1
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Long MC, Stephens BB, McKain K, Sweeney C, Keeling RF, Kort EA, Morgan EJ, Bent JD, Chandra N, Chevallier F, Commane R, Daube BC, Krummel PB, Loh Z, Luijkx IT, Munro D, Patra P, Peters W, Ramonet M, Rödenbeck C, Stavert A, Tans P, Wofsy SC. Strong Southern Ocean carbon uptake evident in airborne observations. Science 2021; 374:1275-1280. [PMID: 34855495 DOI: 10.1126/science.abi4355] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Matthew C Long
- National Center for Atmospheric Research, Boulder, CO, USA
| | | | - Kathryn McKain
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA.,Global Monitoring Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
| | - Colm Sweeney
- Global Monitoring Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
| | - Ralph F Keeling
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA
| | - Eric A Kort
- Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Eric J Morgan
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA
| | - Jonathan D Bent
- National Center for Atmospheric Research, Boulder, CO, USA.,Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA
| | - Naveen Chandra
- National Institute of Environmental Studies, Tsukuba, Japan
| | - Frederic Chevallier
- Laboratoire des Sciences du Climat et de l'Environnement, IPSL-LSCE, CEA-CNRS-UVSQ, UMR8212 91191, France
| | - Róisín Commane
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - Bruce C Daube
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA
| | - Paul B Krummel
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, Victoria, Australia
| | - Zoë Loh
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, Victoria, Australia
| | - Ingrid T Luijkx
- Department of Meteorology and Air Quality, Environmental Sciences Group, Wageningen University, Netherlands
| | - David Munro
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA.,Global Monitoring Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
| | - Prabir Patra
- Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Japan
| | - Wouter Peters
- Department of Meteorology and Air Quality, Environmental Sciences Group, Wageningen University, Netherlands.,Centre for Isotope Research, University of Groningen, Groningen, Netherlands
| | - Michel Ramonet
- Laboratoire des Sciences du Climat et de l'Environnement, IPSL-LSCE, CEA-CNRS-UVSQ, UMR8212 91191, France
| | | | - Ann Stavert
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, Victoria, Australia
| | - Pieter Tans
- Global Monitoring Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
| | - Steven C Wofsy
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA.,Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
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2
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Towards a Fast, Open-Path Laser Hygrometer for Airborne Eddy Covariance Measurements. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11115189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Water vapor fluxes play a key role in the energy budget of the atmosphere, and better flux measurements are needed to improve our understanding of the formation of clouds and storms. Large-scale measurements of these fluxes are possible by employing the eddy correlation (EC) method from an aircraft. A hygrometer used for such measurements needs to deliver a temporal resolution of at least 10 Hz while reliably operating in the harsh conditions on the exterior of an aircraft. Here, we present a design concept for a calibration-free, first-principles, open-path dTDLAS hygrometer with a planar, circular and rotationally symmetric multipass cell with new, angled coupling optics. From our measurements, the uncertainty of the instrument is estimated to be below 4.5% (coverage factor k = 1). A static intercomparison between a dTDLAS prototype of the new optics setup and a traceable dew point mirror hygrometer was conducted and showed a systematic relative deviation of 2.6% with a maximal relative error of 2.2%. Combined with a precision of around 1 ppm H2O at tropospheric conditions, the newly designed setup fulfills the static precision and accuracy requirements of the proposed airborne EC hygrometer.
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3
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Anderson DC, Nicely JM, Wolfe GM, Hanisco TF, Salawitch RJ, Canty TP, Dickerson RR, Apel EC, Baidar S, Bannan TJ, Blake NJ, Chen D, Dix B, Fernandez RP, Hall SR, Hornbrook RS, Huey LG, Josse B, Jöckel P, Kinnison DE, Koenig TK, LeBreton M, Marécal V, Morgenstern O, Oman LD, Pan LL, Percival C, Plummer D, Revell LE, Rozanov E, Saiz-Lopez A, Stenke A, Sudo K, Tilmes S, Ullmann K, Volkamer R, Weinheimer AJ, Zeng G. Formaldehyde in the Tropical Western Pacific: Chemical sources and sinks, convective transport, and representation in CAM-Chem and the CCMI models. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2017. [PMID: 29527424 DOI: 10.1002/2017ja024474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Formaldehyde (HCHO) directly affects the atmospheric oxidative capacity through its effects on HOx. In remote marine environments, such as the Tropical Western Pacific (TWP), it is particularly important to understand the processes controlling the abundance of HCHO because model output from these regions is used to correct satellite retrievals of HCHO. Here, we have used observations from the CONTRAST field campaign, conducted during January and February 2014, to evaluate our understanding of the processes controlling the distribution of HCHO in the TWP as well as its representation in chemical transport/climate models. Observed HCHO mixing ratios varied from ~500 pptv near the surface to ~75 pptv in the upper troposphere. Recent convective transport of near surface HCHO and its precursors, acetaldehyde and possibly methyl hydroperoxide, increased upper tropospheric HCHO mixing ratios by ~33% (22 pptv); this air contained roughly 60% less NO than more aged air. Output from the CAM-Chem chemistry transport model (2014 meteorology) as well as nine chemistry climate models from the Chemistry-Climate Model Initiative (free-running meteorology) are found to uniformly underestimate HCHO columns derived from in situ observations by between 4 and 50%. This underestimate of HCHO likely results from a near factor of two underestimate of NO in most models, which strongly suggests errors in NOx emissions inventories and/or in the model chemical mechanisms. Likewise, the lack of oceanic acetaldehyde emissions and potential errors in the model acetaldehyde chemistry lead to additional underestimates in modeled HCHO of up to 75 pptv (~15%) in the lower troposphere.
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Affiliation(s)
- Daniel C Anderson
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
| | - Julie M Nicely
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Universities Space Research Association, Columbia, Maryland, USA
| | - Glenn M Wolfe
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Thomas F Hanisco
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Ross J Salawitch
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
- Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, USA
| | - Timothy P Canty
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
| | - Russell R Dickerson
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
| | - Eric C Apel
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Sunil Baidar
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, Colorado, USA
| | | | - Nicola J Blake
- Department of Chemistry, University of California, Irvine, California, USA
| | - Dexian Chen
- School of Earth & Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Barbara Dix
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA
| | - Rafael P Fernandez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
- Department of Natural Science, National Research Council (CONICET), FCEN-UNCuyo, Mendoza, Argentina
| | - Samuel R Hall
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | | | - L Gregory Huey
- School of Earth & Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Beatrice Josse
- Centre National de Recherche Météorologique, UMR3589, Méteo-France-CNRS, Toulouse, France
| | - Patrick Jöckel
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
| | | | - Theodore K Koenig
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, Colorado, USA
| | - Michael LeBreton
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Virginie Marécal
- Centre National de Recherche Météorologique, UMR3589, Méteo-France-CNRS, Toulouse, France
| | - Olaf Morgenstern
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
| | - Luke D Oman
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Laura L Pan
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Carl Percival
- Department of Chemistry, University of Manchester, UK
| | - David Plummer
- Canadian Centre for Climate Modeling and Analysis, Environment Canada, Victoria, British Columbia, Canada
| | - Laura E Revell
- Bodeker Scientific, Alexandra, New Zealand
- ETH Zürich, Institute for Atmospheric and Climate Science, Zürich, Switzerland
| | - Eugene Rozanov
- ETH Zürich, Institute for Atmospheric and Climate Science, Zürich, Switzerland
- Physikalisch-Meteorologisches Observatorium Davos World Radiation Centre, Davos Dorf, Switzerland
| | - Alfonso Saiz-Lopez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
| | - Andrea Stenke
- ETH Zürich, Institute for Atmospheric and Climate Science, Zürich, Switzerland
| | - Kengo Sudo
- Nagoya University, Graduate School of Environmental Studies, Nagoya, Japan
- Japan Marine-Earth Science and Technology, Yokohama, Japan
| | - Simone Tilmes
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Kirk Ullmann
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Rainer Volkamer
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, Colorado, USA
| | | | - Guang Zeng
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
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4
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Anderson DC, Nicely JM, Wolfe GM, Hanisco TF, Salawitch RJ, Canty TP, Dickerson RR, Apel EC, Baidar S, Bannan TJ, Blake NJ, Chen D, Dix B, Fernandez RP, Hall SR, Hornbrook RS, Huey LG, Josse B, Jöckel P, Kinnison DE, Koenig TK, LeBreton M, Marécal V, Morgenstern O, Oman LD, Pan LL, Percival C, Plummer D, Revell LE, Rozanov E, Saiz-Lopez A, Stenke A, Sudo K, Tilmes S, Ullmann K, Volkamer R, Weinheimer AJ, Zeng G. Formaldehyde in the Tropical Western Pacific: Chemical sources and sinks, convective transport, and representation in CAM-Chem and the CCMI models. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2017; 122:11201-11226. [PMID: 29527424 PMCID: PMC5839129 DOI: 10.1002/2016jd026121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Formaldehyde (HCHO) directly affects the atmospheric oxidative capacity through its effects on HOx. In remote marine environments, such as the Tropical Western Pacific (TWP), it is particularly important to understand the processes controlling the abundance of HCHO because model output from these regions is used to correct satellite retrievals of HCHO. Here, we have used observations from the CONTRAST field campaign, conducted during January and February 2014, to evaluate our understanding of the processes controlling the distribution of HCHO in the TWP as well as its representation in chemical transport/climate models. Observed HCHO mixing ratios varied from ~500 pptv near the surface to ~75 pptv in the upper troposphere. Recent convective transport of near surface HCHO and its precursors, acetaldehyde and possibly methyl hydroperoxide, increased upper tropospheric HCHO mixing ratios by ~33% (22 pptv); this air contained roughly 60% less NO than more aged air. Output from the CAM-Chem chemistry transport model (2014 meteorology) as well as nine chemistry climate models from the Chemistry-Climate Model Initiative (free-running meteorology) are found to uniformly underestimate HCHO columns derived from in situ observations by between 4 and 50%. This underestimate of HCHO likely results from a near factor of two underestimate of NO in most models, which strongly suggests errors in NOx emissions inventories and/or in the model chemical mechanisms. Likewise, the lack of oceanic acetaldehyde emissions and potential errors in the model acetaldehyde chemistry lead to additional underestimates in modeled HCHO of up to 75 pptv (~15%) in the lower troposphere.
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Affiliation(s)
- Daniel C Anderson
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
| | - Julie M Nicely
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Universities Space Research Association, Columbia, Maryland, USA
| | - Glenn M Wolfe
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Thomas F Hanisco
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Ross J Salawitch
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
- Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, USA
| | - Timothy P Canty
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
| | - Russell R Dickerson
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
| | - Eric C Apel
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Sunil Baidar
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, Colorado, USA
| | | | - Nicola J Blake
- Department of Chemistry, University of California, Irvine, California, USA
| | - Dexian Chen
- School of Earth & Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Barbara Dix
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA
| | - Rafael P Fernandez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
- Department of Natural Science, National Research Council (CONICET), FCEN-UNCuyo, Mendoza, Argentina
| | - Samuel R Hall
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | | | - L Gregory Huey
- School of Earth & Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Beatrice Josse
- Centre National de Recherche Météorologique, UMR3589, Méteo-France-CNRS, Toulouse, France
| | - Patrick Jöckel
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
| | | | - Theodore K Koenig
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, Colorado, USA
| | - Michael LeBreton
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Virginie Marécal
- Centre National de Recherche Météorologique, UMR3589, Méteo-France-CNRS, Toulouse, France
| | - Olaf Morgenstern
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
| | - Luke D Oman
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Laura L Pan
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Carl Percival
- Department of Chemistry, University of Manchester, UK
| | - David Plummer
- Canadian Centre for Climate Modeling and Analysis, Environment Canada, Victoria, British Columbia, Canada
| | - Laura E Revell
- Bodeker Scientific, Alexandra, New Zealand
- ETH Zürich, Institute for Atmospheric and Climate Science, Zürich, Switzerland
| | - Eugene Rozanov
- ETH Zürich, Institute for Atmospheric and Climate Science, Zürich, Switzerland
- Physikalisch-Meteorologisches Observatorium Davos World Radiation Centre, Davos Dorf, Switzerland
| | - Alfonso Saiz-Lopez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
| | - Andrea Stenke
- ETH Zürich, Institute for Atmospheric and Climate Science, Zürich, Switzerland
| | - Kengo Sudo
- Nagoya University, Graduate School of Environmental Studies, Nagoya, Japan
- Japan Marine-Earth Science and Technology, Yokohama, Japan
| | - Simone Tilmes
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Kirk Ullmann
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - Rainer Volkamer
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, Colorado, USA
| | | | - Guang Zeng
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
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5
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Kühnreich B, Höh M, Wagner S, Ebert V. Direct single-mode fibre-coupled miniature White cell for laser absorption spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:023111. [PMID: 26931838 DOI: 10.1063/1.4941748] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present the design, setup, and characterization of a new lens-free fibre-coupled miniature White cell for extractive gas analysis using direct tunable diode laser absorption spectroscopy (dTDLAS). The construction of this cell is based on a modified White cell design and allows for an easy variation of the absorption length in the range from 29 cm to 146 cm. The design avoids parasitic absorption paths outside the cell by using direct, lensless fibre coupling and allows small physical cell dimensions and cell volumes. To characterize the cell performance, different H2O and CH4 concentration levels were measured using dTDLAS. Detection limits of 2.5 ppm ⋅ m for CH4 (at 1.65 μm) and 1.3 ppm ⋅ m for H2O (at 1.37 μm) were achieved. In addition, the gas exchange time and its flow-rate dependence were determined for both species and found to be less than 15 s for CH4 and up to a factor of thirteen longer for H2O.
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Affiliation(s)
- Benjamin Kühnreich
- High Temperature Process Diagnostics, Technische Universität Darmstadt, Darmstadt, Germany
| | - Matthias Höh
- Reactive Flows and Diagnostics, Technische Universität Darmstadt, Darmstadt, Germany
| | - Steven Wagner
- High Temperature Process Diagnostics, Technische Universität Darmstadt, Darmstadt, Germany
| | - Volker Ebert
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
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6
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Anderson DC, Nicely JM, Salawitch RJ, Canty TP, Dickerson RR, Hanisco TF, Wolfe GM, Apel EC, Atlas E, Bannan T, Bauguitte S, Blake NJ, Bresch JF, Campos TL, Carpenter LJ, Cohen MD, Evans M, Fernandez RP, Kahn BH, Kinnison DE, Hall SR, Harris NRP, Hornbrook RS, Lamarque JF, Le Breton M, Lee JD, Percival C, Pfister L, Pierce RB, Riemer DD, Saiz-Lopez A, Stunder BJB, Thompson AM, Ullmann K, Vaughan A, Weinheimer AJ. A pervasive role for biomass burning in tropical high ozone/low water structures. Nat Commun 2016; 7:10267. [PMID: 26758808 PMCID: PMC4735513 DOI: 10.1038/ncomms10267] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 11/23/2015] [Indexed: 11/09/2022] Open
Abstract
Air parcels with mixing ratios of high O3 and low H2O (HOLW) are common features in the tropical western Pacific (TWP) mid-troposphere (300-700 hPa). Here, using data collected during aircraft sampling of the TWP in winter 2014, we find strong, positive correlations of O3 with multiple biomass burning tracers in these HOLW structures. Ozone levels in these structures are about a factor of three larger than background. Models, satellite data and aircraft observations are used to show fires in tropical Africa and Southeast Asia are the dominant source of high O3 and that low H2O results from large-scale descent within the tropical troposphere. Previous explanations that attribute HOLW structures to transport from the stratosphere or mid-latitude troposphere are inconsistent with our observations. This study suggest a larger role for biomass burning in the radiative forcing of climate in the remote TWP than is commonly appreciated.
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Affiliation(s)
- Daniel C Anderson
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland 20742, USA
| | - Julie M Nicely
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - Ross J Salawitch
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland 20742, USA.,Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA.,Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland 20742, USA
| | - Timothy P Canty
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland 20742, USA
| | - Russell R Dickerson
- Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland 20742, USA
| | - Thomas F Hanisco
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - Glenn M Wolfe
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.,Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, Maryland 21250, USA
| | - Eric C Apel
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
| | - Elliot Atlas
- Department of Atmospheric Sciences, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida 33149, USA
| | - Thomas Bannan
- Centre for Atmospheric Science, School of Earth, Atmospheric, and Environmental Science, The University of Manchester, Manchester M13 9PL, UK
| | | | - Nicola J Blake
- Deparment of Chemistry, University of California, Irvine, California 92697, USA
| | - James F Bresch
- Mesoscale and Microscale Meteorology Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
| | - Teresa L Campos
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
| | - Lucy J Carpenter
- Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Mark D Cohen
- NOAA Air Resources Laboratory, College Park, Maryland 20740, USA
| | - Mathew Evans
- Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, UK.,National Centre for Atmospheric Science, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Rafael P Fernandez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid 28006, Spain.,Department of Natural Science, National Research Council (CONICET), FCEN-UNCuyo, Mendoza 5501, Argentina
| | - Brian H Kahn
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
| | - Douglas E Kinnison
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
| | - Samuel R Hall
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
| | - Neil R P Harris
- Department of Chemistry, Cambridge University, Cambridge CB2 1EW, UK
| | - Rebecca S Hornbrook
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
| | - Jean-Francois Lamarque
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA.,Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
| | - Michael Le Breton
- Centre for Atmospheric Science, School of Earth, Atmospheric, and Environmental Science, The University of Manchester, Manchester M13 9PL, UK
| | - James D Lee
- National Centre for Atmospheric Science, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Carl Percival
- Centre for Atmospheric Science, School of Earth, Atmospheric, and Environmental Science, The University of Manchester, Manchester M13 9PL, UK
| | - Leonhard Pfister
- Earth Sciences Division, NASA Ames Research Center, Moffett Field, California 94035, USA
| | - R Bradley Pierce
- NOAA/NESDIS Center for Satellite Applications and Research, Madison, Wisconsin 53706, USA
| | - Daniel D Riemer
- Department of Atmospheric Sciences, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida 33149, USA
| | - Alfonso Saiz-Lopez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid 28006, Spain
| | | | - Anne M Thompson
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - Kirk Ullmann
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
| | - Adam Vaughan
- National Centre for Atmospheric Science, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Andrew J Weinheimer
- Atmospheric Chemistry Observation and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, USA
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7
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Active and widespread halogen chemistry in the tropical and subtropical free troposphere. Proc Natl Acad Sci U S A 2015; 112:9281-6. [PMID: 26124148 DOI: 10.1073/pnas.1505142112] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Halogens in the troposphere are increasingly recognized as playing an important role for atmospheric chemistry, and possibly climate. Bromine and iodine react catalytically to destroy ozone (O3), oxidize mercury, and modify oxidative capacity that is relevant for the lifetime of greenhouse gases. Most of the tropospheric O3 and methane (CH4) loss occurs at tropical latitudes. Here we report simultaneous measurements of vertical profiles of bromine oxide (BrO) and iodine oxide (IO) in the tropical and subtropical free troposphere (10 °N to 40 °S), and show that these halogens are responsible for 34% of the column-integrated loss of tropospheric O3. The observed BrO concentrations increase strongly with altitude (∼ 3.4 pptv at 13.5 km), and are 2-4 times higher than predicted in the tropical free troposphere. BrO resembles model predictions more closely in stratospheric air. The largest model low bias is observed in the lower tropical transition layer (TTL) over the tropical eastern Pacific Ocean, and may reflect a missing inorganic bromine source supplying an additional 2.5-6.4 pptv total inorganic bromine (Bry), or model overestimated Bry wet scavenging. Our results highlight the importance of heterogeneous chemistry on ice clouds, and imply an additional Bry source from the debromination of sea salt residue in the lower TTL. The observed levels of bromine oxidize mercury up to 3.5 times faster than models predict, possibly increasing mercury deposition to the ocean. The halogen-catalyzed loss of tropospheric O3 needs to be considered when estimating past and future ozone radiative effects.
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Sun K, Tao L, Miller DJ, Khan MA, Zondlo MA. On-road ammonia emissions characterized by mobile, open-path measurements. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3943-50. [PMID: 24517544 DOI: 10.1021/es4047704] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Ammonia (NH3) is a key precursor species to atmospheric fine particulate matter with strong implications for regional air quality and global climate change. NH3 from vehicles accounts for a significant fraction of total emissions of NH3 in urban areas. A mobile platform is developed to measure NH3, CO, and CO2 from the top of a passenger car. The mobile platform conducted 87 h of on-road measurements, covering 4500 km in New Jersey and California. The average on-road emission factor (EF) in CA is 0.49 ± 0.06 g NH3 per kg fuel and agrees with previous studies in CA (0.3-0.8 g/kg). The mean on-road NH3:CO emission ratio is 0.029 ± 0.005, and there is no systematic difference between NJ and CA. On-road NH3 EFs increase with road gradient by an enhancement of 53 mg/kg fuel per percentage of gradient. On-road NH3 EFs show higher values in both stop-and-go driving conditions and freeway speeds with a minimum near 70 km/h. Consistent with prior studies, the on-road emission ratios suggest a highly skewed distribution of NH3 emitters. Comparisons with existing NJ and CA on-road emission inventories indicate that there may be an underestimation of on-road NH3 emissions in both NJ and CA. We demonstrate that mobile, open-path measurements provide a unique tool to help quantitatively understand the on-road NH3 emissions in urban and suburban settings.
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Affiliation(s)
- Kang Sun
- Department of Civil and Environmental Engineering, Princeton University , Princeton, New Jersey 08544, United States
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Nikodem M, Wysocki G. Measuring optically thick molecular samples using chirped laser dispersion spectroscopy. OPTICS LETTERS 2013; 38:3834-3837. [PMID: 24081065 DOI: 10.1364/ol.38.003834] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this Letter, a dispersion-based gas sensing method applied to detection of optically thick samples is presented. We show that chirped laser dispersion spectroscopy (CLaDS) technique provides perfectly linear signal response over a wide range of target analyte concentrations. Using the most convenient chirp-modulated CLaDS detection scheme, it enables spectroscopic measurements in a line-locked mode from the minimum detection limit up to >99% peak molecular absorption.
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Sargent MR, Sayres DS, Smith JB, Witinski M, Allen NT, Demusz JN, Rivero M, Tuozzolo C, Anderson JG. A new direct absorption tunable diode laser spectrometer for high precision measurement of water vapor in the upper troposphere and lower stratosphere. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:074102. [PMID: 23902086 DOI: 10.1063/1.4815828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present a new instrument for the measurement of water vapor in the upper troposphere and lower stratosphere (UT∕LS), the Harvard Herriott Hygrometer (HHH). HHH employs a tunable diode near-IR laser to measure water vapor via direct absorption in a Herriott cell. The direct absorption technique provides a direct link between the depth of the observed absorption line and the measured water vapor concentration, which is calculated based on spectroscopic parameters in the HITRAN database. While several other tunable diode laser (TDL) instruments have been used to measure water vapor in the UT∕LS, HHH is set apart by its use of an optical cell an order of magnitude smaller than those of other direct absorption TDLs in operation, allowing for a more compact, lightweight instrument. HHH is also unique in its integration into a common duct with the Harvard Lyman-α hygrometer, an independent photo-fragment fluorescence instrument which has been thoroughly validated over 19 years of flight measurements. The instrument was flown for the first time in the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) on NASA's WB-57 aircraft in spring, 2011, during which it demonstrated in-flight precision of 0.1 ppmv (1 s) with 1-sigma uncertainty of 5% ± 0.7 ppmv. Since the campaign, changes to the instrument have lead to improved accuracy of 5% ± 0.2 ppmv as demonstrated in the laboratory. During MACPEX, HHH successfully measured water vapor at concentrations from 3.5 to 600 ppmv in the upper troposphere and lower stratosphere. HHH and Lyman-α, measuring independently but under the same sampling conditions, agreed on average to within 1% at water vapor mixing ratios above 20 ppmv and to within 0.3 ppmv at lower mixing ratios. HHH also agreed with a number of other in situ water vapor instruments on the WB-57 to within their stated uncertainties, and to within 0.7 ppmv at low water. This agreement constitutes a significant improvement over past in situ comparisons, in which differences of 1.5-2 ppmv were routinely observed, and demonstrates that the accuracy of HHH is consistent with other instruments which use a range of detection methods and sampling techniques.
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Affiliation(s)
- M R Sargent
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
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Cziczo DJ, Froyd KD, Hoose C, Jensen EJ, Diao M, Zondlo MA, Smith JB, Twohy CH, Murphy DM. Clarifying the Dominant Sources and Mechanisms of Cirrus Cloud Formation. Science 2013; 340:1320-4. [DOI: 10.1126/science.1234145] [Citation(s) in RCA: 371] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Tao L, Sun K, Khan MA, Miller DJ, Zondlo MA. Compact and portable open-path sensor for simultaneous measurements of atmospheric N2O and CO using a quantum cascade laser. OPTICS EXPRESS 2012; 20:28106-28118. [PMID: 23263046 DOI: 10.1364/oe.20.028106] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A compact and portable open-path sensor for simultaneous detection of atmospheric N(2)O and CO has been developed with a 4.5 μm quantum cascade laser (QCL). An in-line acetylene (C(2)H(2)) gas reference cell allows for continuous monitoring of the sensor drift and calibration in rapidly changing field environments and thereby allows for open-path detection at high precision and stability. Wavelength modulation spectroscopy (WMS) is used to detect simultaneously both the second and fourth harmonic absorption spectra with an optimized dual modulation amplitude scheme. Multi-harmonic spectra containing atmospheric N(2)O, CO, and the reference C(2)H(2) signals are fit in real-time (10 Hz) by combining a software-based lock-in amplifier with a computationally fast numerical model for WMS. The sensor consumes ~50 W of power and has a mass of ~15 kg. Precision of 0.15 ppbv N(2)O and 0.36 ppbv CO at 10 Hz under laboratory conditions was demonstrated. The sensor has been deployed for extended periods in the field. Simultaneous N(2)O and CO measurements distinguished between natural and fossil fuel combustion sources of N(2)O, an important greenhouse gas with poorly quantified emissions in space and time.
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Affiliation(s)
- Lei Tao
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544, USA
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Homeyer CR, Bowman KP, Pan LL, Zondlo MA, Bresch JF. Convective injection into stratospheric intrusions. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd016724] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wofsy SC. HIAPER Pole-to-Pole Observations (HIPPO): fine-grained, global-scale measurements of climatically important atmospheric gases and aerosols. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2011; 369:2073-86. [PMID: 21502177 DOI: 10.1098/rsta.2010.0313] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The HIAPER Pole-to-Pole Observations (HIPPO) programme has completed three of five planned aircraft transects spanning the Pacific from 85 ° N to 67 ° S, with vertical profiles every approximately 2.2 ° of latitude. Measurements include greenhouse gases, long-lived tracers, reactive species, O(2)/N(2) ratio, black carbon (BC), aerosols and CO(2) isotopes. Our goals are to address the problem of determining surface emissions, transport strength and patterns, and removal rates of atmospheric trace gases and aerosols at global scales and to provide strong tests of satellite data and global models. HIPPO data show dense pollution and BC at high altitudes over the Arctic, imprints of large N(2)O sources from tropical lands and convective storms, sources of pollution and biogenic CH(4) in the Arctic, and summertime uptake of CO(2) and sources for O(2) at high southern latitudes. Global chemical signatures of atmospheric transport are imaged, showing remarkably sharp horizontal gradients at air mass boundaries, weak vertical gradients and inverted profiles (maxima aloft) in both hemispheres. These features challenge satellite algorithms, global models and inversion analyses to derive surface fluxes. HIPPO data can play a crucial role in identifying and resolving questions of global sources, sinks and transport of atmospheric gases and aerosols.
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Affiliation(s)
- S C Wofsy
- Harvard University, Cambridge, MA, USA.
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Tilmes S, Pan LL, Hoor P, Atlas E, Avery MA, Campos T, Christensen LE, Diskin GS, Gao RS, Herman RL, Hintsa EJ, Loewenstein M, Lopez J, Paige ME, Pittman JV, Podolske JR, Proffitt MR, Sachse GW, Schiller C, Schlager H, Smith J, Spelten N, Webster C, Weinheimer A, Zondlo MA. An aircraft-based upper troposphere lower stratosphere O3, CO, and H2O climatology for the Northern Hemisphere. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd012731] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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