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Zhu Q, Wang W, Shan C, Xie Y, Zeng X, Wu P, Liang B, Liu C. Effects of biomass burning on CO, HCN, C 2H 6, C 2H 2 and H 2CO during long-term FTIR measurements in Hefei, China. OPTICS EXPRESS 2024; 32:8343-8363. [PMID: 38439492 DOI: 10.1364/oe.516258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 02/08/2024] [Indexed: 03/06/2024]
Abstract
High-resolution solar absorption spectra were continuously collected by a ground-based Fourier transform infrared (FTIR) spectrometer to retrieve the total column of carbon monoxide (CO), hydrogen cyanide (HCN), ethane (C2H6), acetylene (C2H2), and formaldehyde (H2CO). The time series and variation characteristics of these gases were analyzed. The biomass combustion process is identified by using the correlations between the monthly mean deviations of HCN, C2H6, C2H2 and H2CO versus CO and satellite fire point data. The months with high correlation coefficients (R > 0.8) and peaks of fire point number are considered to be with biomass combustion occurrence. The emissions of HCN, C2H6, C2H2 and H2CO in Anhui were estimated using the enhancement ratios of gases to CO in these months when biomass combustion was the main driving factor of gas concentration change. The study proved the ability of FTIR system in inferring the period during biomass combustion and estimating emissions of the trace gases concerning biomass combustion.
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Peng Y, Yuan B, Yang S, Wang S, Yang X, Wang W, Li J, Song X, Wu C, Qi J, Zheng E, Ye C, Huang S, Hu W, Song W, Wang X, Wang B, Shao M. Photolysis frequency of nitrophenols derived from ambient measurements. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161810. [PMID: 36702278 DOI: 10.1016/j.scitotenv.2023.161810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 01/02/2023] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
Nitrophenols, a class of important intermediate products from the oxidation of aromatics, can participate in photochemistry and influence the atmospheric oxidative capacity. However, the reported photolysis frequencies of nitrophenols show considerable discrepancies. Here, measurements of nitrophenol, and methyl nitrophenol using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) at both urban and regional sites in southern China are used to constrain photolysis frequencies of nitrophenols. Considerable concentrations with a campaign average of 58 ± 32 ppt for nitrophenol and 97 ± 59 ppt for methyl nitrophenol were observed at the regional site. Based on the in-situ measurement dataset, a steady-state calculation was performed along with a zero-dimensional box model to analyze the budgets of nitrophenols. The result indicates that both primary emission and photolysis have significant impacts on nitrophenols. Primary emission contributes up to 88 % of the total nitrophenols production while photolysis accounts for up to 98 % of the total removal rate. The dominant sink of nitrophenols is photolysis with a rate of about 3.5 % ± 1.3 % of jNO2 for nitrophenol and 2.4 % ± 1.0 % of jNO2 for methyl nitrophenol. The results of this study suggest that using advanced mass spectrometry to accurately measure ambient nitrophenols, supplemented by an observation-based box model for budget analysis, provides an important indication for determining photolysis rate constants of nitrophenols.
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Affiliation(s)
- Yuwen Peng
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Bin Yuan
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China.
| | - Suxia Yang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Sihang Wang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Xiaoyun Yang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Wenjie Wang
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz 55128, Germany
| | - Jin Li
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Xin Song
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Caihong Wu
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Jipeng Qi
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - E Zheng
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Chenshuo Ye
- Guangdong Provincial Academy of Environmental Science, Guangzhou 510045, China
| | - Shan Huang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
| | - Weiwei Hu
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Wei Song
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Baolin Wang
- School of Environmental Science and Engineering, Qilu University of Technology, Jinan 250353, China
| | - Min Shao
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
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Liu T, Lin Y, Chen J, Chen G, Yang C, Xu L, Li M, Fan X, Zhang F, Hong Y. Pollution mechanisms and photochemical effects of atmospheric HCHO in a coastal city of southeast China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 859:160210. [PMID: 36395845 DOI: 10.1016/j.scitotenv.2022.160210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 11/10/2022] [Accepted: 11/12/2022] [Indexed: 06/16/2023]
Abstract
Formaldehyde (HCHO) is a vital reactive carbonyl compound, which plays an important role in the photochemical process and atmospheric oxidation capacity. However, the current studies on the quantification of HCHO impacts on atmospheric photochemistry in southeast coastal areas of China with an obvious upward trend of ozone remain scarce and unclear, thus limiting the full understanding of formation mechanism and control strategy of photochemical pollution. Here, systematic field campaigns were conducted at a typical coastal urban site with good air quality to reveal HCHO mechanism and effects on O3 pollution mechanism during spring and autumn, when photochemical pollution events still frequently appeared. Positive Matrix Factorization model results showed that secondary photochemical formation made the largest contributions to HCHO (69 %) in this study. Based on the photochemical model, the HCHO loss rates in autumn were significantly higher than those in spring (P < 0.05), indicating that strong photochemical conditions constrain high HCHO levels in certain situations. HCHO mechanism increased the ROx concentrations by 36 %, and increased net O3 production rates by 31 %, manifesting that the reduction of HCHO and its precursors' emissions would effectively mitigate O3 pollution. Therefore, the pollution characteristics and photochemical effects of HCHO provided significant guidance for future photochemical pollution control in relatively clean areas.
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Affiliation(s)
- Taotao Liu
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yiling Lin
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Jinsheng Chen
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
| | - Gaojie Chen
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; University of Chinese Academy of Sciences, Beijing, China
| | - Chen Yang
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; University of Chinese Academy of Sciences, Beijing, China
| | - Lingling Xu
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Mengren Li
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Xiaolong Fan
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Fuwang Zhang
- Environmental Monitoring Center of Fujian, Fuzhou, China
| | - Youwei Hong
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
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Moch JM, Dovrou E, Mickley LJ, Keutsch FN, Liu Z, Wang Y, Dombek TL, Kuwata M, Budisulistiorini SH, Yang L, Decesari S, Paglione M, Alexander B, Shao J, Munger JW, Jacob DJ. Global Importance of Hydroxymethanesulfonate in Ambient Particulate Matter: Implications for Air Quality. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2020; 125:e2020JD032706. [PMID: 33282612 PMCID: PMC7685164 DOI: 10.1029/2020jd032706] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 07/18/2020] [Accepted: 07/28/2020] [Indexed: 05/14/2023]
Abstract
Sulfur compounds are an important constituent of particulate matter, with impacts on climate and public health. While most sulfur observed in particulate matter has been assumed to be sulfate, laboratory experiments reveal that hydroxymethanesulfonate (HMS), an adduct formed by aqueous phase chemical reaction of dissolved HCHO and SO2, may be easily misinterpreted in measurements as sulfate. Here we present observational and modeling evidence for a ubiquitous global presence of HMS. We find that filter samples collected in Shijiazhuang, China, and examined with ion chromatography within 9 days show as much as 7.6 μg m-3 of HMS, while samples from Singapore examined 9-18 months after collection reveal ~0.6 μg m-3 of HMS. The Shijiazhuang samples show only minor traces of HMS 4 months later, suggesting that HMS had decomposed over time during sample storage. In contrast, the Singapore samples do not clearly show a decline in HMS concentration over 2 months of monitoring. Measurements from over 150 sites, primarily derived from the IMPROVE network across the United States, suggest the ubiquitous presence of HMS in at least trace amounts as much as 60 days after collection. The degree of possible HMS decomposition in the IMPROVE observations is unknown. Using the GEOS-Chem chemical transport model, we estimate that HMS may account for 10% of global particulate sulfur in continental surface air and over 25% in many polluted regions. Our results suggest that reducing emissions of HCHO and other volatile organic compounds may have a co-benefit of decreasing particulate sulfur.
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Affiliation(s)
- Jonathan M. Moch
- Department of Earth and Planetary SciencesHarvard UniversityCambridgeMAUSA
| | - Eleni Dovrou
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
| | - Loretta J. Mickley
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
| | - Frank N. Keutsch
- Department of Earth and Planetary SciencesHarvard UniversityCambridgeMAUSA
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
- Department of Chemistry and Chemical BiologyHarvard UniversityCambridgeMAUSA
| | - Zirui Liu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina
| | - Yuesi Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina
| | - Tracy L. Dombek
- Analytical Sciences Division, RTI International, Research Triangle ParkDurhamNCUSA
| | - Mikinori Kuwata
- Asian School of the Environment and Earth Observatory of SingaporeNanyang Technological UniversitySingapore
- Now in the Department of Atmospheric and Oceanic Sciences, School of Physics, and BIC‐ESATPeking UniversityBeijingChina
| | - Sri Hapsari Budisulistiorini
- Asian School of the Environment and Earth Observatory of SingaporeNanyang Technological UniversitySingapore
- Now in Wolfson Atmospheric Chemistry Laboratories, Department of ChemistryUniversity of YorkYorkUK
| | - Liudongqing Yang
- Asian School of the Environment and Earth Observatory of SingaporeNanyang Technological UniversitySingapore
| | - Stefano Decesari
- Italian National Research Council ‐ Institute of Atmospheric Sciences and Climate (CNR‐ISAC)BolognaItaly
| | - Marco Paglione
- Italian National Research Council ‐ Institute of Atmospheric Sciences and Climate (CNR‐ISAC)BolognaItaly
| | - Becky Alexander
- Department of Atmospheric SciencesUniversity of WashingtonWAUSA
| | - Jingyuan Shao
- Department of Atmospheric SciencesUniversity of WashingtonWAUSA
- College of Flying TechnologyCivil Aviation University of ChinaTianjinChina
| | - J. William Munger
- Department of Earth and Planetary SciencesHarvard UniversityCambridgeMAUSA
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
| | - Daniel J. Jacob
- Department of Earth and Planetary SciencesHarvard UniversityCambridgeMAUSA
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
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5
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Wang S, Apel EC, Hornbrook RS, Hills A, Emmons LK, Tilmes S, Lamarque JF, Jimenez JL, Campuzano-Jost P, Nault BA, Crounse JD, Wennberg PO, Ryerson TB, Thompson CR, Peischl J, Moore F, Nance D, Hall B, Elkins J, Tanner D, Gregory Huey L, Hall SR, Ullmann K, Orlando JJ, Tyndall GS, Flocke FM, Ray E, Hanisco TF, Wolfe GM, St.Clair J, Commane R, Daube B, Barletta B, Blake DR, Weinzierl B, Dollner M, Conley A, Vitt F, Wofsy SC, Riemer DD. Atmospheric Acetaldehyde: Importance of Air-Sea Exchange and a Missing Source in the Remote Troposphere. GEOPHYSICAL RESEARCH LETTERS 2019; 46:5601-5613. [PMID: 32606484 PMCID: PMC7325730 DOI: 10.1029/2019gl082034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/18/2019] [Indexed: 06/02/2023]
Abstract
We report airborne measurements of acetaldehyde (CH3CHO) during the first and second deployments of the National Aeronautics and Space Administration (NASA) Atmospheric Tomography Mission (ATom). The budget of CH3CHO is examined using the Community Atmospheric Model with chemistry (CAM-chem), with a newly-developed online air-sea exchange module. The upper limit of the global ocean net emission of CH3CHO is estimated to be 34 Tg a-1 (42 Tg a-1 if considering bubble-mediated transfer), and the ocean impacts on tropospheric CH3CHO are mostly confined to the marine boundary layer. Our analysis suggests that there is an unaccounted CH3CHO source in the remote troposphere and that organic aerosols can only provide a fraction of this missing source. We propose that peroxyacetic acid (PAA) is an ideal indicator of the rapid CH3CHO production in the remote troposphere. The higher-than-expected CH3CHO measurements represent a missing sink of hydroxyl radicals (and halogen radical) in current chemistry-climate models.
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Affiliation(s)
- Siyuan Wang
- Advanced Study Program (ASP), National Center for Atmospheric Research, Boulder CO, 80301
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Eric C. Apel
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Rebecca S. Hornbrook
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Alan Hills
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Louisa K. Emmons
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Simone Tilmes
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
- Climate and Global Dynamics, National Center for Atmospheric Research, Boulder CO, 80301
| | - Jean-François Lamarque
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
- Climate and Global Dynamics, National Center for Atmospheric Research, Boulder CO, 80301
| | - Jose L. Jimenez
- Department of Chemistry and Biochemistry, University of Colorado Boulder, CO 80309
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder, CO 80309
| | - Pedro Campuzano-Jost
- Department of Chemistry and Biochemistry, University of Colorado Boulder, CO 80309
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder, CO 80309
| | - Benjamin A. Nault
- Department of Chemistry and Biochemistry, University of Colorado Boulder, CO 80309
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder, CO 80309
| | - John D. Crounse
- Division of Engineering and Applied Science, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - Paul O. Wennberg
- Division of Engineering and Applied Science, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - Thomas B. Ryerson
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305
| | - Chelsea R. Thompson
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder, CO 80309
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305
| | - Jeff Peischl
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder, CO 80309
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305
| | - Fred Moore
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305
| | - David Nance
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305
| | - Brad Hall
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305
| | - James Elkins
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305
| | - David Tanner
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - L. Gregory Huey
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Samuel R. Hall
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Kirk Ullmann
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - John J. Orlando
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Geoff S. Tyndall
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Frank M. Flocke
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Eric Ray
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305
| | - Thomas F. Hanisco
- Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD 20771
| | - Glenn M. Wolfe
- Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD 20771
- Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD 21228
| | - Jason St.Clair
- Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD 20771
- Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD 21228
| | - Róisín Commane
- Harvard School of Engineering and Applied Sciences, Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138
- Department of Earth & Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964
| | - Bruce Daube
- Harvard School of Engineering and Applied Sciences, Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138
| | - Barbara Barletta
- Department of Chemistry, University of California Irvine, Irvine; CA 92697
| | - Donald R. Blake
- Department of Chemistry, University of California Irvine, Irvine; CA 92697
| | - Bernadett Weinzierl
- Faculty of Physics, Aerosol Physics and Environmental Physics, University of Vienna, Wien, Austria
| | - Maximilian Dollner
- Faculty of Physics, Aerosol Physics and Environmental Physics, University of Vienna, Wien, Austria
| | - Andrew Conley
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Francis Vitt
- Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, 80301
| | - Steven C. Wofsy
- Harvard School of Engineering and Applied Sciences, Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138
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Mapping hydroxyl variability throughout the global remote troposphere via synthesis of airborne and satellite formaldehyde observations. Proc Natl Acad Sci U S A 2019; 116:11171-11180. [PMID: 31110019 DOI: 10.1073/pnas.1821661116] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The hydroxyl radical (OH) fuels tropospheric ozone production and governs the lifetime of methane and many other gases. Existing methods to quantify global OH are limited to annual and global-to-hemispheric averages. Finer resolution is essential for isolating model deficiencies and building process-level understanding. In situ observations from the Atmospheric Tomography (ATom) mission demonstrate that remote tropospheric OH is tightly coupled to the production and loss of formaldehyde (HCHO), a major hydrocarbon oxidation product. Synthesis of this relationship with satellite-based HCHO retrievals and model-derived HCHO loss frequencies yields a map of total-column OH abundance throughout the remote troposphere (up to 70% of tropospheric mass) over the first two ATom missions (August 2016 and February 2017). This dataset offers unique insights on near-global oxidizing capacity. OH exhibits significant seasonality within individual hemispheres, but the domain mean concentration is nearly identical for both seasons (1.03 ± 0.25 × 106 cm-3), and the biseasonal average North/South Hemisphere ratio is 0.89 ± 0.06, consistent with a balance of OH sources and sinks across the remote troposphere. Regional phenomena are also highlighted, such as a 10-fold OH depression in the Tropical West Pacific and enhancements in the East Pacific and South Atlantic. This method is complementary to budget-based global OH constraints and can help elucidate the spatial and temporal variability of OH production and methane loss.
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