Atmospheric Acetaldehyde: Importance of Air-Sea Exchange and a Missing Source in the Remote Troposphere
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.
Additional Information
© 2019 American Geophysical Union. Accepted 18 APR 2019; Accepted article online 29 APR 2019; Published online 28 MAY 2019. The Atmospheric Tomography Mission (ATom) is funded by the Earth Science Project Office at NASA (NNX15AJ23G, NNX15AH33A, NNX15AG70A, NNX15AG61A, NNX15AG71A, NNH15AB12I, NNX15AJ91A). ATom data are publicly available at https://espo.nasa.gov/atom as well as Wofsy et al. (2018). S.‐Y. W. is supported by the NCAR Advanced Study Program (ASP) Postdoctoral Fellowship. We thank NASA ESPO, the NASA DC‐8 crew, and the ATom Science Team for their exceptional professionalism in support of this mission. Alex Thames, David Miller, and William H. Brune (Pennsylvania State University) are acknowledged for the HOx measurements. Charles Brock, Christina Williamson, Agnieszka Kupc, and Karl Froyd (Earth System Research Laboratory/Chemical Science Division/National Ocean and Atmospheric Administration) are acknowledged for the condensation and optically based particle counters. Kathryn McKain and Colm Sweeney (Earth System Research Laboratory/Global Monitoring Division/National Ocean and Atmospheric Administration) are acknowledged for the methane and carbon monoxide measurements. Glenn S. Diskin and Joshua P. DiGangi are acknowledged for the Diode Laser Hygrometer measurements of water vapor. The CESM project is supported primarily by the National Science Foundation (NSF). This material is based upon work supported by the National Center for Atmospheric Research, which is a major facility sponsored by the NSF under Cooperative Agreement 1852977. Computing and data storage resources, including the Cheyenne supercomputer (doi:10.5065/D6RX99HX), were provided by the Computational and Information Systems Laboratory (CISL) at NCAR. We thank the Editor and two anonymous reviewers for their constructive comments and feedback, which helped us to improve the manuscript. The authors declare that they have no conflict of interest.Attached Files
Published - Wang_et_al-2019-Geophysical_Research_Letters.pdf
Accepted Version - nihms-1536059.pdf
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Additional details
- PMCID
- PMC7325730
- Eprint ID
- 95069
- Resolver ID
- CaltechAUTHORS:20190429-101828226
- NNX15AJ23G
- NASA
- NNX15AH33A
- NASA
- NNX15AG70A
- NASA
- NNX15AG61A
- NASA
- NNX15AG71A
- NASA
- NNH15AB12I
- NASA
- NNX15AJ91A
- NASA
- National Center for Atmospheric Research (NCAR)
- AGS-1852977
- NSF
- Created
-
2019-04-29Created from EPrint's datestamp field
- Updated
-
2022-02-15Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences