• Aldrian, E., L. Dümenil-Gates, D. Jacob, R. Podzun, and D. Gunawan, 2004: Long-term simulation of Indonesian rainfall with the MPI regional model. Climate Dyn., 22 , 795814.

    • Search Google Scholar
    • Export Citation
  • Bradley, R. S., M. Vuille, D. Hardy, and L. G. Thompson, 2003: Low latitude ice cores record Pacific sea surface temperatures. Geophys. Res. Lett., 30 .1174, doi:10.1029/2002GL016546.

    • Search Google Scholar
    • Export Citation
  • Chou, S. C., A. M. B. Nunes, and I. F. A. Cavalcanti, 2000: Extended range forecasts over South America using the regional eta model. J. Geophys. Res., 105 , 1014710160.

    • Search Google Scholar
    • Export Citation
  • Costa, M. H., and J. A. Foley, 1998: A comparison of precipitation datasets for the Amazon basin. Geophys. Res. Lett., 25 , 155158.

  • Dall’Olio, A., 1976: A composicão isotopica das precipitacãos do Brasil: Modelos isotermicos e a influencia da evapotranspiracão na Basina Amazonica. M.S. thesis, Dept. of Meteorology, University of São Paulo, 180 pp.

  • Dansgaard, W., 1964: Stable isotopes in precipitation. Tellus, 16 , 436468.

  • Doherty, R., M. Hulme, and C. Jones, 1999: A gridded reconstruction of land and ocean precipitation for the extended tropics from 1974 to 1994. Int. J. Climatol., 19 , 119142.

    • Search Google Scholar
    • Export Citation
  • ECMWF, cited. 2003: ECMWF 40 Years Re-Analysis, monthly means. [Available online at http://data.ecmwf.int/data/d/era40_mnth/.].

  • Ginot, P., M. Schwikowski, U. Schotterer, W. Stichler, H. W. Gäggeler, B. Francou, R. Gallaire, and B. Pouyaud, 2002: Potential for climate variability reconstruction from Andean glaciochemical records. Ann. Glaciol., 35 , 443450.

    • Search Google Scholar
    • Export Citation
  • Gonfiantini, R., M. Roche, J. Olivry, J. Fontes, and G. Zuppi, 2001: The altitude effect on the isotopic composition of tropical rains. Chem. Geol., 181 , 147167.

    • Search Google Scholar
    • Export Citation
  • Hastenrath, S., 1997: Annual cycle of upper air circulation and convective activity over the tropical Americas. J. Geophys. Res., 102 , 42674274.

    • Search Google Scholar
    • Export Citation
  • Henderson-Sellers, A., K. McGuffie, and H. Zhang, 2002: Stable isotopes as validation tools for global climate model predictions of the impact of Amazonian deforestation. J. Climate, 15 , 26642677.

    • Search Google Scholar
    • Export Citation
  • Hoffmann, G., 2003: Taking the pulse of the tropical water cycle. Science, 301 , 776777.

  • Hoffmann, G., M. Werner, and M. Heimann, 1998: Water isotope module of the ECHAM atmospheric general circulation model: A study on timescales from days to several years. J. Geophys. Res., 103 , 1687116896.

    • Search Google Scholar
    • Export Citation
  • Hoffmann, G., and Coauthors, 2003: Coherent isotope history of Andean ice cores over the last century. Geophys. Res. Lett., 30 .1179, doi:10.1029/2002GL014870.

    • Search Google Scholar
    • Export Citation
  • Huffman, G., and D. Bolvin, cited. 2004: GPCP version 2 combined precipitation data set. [Available online at http://www.ncdc.noaa.gov/oa/wmo/wdcamet-ncdc.html#version2.].

  • Hulme, M., T. J. Osborn, and T. C. Johns, 1998: Precipitation sensitivity to global warming: Comparison of observations with HadCM2 simulations. Geophys. Res. Lett., 25 , 33793382.

    • Search Google Scholar
    • Export Citation
  • IAEA, and WMO, cited. 2001: The Global Network of Isotopes in Precipitation (GNIP) database. [Available online at http://isohis.iaea.org].

  • Lai, C-T., J. R. Ehleringer, B. J. Bond, and K. T. Paw U, 2006: Contributions of evaporation, isotopic non-steady state transpiration and atmospheric mixing on the δ18O of water vapour in Pacific Northwest coniferous forests. Plant Cell Environ., 29 , 7794.

    • Search Google Scholar
    • Export Citation
  • Lenters, J. D., and K. H. Cook, 1995: Simulation and diagnosis of the regional summertime precipitation climatology of South America. J. Climate, 8 , 29883005.

    • Search Google Scholar
    • Export Citation
  • Lenters, J. D., and K. H. Cook, 1997: On the origin of the Bolivian high and related circulation features of the South American climate. J. Atmos. Sci., 54 , 656678.

    • Search Google Scholar
    • Export Citation
  • Lenters, J. D., and K. H. Cook, 1999: Summertime precipitation variability in South America: Role of the large-scale circulation. Mon. Wea. Rev., 127 , 409431.

    • Search Google Scholar
    • Export Citation
  • Merlivat, L., and J. Jouzel, 1979: Global climatic interpretation of the deuterium–oxygen 18 relationship for precipitation. J. Geophys. Res., 84 , 50295033.

    • Search Google Scholar
    • Export Citation
  • Nordeng, T., 1994: Extended versions of the convective parameterization scheme at ECMWF and then-impact on the mean and transient activity of the model in the tropics. ECMWF Tech. Memo. 206, 7 pp.

  • Ramirez, E., and Coauthors, 2003: A new Andean deep ice core from Nevado Illimani (6350 m), Bolivia. Earth Planet. Sci. Lett., 212 , 337350.

    • Search Google Scholar
    • Export Citation
  • Rao, V. B., I. F. A. Cavalcanti, and K. Hada, 1996: Annual variation of rainfall over Brazil and water vapor characteristics over South America. J. Geophys. Res., 101 , 2653926552.

    • Search Google Scholar
    • Export Citation
  • Rayner, N. A., E. B. Horton, D. E. Parker, C. K. Folland, and R. B. Hackett, 1996: Version 2.2 of the Global Sea-Ice and Sea Surface Temperature Data Set, 1903–1994. Climate Research Tech. Note 74, Hadley Centre for Climate Prediction and Research, 50 pp. [Available online at http://hadobs.metoffice.com/gisst/crtn74.pdf.].

  • Roche, M., R. Gonfiantini, J. Fontes, N. Abasto, and L. Noriega, 1999: The isotopic composition of precipitation on the Andes and Amazon of Bolivia. Extended Abstracts, Int. Symp. on Isotopes in Hydrology, Vienna, Austria, International Atomic Energy Agency, 1–10.

  • Rojas, M., and A. Seth, 2003: Simulation and sensitivity in a nested modeling system for South America. Part II: GCM boundary forcing. J. Climate, 16 , 24542471.

    • Search Google Scholar
    • Export Citation
  • Salati, E., A. Dall’Olio, E. Matsui, and J. Gat, 1979: Recycling of water in the Amazon basin: An isotopic study. Water Resour. Res., 15 , 12501257.

    • Search Google Scholar
    • Export Citation
  • Schmidt, G. A., G. Hoffmann, D. T. Shindell, and Y. Hu, 2005: Modeling atmospheric stable water isotopes and the potential for constraining cloud processes and stratosphere-troposphere water exchange. J. Geophys. Res., 110 .D21314, doi:10.1029/2005JD005790.

    • Search Google Scholar
    • Export Citation
  • Seth, A., and M. Rojas, 2003: Simulation and sensitivity in a nested modeling system for South America. Part I: Reanalyses boundary forcing. J. Climate, 16 , 24372453.

    • Search Google Scholar
    • Export Citation
  • Siegenthaler, U., and H. Oeschger, 1980: Correlation of 18O in precipitation with temperature and altitude. Nature, 285 , 314317.

  • Sturm, K., G. Hoffmann, B. Langmann, and W. Stichler, 2005: Simulation of δ18O in precipitation by the regional circulation model REMOiso. Hydrol. Processes, 19 , 34253444.

    • Search Google Scholar
    • Export Citation
  • Sturm, K., F. Vimeux, and G. Krinner, 2007: The South American monsoon recorded in stable water isotopes. J. Geophys. Res., in press.

  • Thompson, L. G., E. Mosley-Thompson, and K. A. Henderson, 2000: Ice-core palaeoclimate records in tropical South America since the Last Gacial Maximum. J. Quat. Sci., 15 , 377394.

    • Search Google Scholar
    • Export Citation
  • Vera, C., 2004: Introduction to the South American Low-Level Jet Experiment (SALLJEX). CLIVAR Exchanges, Vol. 9, No. 1, International CLIVAR Project Office, Southampton, United Kingdom, 3–4.

  • Vernekar, A. D., B. P. Kirtman, and M. J. Fennessy, 2003: Low-level jets and their effects on the South American summer climate as simulated by the NCEP Eta Model. J. Climate, 16 , 297311.

    • Search Google Scholar
    • Export Citation
  • Vimeux, F., R. Gallaire, S. Bony, G. Hoffmann, and J. C. H. Chiang, 2005: What are the controls on δD in precipitation in the Zongo Valley (Bolivia)? Implications for the Illimani ice core interpretation. Earth Planet. Sci. Lett., 240 , 205220.

    • Search Google Scholar
    • Export Citation
  • Vogel, J., J. Lerman, and W. Mook, 1975: Natural isotopes in surface and groundwater from Argentina. Hydrol. Sci. Bull., 20 , 203221.

  • von Storch, H., H. Langenberg, and F. Feser, 2000: A spectral nudging technique for dynamical downscaling purposes. Mon. Wea. Rev., 128 , 36643673.

    • Search Google Scholar
    • Export Citation
  • Vuille, M., R. S. Bradley, M. Werner, R. Healy, and F. Keimig, 2003a: Modeling δ18O in precipitation over the tropical Americas: 1. Interannual variability and climatic controls. J. Geophys. Res., 108 .4174, doi:10.1029/2001JD002038.

    • Search Google Scholar
    • Export Citation
  • Vuille, M., R. S. Bradley, R. Healy, M. Werner, D. R. Hardy, L. G. Thompson, and F. Keimig, 2003b: Modeling δ18O in precipitation over the tropical Americas: 2. Simulation of the stable isotope signal in Andean ice cores. J. Geophys. Res., 108 .4175, doi:10.1029/2001JD002039.

    • Search Google Scholar
    • Export Citation
  • Werner, M., U. Mikolajewicz, M. Heimann, and G. Hoffmann, 2000: Borehole versus isotope temperatures on Greenland: Seasonality does matter. Geophys. Res. Lett., 27 , 723726.

    • Search Google Scholar
    • Export Citation
  • Willmott, C., and K. Matsuura, cited. 2001: Terrestrial air temperature and precipitation: Monthly and annual time series (1950–1999). [Available online at http://climate.geog.udel.edu/climate/html_pages/README.ghcn_ts2.html.].

  • Xie, P., and P. Arkin, cited. 2002: CPC Merged Analysis of Precipitation (CMAP). [Available online at http://www.cgd.ucar.edu/cas/catalog/surface/precip/arkin.html.].

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 3 3 3
PDF Downloads 1 1 1

Simulation of the Stable Water Isotopes in Precipitation over South America: Comparing Regional to Global Circulation Models

View More View Less
  • 1 Laboratoire de Glaciologie et Géophysique de I’Environnement, CNRS/OSUG, Grenoble, France
  • | 2 Laboratoire des Sciences du Climate et de I’Environnement, CEA, Saclay, France
  • | 3 Max-Planck-Institut für Meteorologie, MPG, Hamburg, Germany
Restricted access

Abstract

A simulation of the stable water isotope cycle over South America by the regional circulation model REMOiso is discussed. The performance of the regional model, with a resolution of 0.5° (∼55 km), is compared to simulations by the global circulation model ECHAMiso at two coarser resolutions and evaluated against observations of precipitation and δ18O.

Here REMOiso is demonstrated to reproduce reasonably well climatic and isotopic features across South America. This paper explores further insights of δ18O as a climate proxy, based on REMOiso’s improvements as compared to ECHAMiso. In particular, the authors focus on the seasonal variation of the amount effect (δ18O decrease with precipitation amounts) and the anomalous δ18O continental gradient across the Amazon basin, as inferred from the REMOiso, ECHAMiso, and GNIP datasets. The finer resolution of topography in REMOiso enables a detailed analysis of the altitude effect: not only the first, but also the second derivative of δ18O with altitude is considered. It appears that high-altitude grid cells show an isotopic signature similar to Rayleigh distillation, in accordance with experimental studies. Finally, a Lagrangian reference frame is adopted to describe the evolution of δ18O in precipitation along its trajectory, in order to relate the simulation analysis to the fractionation mechanisms. This confirms that the amount effect, via Rayleigh distillation processes, is dominant during the wet season. During the dry season, the δ18O in precipitation is controlled by isotopic reequilibration of rain droplets with surrounding vapor, reflecting the impact of nonfractionating transpiration by the vegetation.

* Current affiliation: Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway

Corresponding author address: Christophe Sturm, Bjerknes Centre for Climate Research, University of Bergen, Strandgaten 29, NO-5013, Bergen, Norway. Email: kristof.sturm@bjerrknes.uib.no

Abstract

A simulation of the stable water isotope cycle over South America by the regional circulation model REMOiso is discussed. The performance of the regional model, with a resolution of 0.5° (∼55 km), is compared to simulations by the global circulation model ECHAMiso at two coarser resolutions and evaluated against observations of precipitation and δ18O.

Here REMOiso is demonstrated to reproduce reasonably well climatic and isotopic features across South America. This paper explores further insights of δ18O as a climate proxy, based on REMOiso’s improvements as compared to ECHAMiso. In particular, the authors focus on the seasonal variation of the amount effect (δ18O decrease with precipitation amounts) and the anomalous δ18O continental gradient across the Amazon basin, as inferred from the REMOiso, ECHAMiso, and GNIP datasets. The finer resolution of topography in REMOiso enables a detailed analysis of the altitude effect: not only the first, but also the second derivative of δ18O with altitude is considered. It appears that high-altitude grid cells show an isotopic signature similar to Rayleigh distillation, in accordance with experimental studies. Finally, a Lagrangian reference frame is adopted to describe the evolution of δ18O in precipitation along its trajectory, in order to relate the simulation analysis to the fractionation mechanisms. This confirms that the amount effect, via Rayleigh distillation processes, is dominant during the wet season. During the dry season, the δ18O in precipitation is controlled by isotopic reequilibration of rain droplets with surrounding vapor, reflecting the impact of nonfractionating transpiration by the vegetation.

* Current affiliation: Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway

Corresponding author address: Christophe Sturm, Bjerknes Centre for Climate Research, University of Bergen, Strandgaten 29, NO-5013, Bergen, Norway. Email: kristof.sturm@bjerrknes.uib.no

Save