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Ganguly A, Padhya V, Oza H, Strauch G, Deshpande RD. New insights into diffusive kinetic fractionation during liquid condensation under supersaturated environment: an alternative approach for isotope tagging of ground-level water vapour. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2023; 59:1-26. [PMID: 36562740 DOI: 10.1080/10256016.2022.2153126] [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: 05/20/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Stable water isotopes in ground-level vapour are key to estimating water exchange between geospheres. Their sampling, however, is limited to laser-absorption spectrometers and satellite observations, having inherent shortcomings. This study investigates diffusive kinetic fractionation during liquid condensation under supersaturated environment, providing a cost-effective, reliable way of sampling ground-level vapour isotopes (18O, 2H). Experiments were undertaken at three locations in India with 'liquid' samples collected from condensation of ambient air at 0°C. Simultaneously, pristine 'vapour' was sampled via cryogenic-trapping using liquid nitrogen-alcohol slush at -78°C. The 'liquid' condensed under supersaturation was progressively more depleted in 18O, and less enriched in 2H than expected under equilibrium fractionation, with an increasing degree of supersaturation expressed as saturation index (Si). This study revealed: (1) Si, molecular density, Rh, T together control the extent of isotopic kinetic fractionation. (2) The presence of diffusive concentration gradient inhibits the flow of heavier isotopes during liquid condensation. (3) The stochastic nature of the process cannot be explained using a physics-based model alone. The artificial neural network model is hence deployed to sample δ18O (δ 2H) within -0.24 ± 1.79‰ (0.53 ± 11.23 ‰) of true value. (4) The approach can be extended to ground-validate isotope-enabled general circulation models and satellite observations.
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Affiliation(s)
- Akash Ganguly
- Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad, India
- Indian Institute of Technology Gandhinagar, Gandhinagar, India
| | - Virendra Padhya
- Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad, India
| | - Harsh Oza
- Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad, India
| | - Gerhard Strauch
- Department of Hydrogeology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
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Galewsky J, Steen-Larsen HC, Field RD, Worden J, Risi C, Schneider M. Stable isotopes in atmospheric water vapor and applications to the hydrologic cycle. REVIEWS OF GEOPHYSICS (WASHINGTON, D.C. : 1985) 2016; 54:809-865. [PMID: 32661517 PMCID: PMC7357203 DOI: 10.1002/2015rg000512] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The measurement and simulation of water vapor isotopic composition has matured rapidly over the last decade, with long-term datasets and comprehensive modeling capabilities now available. Theories for water vapor isotopic composition have been developed by extending the theories that have been used for the isotopic composition of precipitation to include a more nuanced understanding of evaporation, large-scale mixing, deep convection, and kinetic fractionation. The technologies for in-situ and remote sensing measurements of water vapor isotopic composition have developed especially rapidly over the last decade, with discrete water vapor sampling methods, based on mass spectroscopy, giving way to laser spectroscopic methods and satellite- and ground-based infrared absorption techniques. The simulation of water vapor isotopic composition has evolved from General Circulation Model (GCM) methods for simulating precipitation isotopic composition to sophisticated isotope-enabled microphysics schemes using higher-order moments for water- and ice-size distributions. The incorporation of isotopes into GCMs has enabled more detailed diagnostics of the water cycle and has led to improvements in its simulation. The combination of improved measurement and modeling of water vapor isotopic composition opens the door to new advances in our understanding of the atmospheric water cycle, in processes ranging from the marine boundary layer, through deep convection and tropospheric mixing, and into the water cycle of the stratosphere. Finally, studies of the processes governing modern water vapor isotopic composition provide an improved framework for the interpretation of paleoclimate proxy records of the hydrological cycle.
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Affiliation(s)
- Joseph Galewsky
- Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico, USA
| | | | - Robert D Field
- NASA Goddard Institute for Space Studies, New York, New York, USA
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York, USA
| | - John Worden
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Camille Risi
- Laboratoire de Meteorologie Dynamique, Institut Pierre Simon Laplace, Centre National de la Recherche Scientifique, Paris, France
| | - Matthias Schneider
- Institute for Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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Buenning NH, Stott L, Yoshimura K, Berkelhammer M. The cause of the seasonal variation in the oxygen isotopic composition of precipitation along the western U.S. coast. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd018050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Risi C, Noone D, Worden J, Frankenberg C, Stiller G, Kiefer M, Funke B, Walker K, Bernath P, Schneider M, Wunch D, Sherlock V, Deutscher N, Griffith D, Wennberg PO, Strong K, Smale D, Mahieu E, Barthlott S, Hase F, García O, Notholt J, Warneke T, Toon G, Sayres D, Bony S, Lee J, Brown D, Uemura R, Sturm C. Process-evaluation of tropospheric humidity simulated by general circulation models using water vapor isotopologues: 1. Comparison between models and observations. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016621] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Risi C, Noone D, Worden J, Frankenberg C, Stiller G, Kiefer M, Funke B, Walker K, Bernath P, Schneider M, Bony S, Lee J, Brown D, Sturm C. Process-evaluation of tropospheric humidity simulated by general circulation models using water vapor isotopic observations: 2. Using isotopic diagnostics to understand the mid and upper tropospheric moist bias in the tropics and subtropics. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016623] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Berkelhammer M, Risi C, Kurita N, Noone DC. The moisture source sequence for the Madden-Julian Oscillation as derived from satellite retrievals of HDO and H2O. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016803] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Risi C, Bony S, Vimeux F, Frankenberg C, Noone D, Worden J. Understanding the Sahelian water budget through the isotopic composition of water vapor and precipitation. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jd014690] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Camille Risi
- Cooperative Institute for Research in Environmental Sciences; University of Colorado at Boulder; Boulder Colorado USA
- Laboratoire de Météorologie Dynamique; Paris France
| | | | - Françoise Vimeux
- Insitut de Recherche pour le Développement; Laboratoire HydroSciences Montpellier (UMR, CNRS, IRD, UM1, UM2) and Laboratoire des Sciences du Climat et de l'Environnement (UMR CEA-CNRS-UVSQ); Gif-sur-Yvette France
| | - Christian Frankenberg
- Jet Propulsion Laboratory; California Institute of Technology; Pasadena California USA
| | - David Noone
- Cooperative Institute for Research in Environmental Sciences; University of Colorado at Boulder; Boulder Colorado USA
| | - John Worden
- Jet Propulsion Laboratory; California Institute of Technology; Pasadena California USA
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Field RD, Jones DBA, Brown DP. Effects of postcondensation exchange on the isotopic composition of water in the atmosphere. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jd014334] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Robert D. Field
- Department of Physics; University of Toronto; Toronto Canada
| | | | - Derek P. Brown
- Department of Atmospheric and Oceanic Sciences and Cooperative Institute for Research in Environmental Sciences; University of Colorado; Boulder Colorado USA
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Deuterium excess reveals diurnal sources of water vapor in forest air. Oecologia 2010; 165:213-23. [PMID: 20652594 DOI: 10.1007/s00442-010-1721-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 07/01/2010] [Indexed: 10/19/2022]
Abstract
An understanding of atmospheric water vapor content and its isotopic composition is important if we are to be able to model future water vapor dynamics and their potential feedback on future climate change. Here we present diurnal and vertical patterns of water isotope ratios in forest air (δ(2)H(v) and δ(18)O(v)) not observed previously. Water vapor observed at three heights over 3 consecutive days in a coniferous forest in the Pacific Northwest of the United States, shows a stratified nocturnal structure of δ(2)H(v) and δ(18)O(v), with the most positive values consistently observed above the canopy (60 m). Differences between 0.5 m and 60 m range between 2-6‰ for δ(18)O and 20-40‰ for δ(2)H at night. Using a box model, we simulated H(2)O isotope fluxes and showed that the low to high δ(2)H(v) and δ(18)O(v) profiles can be explained by the vapor flux associated with evaporation from the forest floor and canopy transpiration. We used d-excess as a diagnostic tracer to identify processes that contribute to the diurnal variation in atmospheric moisture. Values of d-excess derived from water vapor measurements showed a repeated diel pattern, with the lowest values occurring in the early morning and the highest values occurring at midday. The isotopic composition of rain water, collected during a light rain event in the first morning of our experiment, suggested that considerable below-cloud secondary evaporation occurred during the descent of raindrops. We conclude that atmospheric entrainment appears to drive the isotopic variation of water vapor in the early morning when the convective boundary layer rapidly develops, while evapotranspiration becomes more important in the mid-afternoon as a primary moisture source of water vapor in this forest. Our results demonstrate the interplay between the effects of vegetation and boundary layer mixing under the influence of rain evaporation, which has implications for larger-scale predictions of precipitation across the terrestrial landscape.
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