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Measurements of atmospheric HDO/H₂O in southern California from CLARS-FTS

Zeng, Zhao-Cheng and Addington, Olivia and Pongetti, Thomas J. and Herman, Robert L. and Sung, Keeyoon and Newman, Sally and Schneider, Andreas and Borsdorff, Tobias and Yung, Yuk L. and Sander, Stanley P. (2021) Measurements of atmospheric HDO/H₂O in southern California from CLARS-FTS. . (Unpublished)

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Atmospheric isotopologues of water vapor (e.g., HDO) are important tracers for understanding Earth’s hydrological cycles. Most remote sensing measurements of these isotopologues, however, are column averaged values and sparse in space and time. Measurements targeting the planetary boundary layer (PBL) are much rarer. In this study, we retrieved HDO and H from CLARS-FTS observations (2011-2019). The isotopological abundance δD, which represents the relative difference of the HDO/H₂O ratio to a standard abundance ratio, is also calculated. The averaged δD retrievals are (−156.1±60.0)‰ with an uncertainty of (6.1±10.2)‰ for LA Basin Survey m and (−344.7±95.0)‰ with an uncertainty of (42.4±31.6)‰ for Spectralon Viewing Observation mode. In LA, the δD shows a seasonal cycle that is primarily driven by the change of atmospheric humidity. The temporal variabilities in δD data between CLARS-FTS and a collocated Total Carbon Column Observing Network (TCCON) observatory are highly correlated. The difference between CLARS and TCCON δD retrievals can primarily be attributed to the difference in their observation geometries. We conclude that the HDO and δD measurements from CLARS-FTS provide high spatial and temporal resolution datasets for further study of hydrological processes in the LA megacity.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
https://megacities.jpl.nasa.govRelated ItemCLARS-FTS data ItemTROPOMI HDO data set data archive
Zeng, Zhao-Cheng0000-0002-0008-6508
Pongetti, Thomas J.0000-0001-9465-0853
Herman, Robert L.0000-0001-7063-6424
Sung, Keeyoon0000-0002-8030-7410
Newman, Sally0000-0003-0710-995X
Borsdorff, Tobias0000-0002-4421-0187
Yung, Yuk L.0000-0002-4263-2562
Sander, Stanley P.0000-0003-1424-3620
Alternate Title:Measurements of atmospheric HDO/H2O in southern California from CLARS-FTS
Additional Information:License: Non-exclusive. Published Online: Sat, 27 Feb 2021. We would like to thank Geoffrey Toon (JPL) for proofreading and suggestions on the first draft of this manuscript, and Paul Wennberg (Caltech) and Coleen Roehl (Caltech) for providing the TCCON data. OA would like to thank the National Science Foundation COSMOS Scholarship, the Maximizing Student Potential in STEM program at the Jet Propulsion Laboratory, and Occidental College Undergraduate Research Center for helping to fund the summer experience. The CLARS project receives support from the California Air Resources Board. However, the results presented in this study do not necessarily present the views of the funding agency. Part of the CLARS-FTS data are available from the NASA Megacities Project at The TROPOMI HDO data set from this study is available for download at (last access: 12 December 2020). TCCON data are available from the TCCON Data Archive: Part of the research described in this article was performed at the Jet Propulsion Laboratory, California Institute of Technology and NASA under contracts with the National Aeronautics and Space Administration.
Funding AgencyGrant Number
Occidental CollegeUNSPECIFIED
California Air Resources BoardUNSPECIFIED
Record Number:CaltechAUTHORS:20210301-145107206
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108255
Deposited By: Tony Diaz
Deposited On:02 Mar 2021 01:20
Last Modified:02 Mar 2021 01:20

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