johnson, B.J., Sweeney, C., 2016. O3, CH4, CO2, CO, NO2 and NMHC aircraft measurements in the Uinta Basin oil and gas region under low and high ozone conditions in winter 2012 and 2013. Elem. Sci. Anth. 4, 000132. https://doi.org/10.12952/journal.elementa.000132
Pollmann, J., Helmig, D., Liptzin, D., Thompson, C.R., Hueber, J., Tans, P.P., Lelieveld, J., 2016. Variability analyses, site characterization, and regional [OH] estimates using trace gas measurements from the NOAA Global Greenhouse Gas Reference Network. Elem. Sci. Anth. 4, 000128. https://doi.org/10.12952/journal.elementa.000128
Schnell, R.C., Johnson, B.J., Oltmans, S.J., Cullis, P., Sterling, C., Hall, E., Jordan, A., Helmig, D., Petron, G., Ahmadov, R., Wendell, J., Albee, R., Boylan, P., Thompson, C.R., Evans, J., Hueber, J., Curtis, A.J., Park, J., 2016. Quantifying wintertime boundary layer ozone production from frequent profile measurements in the Uinta Basin, UT, oil and gas region. J. Geophys. Res. Atmos. 121. https://doi.org/10.1002/2016JD025130
Angot, H., Magand, O., Helmig, D., Ricaud, P., Quennehen, B., Gallée, H., Del Guasta, M., Sprovieri, F., Pirrone, N., Savarino, J., Dommergue, A., 2016. New insights into the atmospheric mercury cycling in central Antarctica and implications on a continental scale. Atmos. Chem. Phys. 16, 8249–8264. https://doi.org/10.5194/acp-16-8249-2016
Helmig, D., Rossabi, S., Hueber, J., Tans, P., Montzka, S.A., Masarie, K., Thoning, K., Plass-Duelmer, C., Claude, A., Carpenter, L.J., Lewis, A.C., Punjabi, S., Reimann, S., Vollmer, M.K., Steinbrecher, R., Hannigan, J.W., Emmons, L.K., Mahieu, E., Franco, B., Smale, D., Pozzer, A., 2016. Reversal of global atmospheric ethane and propane trends largely due to US oil and natural gas production. Nat. Geosci. 9, 490–495. https://doi.org/10.1038/ngeo2721
Legrand, M., Preunkert, S., Savarino, J., Frey, M.M., Kukui, A., Helmig, D., Jourdain, B., Jones, A.E., Weller, R., Brough, N., Gallée, H., 2016. Inter-annual variability of surface ozone at coastal (Dumont d’Urville, 2004–2014) and inland (Concordia, 2007–2014) sites in East Antarctica. Atmos. Chem. Phys. 16, 8053–8069. https://doi.org/10.5194/acp-16-8053-2016
Van Dam, B., Helmig, D., Doskey, P.V., Oltmans, S.J., 2016. Summertime surface O3 behavior and deposition to tundra in the Alaskan Arctic. J. Geophys. Res. Atmos. 121, 8055–8066. https://doi.org/10.1002/2015JD023914
2015
Kramer, L.J., Helmig, D., Burkhart, J.F., Stohl, A., Oltmans, S., Honrath, R.E., 2015. Seasonal variability of atmospheric nitrogen oxides and non-methane hydrocarbons at the GEOSummit station, Greenland. Atmos. Chem. Phys. 15, 6827–6849. https://doi.org/10.5194/acp-15-6827-2015
Van Dam, B., Helmig, D., Toro, C., Doskey, P., Kramer, L., Murray, K., Ganzeveld, L., Seok, B., 2015. Dynamics of ozone and nitrogen oxides at Summit, Greenland: I. multi-year observations in the snowpack. Atmos. Environ. 123, 268–284. https://doi.org/10.1016/j.atmosenv.2015.09.060
Schultz, M.G., Akimoto, H., Bottenheim, J., Buchmann, B., Galbally, I.E., Gilge, S., Helmig, D., Koide, H., Lewis, A.C., Novelli, P.C., Plass-Dülmer, C., Ryerson, T.B., Steinbacher, M., Steinbrecher, R., Tarasova, O., Tørseth, K., Thouret, V., Zellweger, C., 2015. The Global Atmosphere Watch reactive gases measurement network. Elem. Sci. Anth. 3, 000067. https://doi.org/10.12952/journal.elementa.000067
Murray, K.A., Kramer, L.J., Doskey, P.V., Ganzeveld, L., Seok, B., Van Dam, B., Helmig, D., 2015. Dynamics of ozone and nitrogen oxides at Summit, Greenland. II. Simulating snowpack chemistry during a spring high ozone event with a 1-D process-scale model. Atmos. Environ. 117, 110–123. https://doi.org/10.1016/j.atmosenv.2015.07.004
Liptzin, D., Helmig, D., Schmidt, S.K., Seok, B., Williams, M.W., 2015. Winter gas exchange between the atmosphere and snow-covered soils on Niwot Ridge, Colorado, USA. Plant Ecol. Divers. 8, 677–688. https://doi.org/10.1080/17550874.2015.1065925
Helmig, D., Muñoz, M., Hueber, J., Mazzoleni, C., Mazzoleni, L., Owen, R.C., Val-Martin, M., Fialho, P., Plass-Duelmer, C., Palmer, P.I., Lewis, A.C., Pfister, G., 2015. Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic. Elem. Sci. Anth. 3, 000054. https://doi.org/10.12952/journal.elementa.000054
Gray, C.M., Helmig, D., Fierer, N., 2015. Bacteria and fungi associated with isoprene consumption in soil. Elem. Sci. Anth. 3, 000053. https://doi.org/10.12952/journal.elementa.000053
Hu, L., Millet, D.B., Baasandorj, M., Griffis, T.J., Turner, P., Helmig, D., Curtis, A.J., Hueber, J., 2015. Isoprene emissions and impacts over an ecological transition region in the U.S. Upper Midwest inferred from tall tower measurements. J. Geophys. Res. Atmos. 120, 3553–3571. https://doi.org/10.1002/2014JD022732
Preunkert, S., Legrand, M., Frey, M.M., Kukui, A., Savarino, J., Gallée, H., King, M., Jourdain, B., Vicars, W., Helmig, D., 2015. Formaldehyde (HCHO) in air, snow, and interstitial air at Concordia (East Antarctic Plateau) in summer. Atmos. Chem. Phys. 15, 6689–6705. https://doi.org/10.5194/acp-15-6689-2015
Boylan, P., Helmig, D., Oltmans, S., 2015. Ozone in the Atlantic Ocean marine boundary layer. Elem. Sci. Anth. 3, 000045. https://doi.org/10.12952/journal.elementa.000045
Dzepina, K., Mazzoleni, C., Fialho, P., China, S., Zhang, B., Owen, R.C., Helmig, D., Hueber, J., Kumar, S., Perlinger, J.A., Kramer, L.J., Dziobak, M.P., Ampadu, M.T., Olsen, S., Wuebbles, D.J., Mazzoleni, L.R., 2015. Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory: A case study with a long-range transported biomass burning plume. Atmos. Chem. Phys. 15, 5047–5068. https://doi.org/10.5194/acp-15-5047-2015
Seok, B., Helmig, D., Liptzin, D., Williams, M.W., Vogel, C.S., 2015. Snowpack-atmosphere gas exchanges of carbon dioxide, ozone, and nitrogen oxides at a hardwood forest site in northern Michigan. Elem. Sci. Anth. 3, 000040. https://doi.org/10.12952/journal.elementa.000040
China, S., Scarnato, B., Owen, R.C., Zhang, B., Ampadu, M.T., Kumar, S., Dzepina, K., Dziobak, M.P., Fialho, P., Perlinger, J.A., Hueber, J., Helmig, D., Mazzoleni, L.R., Mazzoleni, C., 2015. Morphology and mixing state of aged soot particles at a remote marine free troposphere site: Implications for optical properties. Geophys. Res. Lett. 42, 1243–1250. https://doi.org/10.1002/2014GL062404
Lawson, S.J., Selleck, P.W., Galbally, I.E., Keywood, M.D., Harvey, M.J., Lerot, C., Helmig, D., Ristovski, Z., 2015. Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere. Atmos. Chem. Phys. 15, 223–240. https://doi.org/10.5194/acp-15-223-2015
Emmons, L.K., Arnold, S.R., Monks, S.A., Huijnen, V., Tilmes, S., Law, K.S., Thomas, J.L., Raut, J.-C., Bouarar, I., Turquety, S., Long, Y., Duncan, B., Steenrod, S., Strode, S., Flemming, J., Mao, J., Langner, J., Thompson, A.M., Tarasick, D., Apel, E.C., Blake, D.R., Cohen, R.C., Dibb, J., Diskin, G.S., Fried, A., Hall, S.R., Huey, L.G., Weinheimer, A.J., Wisthaler, A., Mikoviny, T., Nowak, J., Peischl, J., Roberts, J.M., Ryerson, T., Warneke, C., Helmig, D., 2015. The POLARCAT Model Intercomparison Project (POLMIP): Overview and evaluation with observations. Atmos. Chem. Phys. 15, 6721–6744. https://doi.org/10.5194/acp-15-6721-2015
Ahmadov, R., McKeen, S., Trainer, M., Banta, R., Brewer, A., Brown, S., Edwards, P.M., De Gouw, J.A., Frost, G.J., Gilman, J., Helmig, D., Johnson, B., Karion, A., Koss, A., Langford, A., Lerner, B., Olson, J., Oltmans, S., Peischl, J., Pétron, G., Pichugina, Y., Roberts, J.M., Ryerson, T., Schnell, R., Senff, C., Sweeney, C., Thompson, C., Veres, P.R., Warneke, C., Wild, R., Williams, E.J., Yuan, B., Zamora, R., 2015. Understanding high wintertime ozone pollution events in an oil- and natural gas-producing region of the western US. Atmos. Chem. Phys. 15, 411–429. https://doi.org/10.5194/acp-15-411-2015
2014
Thompson, C.R., Hueber, J., Helmig, D., 2014. Influence of oil and gas emissions on ambient atmospheric non-methane hydrocarbons in residential areas of Northeastern Colorado. Elem. Sci. Anth. 3, 000035. https://doi.org/10.12952/journal.elementa.000035
Edwards, P.M., Brown, S.S., Roberts, J.M., Ahmadov, R., Banta, R.M., deGouw, J.A., Dubé, W.P., Field, R.A., Flynn, J.H., Gilman, J.B., Graus, M., Helmig, D., Koss, A., Langford, A.O., Lefer, B.L., Lerner, B.M., Li, R., Li, S.-M., McKeen, S.A., Murphy, S.M., Parrish, D.D., Senff, C.J., Soltis, J., Stutz, J., Sweeney, C., Thompson, C.R., Trainer, M.K., Tsai, C., Veres, P.R., Washenfelder, R.A., Warneke, C., Wild, R.J., Young, C.J., Yuan, B., Zamora, R., 2014. High winter ozone pollution from carbonyl photolysis in an oil and gas basin. Nature 514, 351–354. https://doi.org/10.1038/nature13767
Oltmans, S.J., Karion, A., Schnell, R.C., Pétron, G., Sweeney, C., Wolter, S., Neff, D., Montzka, S.A., Miller, B.R., Helmig, D., Johnson, B.J., Hueber, J., 2014. A high ozone episode in winter 2013 in the Uinta Basin oil and gas region characterized by aircraft measurements. Atmos. Chem. Phys. Discuss. 14, 20117-20157. https://doi.org/10.5194/acpd-14-20117-2014
Trowbridge, A.M., Daly, R.W., Helmig, D., Stoy, P.C., Monson, R.K., 2014. Herbivory and climate interact serially to control monoterpene emissions from pinyon pine forests. Ecology 95, 1591–1603. https://doi.org/10.1890/13-0989.1
Curtis, A.J., Helmig, D., Baroch, C., Daly, R., Davis, S., 2014. Biogenic volatile organic compound emissions from nine tree species used in an urban tree-planting program. Atmos. Environ. 95, 634–643. https://doi.org/10.1016/j.atmosenv.2014.06.035
Boylan, P., Helmig, D., Park, J.-H., 2014. Characterization and mitigation of water vapor effects in the measurement of ozone by chemiluminescence with nitric oxide. Atmos. Meas. Tech. 7, 1231–1244. https://doi.org/10.5194/amt-7-1231-2014
Pétron, G., Karion, A., Sweeney, C., Miller, B.R., Montzka, S.A., Frost, G.J., Trainer, M., Tans, P., Andrews, A., Kofler, J., Helmig, D., Guenther, D., Dlugokencky, E., Lang, P., Newberger, T., Wolter, S., Hall, B., Novelli, P., Brewer, A., Conley, S., Hardesty, M., Banta, R., White, A., Noone, D., Wolfe, D., Schnell, R., 2014. A new look at methane and nonmethane hydrocarbon emissions from oil and natural gas operations in the Colorado Denver‐Julesburg Basin. J. Geophys. Res. Atmos. 119, 6836–6852. https://doi.org/10.1002/2013JD021272
Rhoderick, G.C., Duewer, D.L., Apel, E., Baldan, A., Hall, B., Harling, A., Helmig, D., Heo, G.S., Hueber, J., Kim, M.E., Kim, Y.D., Miller, B., Montzka, S., Riemer, D., 2014. International comparison of a hydrocarbon gas standard at the picomol per mol level. Anal. Chem. 86, 2580–2589. https://doi.org/10.1021/ac403761u
Helmig, D., Petrenko, V., Martinerie, P., Witrant, E., Röckmann, T., Zuiderweg, A., Holzinger, R., Hueber, J., Thompson, C., White, J.W.C., Sturges, W., Baker, A., Blunier, T., Etheridge, D., Rubino, M., Tans, P., 2014. Reconstruction of Northern Hemisphere 1950–2010 atmospheric non-methane hydrocarbons. Atmos. Chem. Phys. 14, 1463–1483. https://doi.org/10.5194/acp-14-1463-2014
Helmig, D., Thompson, C.R., Evans, J., Boylan, P., Hueber, J., Park, J.-H., 2014. Highly elevated atmospheric levels of volatile organic compounds in the Uintah Basin, Utah. Environ. Sci. Technol. 48, 4707–4715. https://doi.org/10.1021/es405046r
Boylan, P., Helmig, D., Staebler, R., Turnipseed, A., Fairall, C., Neff, W., 2014. Boundary layer dynamics during the Ocean‐Atmosphere‐Sea‐Ice‐Snow (OASIS) 2009 experiment at Barrow, AK. J. Geophys. Res. Atmos. 119, 2261–2278. https://doi.org/10.1002/2013JD020299
Zhang, B., Owen, R.C., Perlinger, J.A., Kumar, A., Wu, S., Val Martin, M., Kramer, L., Helmig, D., Honrath, R.E., 2014. A semi-Lagrangian view of ozone production tendency in North American outflow in the summers of 2009 and 2010. Atmos. Chem. Phys. 14, 2267–2287. https://doi.org/10.5194/acp-14-2267-2014
2013
Helmig, D., Stephens, C.R., Caramore, J., Hueber, J., 2014. Seasonal behavior of non-methane hydrocarbons in the firn air at Summit, Greenland. Atmos. Environ. 85, 234–246. https://doi.org/10.1016/j.atmosenv.2013.11.021
Faïn, X., Helmig, D., Hueber, J., Obrist, D., Williams, M.W., 2013. Mercury dynamics in the Rocky Mountain, Colorado, snowpack. Biogeosciences 10, 3793–3807. https://doi.org/10.5194/bg-10-3793-2013
Kumar, A., Wu, S., Weise, M.F., Honrath, R., Owen, R.C., Helmig, D., Kramer, L., Val Martin, M., Li, Q., 2013. Free-troposphere ozone and carbon monoxide over the North Atlantic for 2001–2011. Atmos. Chem. Phys. 13, 12537–12547. https://doi.org/10.5194/acp-13-12537-2013
Van Dam, B., Helmig, D., Neff, W., Kramer, L., 2013. Evaluation of boundary layer depth estimates at Summit Station, Greenland. J. Appl. Meteorol. Climatol. 52, 2356–2362. https://doi.org/10.1175/JAMC-D-13-055.1
Helmig, D., Daly, R.W., Milford, J., Guenther, A., 2013. Seasonal trends of biogenic terpene emissions. Chemosphere 93, 35–46. https://doi.org/10.1016/j.chemosphere.2013.04.058
Edwards, P.M., Young, C.J., Aikin, K., deGouw, J., Dubé, W.P., Geiger, F., Gilman, J., Helmig, D., Holloway, J.S., Kercher, J., Lerner, B., Martin, R., McLaren, R., Parrish, D.D., Peischl, J., Roberts, J.M., Ryerson, T.B., Thornton, J., Warneke, C., Williams, E.J., Brown, S.S., 2013. Ozone photochemistry in an oil and natural gas extraction region during winter: Simulations of a snow-free season in the Uintah Basin, Utah. Atmos. Chem. Phys. 13, 8955–8971. https://doi.org/10.5194/acp-13-8955-2013
Seok, B., Helmig, D., Ganzeveld, L., Williams, M.W., Vogel, C.S., 2013. Dynamics of nitrogen oxides and ozone above and within a mixed hardwood forest in northern Michigan. Atmos. Chem. Phys. 13, 7301–7320. https://doi.org/10.5194/acp-13-7301-2013
Hu, L., Millet, D.B., Kim, S.Y., Wells, K.C., Griffis, T.J., Fischer, E.V., Helmig, D., Hueber, J., Curtis, A.J., 2013. North American acetone sources determined from tall tower measurements and inverse modeling. Atmos. Chem. Phys. 13, 3379–3392. https://doi.org/10.5194/acp-13-3379-2013
Palmer, P.I., Parrington, M., Lee, J.D., Lewis, A.C., Rickard, A.R., Bernath, P.F., Duck, T.J., Waugh, D.L., Tarasick, D.W., Andrews, S., Aruffo, E., Bailey, L.J., Barrett, E., Bauguitte, S.J.-B., Curry, K.R., Di Carlo, P., Chisholm, L., Dan, L., Forster, G., Franklin, J.E., Gibson, M.D., Griffin, D., Helmig, D., Hopkins, J.R., Hopper, J.T., Jenkin, M.E., Kindred, D., Kliever, J., Le Breton, M., Matthiesen, S., Maurice, M., Moller, S., Moore, D.P., Oram, D.E., O’Shea, S.J., Owen, R.C., Pagniello, C.M.L.S., Pawson, S., Percival, C.J., Pierce, J.R., Punjabi, S., Purvis, R.M., Remedios, J.J., Rotermund, K.M., Sakamoto, K.M., Da Silva, A.M., Strawbridge, K.B., Strong, K., Taylor, J., Trigwell, R., Tereszchuk, K.A., Walker, K.A., Weaver, D., Whaley, C., Young, J.C., 2013. Quantifying the impact of BOReal forest fires on tropospheric oxidants over the Atlantic using aircraft and satellites (BORTAS) experiment: Design, execution and science overview. Atmos. Chem. Phys. 13, 6239–6261. https://doi.org/10.5194/acp-13-6239-2013
Van Dam, B., Helmig, D., Burkhart, J.F., Obrist, D., Oltmans, S.J., 2013. Springtime boundary layer O3 and GEM depletion at Toolik Lake, Alaska. J. Geophys. Res. Atmos. 118, 3382–3391. https://doi.org/10.1002/jgrd.50213
2012
Helmig, D., Boylan, P., Johnson, B., Oltmans, S., Fairall, C., Staebler, R., Weinheimer, A., Orlando, J., Knapp, D.J., Montzka, D.D., Flocke, F., Frieß, U., Sihler, H., Shepson, P.B., 2012. Ozone dynamics and snow‐atmosphere exchanges during ozone depletion events at Barrow, Alaska. J. Geophys. Res. 117, 2012JD017531. https://doi.org/10.1029/2012JD017531
Pratt, K.A., Mielke, L.H., Shepson, P.B., Bryan, A.M., Steiner, A.L., Ortega, J., Daly, R., Helmig, D., Vogel, C.S., Griffith, S., Dusanter, S., Stevens, P.S., Alaghmand, M., 2012. Contributions of individual reactive biogenic volatile organic compounds to organic nitrates above a mixed forest. Atmos. Chem. Phys. 12, 10125–10143. https://doi.org/10.5194/acp-12-10125-2012
Bryan, A.M., Bertman, S.B., Carroll, M.A., Dusanter, S., Edwards, G.D., Forkel, R., Griffith, S., Guenther, A.B., Hansen, R.F., Helmig, D., Jobson, B.T., Keutsch, F.N., Lefer, B.L., Pressley, S.N., Shepson, P.B., Stevens, P.S., Steiner, A.L., 2012. In-canopy gas-phase chemistry during CABINEX 2009: Sensitivity of a 1-D canopy model to vertical mixing and isoprene chemistry. Atmos. Chem. Phys. 12, 8829–8849. https://doi.org/10.5194/acp-12-8829-2012
Simpson, I.J., Sulbaek Andersen, M.P., Meinardi, S., Bruhwiler, L., Blake, N.J., Helmig, D., Rowland, F.S., Blake, D.R., 2012. Long-term decline of global atmospheric ethane concentrations and implications for methane. Nature 488, 490–494. https://doi.org/10.1038/nature11342
Van Dam, B., Helmig, D., 2012. Comments on 'Possible contribution of triboelectricity to snow - air interactions'. Environ. Chem. 9, 116. https://doi.org/10.1071/EN11151
Helmig, D., Lang, E.K., Bariteau, L., Boylan, P., Fairall, C.W., Ganzeveld, L., Hare, J.E., Hueber, J., Pallandt, M., 2012. Atmosphere‐ocean ozone fluxes during the TexAQS 2006, STRATUS 2006, GOMECC 2007, GasEx 2008, and AMMA 2008 cruises. J. Geophys. Res. 117, 2011JD015955. https://doi.org/10.1029/2011JD015955
Baghi, R., Helmig, D., Guenther, A., Duhl, T., Daly, R., 2012. Contribution of flowering trees to urban atmospheric biogenic volatile organic compound emissions. Biogeosciences 9, 3777–3785. https://doi.org/10.5194/bg-9-3777-2012
Parrington, M., Palmer, P.I., Henze, D.K., Tarasick, D.W., Hyer, E.J., Owen, R.C., Helmig, D., Clerbaux, C., Bowman, K.W., Deeter, M.N., Barratt, E.M., Coheur, P.-F., Hurtmans, D., Jiang, Z., George, M., Worden, J.R., 2012. The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010. Atmos. Chem. Phys. 12, 2077–2098. https://doi.org/10.5194/acp-12-2077-2012
2011
Fairall, C.W., Yang, M., Bariteau, L., Edson, J.B., Helmig, D., McGillis, W., Pezoa, S., Hare, J.E., Huebert, B., Blomquist, B., 2011. Implementation of the coupled ocean-atmosphere response experiment flux algorithm with CO2, dimethyl sulfide, and O3. J. Geophys. Res. 116, C00F09. https://doi.org/10.1029/2010JC006884
Edson, J.B., Fairall, C.W., Bariteau, L., Zappa, C.J., Cifuentes-Lorenzen, A., McGillis, W.R., Pezoa, S., Hare, J.E., Helmig, D., 2011. Direct covariance measurement of CO2 gas transfer velocity during the 2008 Southern Ocean Gas Exchange Experiment: Wind speed dependency. J. Geophys. Res. 116, C00F10. https://doi.org/10.1029/2011JC007022
Brodin, M., Helmig, D., Johnson, B., Oltmans, S., 2011. Comparison of ozone concentrations on a surface elevation gradient with balloon-borne ozonesonde measurements. Atmos. Environ. 45, 5431–5439. https://doi.org/10.1016/j.atmosenv.2011.07.002
Grachev, A.A., Bariteau, L., Fairall, C.W., Hare, J.E., Helmig, D., Hueber, J., Lang, E.K., 2011. Turbulent fluxes and transfer of trace gases from ship-based measurements during TexAQS 2006. J. Geophys. Res. 116, D13110. https://doi.org/10.1029/2010JD015502
Hu, L., Millet, D.B., Mohr, M.J., Wells, K.C., Griffis, T.J., Helmig, D., 2011. Sources and seasonality of atmospheric methanol based on tall tower measurements in the US Upper Midwest. Atmos. Chem. Phys. 11, 11145–11156. https://doi.org/10.5194/acp-11-11145-2011
Bocquet, F., Helmig, D., Van Dam, B.A., Fairall, C.W., 2011. Evaluation of the flux gradient technique for measurement of ozone surface fluxes over snowpack at Summit, Greenland. Atmos. Meas. Tech. 4, 2305–2321. https://doi.org/10.5194/amt-4-2305-2011
Duhl, T.R., Guenther, A., Helmig, D., 2012. Estimating urban vegetation cover fraction using Google Earth® images. J. Land Use Sci. 7, 311–329. https://doi.org/10.1080/1747423X.2011.587207
2010
Bariteau, L., Helmig, D., Fairall, C.W., Hare, J.E., Hueber, J., Lang, E.K., 2010. Determination of oceanic ozone deposition by ship-borne eddy covariance flux measurements. Atmos. Meas. Tech. 3, 441–455. https://doi.org/10.5194/amt-3-441-2010
Brodin, M., Helmig, D., Oltmans, S., 2010. Seasonal ozone behavior along an elevation gradient in the Colorado Front Range Mountains. Atmos. Environ. 44, 5305–5315. https://doi.org/10.1016/j.atmosenv.2010.06.033
Pozzer, A., Pollmann, J., Taraborrelli, D., Jöckel, P., Helmig, D., Tans, P., Hueber, J., Lelieveld, J., 2010. Observed and simulated global distribution and budget of atmospheric C2 -C5 alkanes. Atmos. Chem. Phys. 10, 4403–4422. https://doi.org/10.5194/acp-10-4403-2010