Spatial distribution of δ18O in meteoric precipitation

Proxy data reflecting the oxygen isotope composition of meteoric precipitation (δ18Oppt) are widely used in reconstructions of continental paleoclimate and paleohydrology. However, actual geographic variation in modern water compositions is difficult to estimate from often sparse data. A first step toward understanding the geologic pattern of change in δ18Oppt is to describe the modern distribution in terms of principal geographic parameters. To this end, we empirically model relationships between 18O in modern precipitation and latitude and altitude. We then identify geographic areas where large-scale vapor transport patterns give rise to significant deviations from model δ18Oppt compositions based on latitude and altitude. Model value and residual grids are combined to derive a high-resolution global map of δ18Oppt that can serve as a spatial reference against which proxy data for paleoprecipitation can be compared. Reiteration of the procedure outlined here, for paleo-δ18Oppt data, may illuminate past changes in the climatic and physiographic parameters controlling the distribution of δ18O regimes.

[1]  M. Heimann,et al.  Water isotope modeling in the Asian monsoon region , 1997 .

[2]  R. Pierrehumbert,et al.  Huascaran δ18O as an indicator of tropical climate during the Last Glacial Maximum , 1999 .

[3]  J. Jouzel,et al.  Evidence for general instability of past climate from a 250-kyr ice-core record , 1993, Nature.

[4]  W. Dansgaard.  The O18-abundance in fresh water , 1954 .

[5]  J. Peixoto,et al.  Physics of climate , 1992 .

[6]  A. Dutton.  Groundwater Isotopic Evidence for Paleorecharge in U.S. High Plains Aquifers , 1995, Quaternary Research.

[7]  W. Clyde,et al.  Intra-tooth variations in δ18O (PO4) of mammalian tooth enamel as a record of seasonal variations in continental climate variables , 1998 .

[8]  R. C. Reynolds,et al.  Topographic development of the Southern Alps recorded by the isotopic composition of authigenic clay minerals, South Island, New Zealand , 1999 .

[9]  J. Harris,et al.  Stable isotope composition of waters in southeastern California 1. Modern precipitation , 1992 .

[10]  R. Hepple,et al.  Hematite and Calcite Coatings on Fossil Vertebrates , 1998 .

[11]  W. Dansgaard.  Stable isotopes in precipitation , 1964 .

[12]  J. Jouzel,et al.  A general circulation model of water isotope cycles in the atmosphere , 1984, Nature.

[13]  E. Mosley‐Thompson,et al.  Late Glacial Stage and Holocene Tropical Ice Core Records from Huascar�n, Peru , 1995, Science.

[14]  J. Jouzel,et al.  Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica , 1999, Nature.

[15]  David A. Pickett,et al.  A High-Resolution Record of Holocene Climate Change in Speleothem Calcite from Cold Water Cave, Northeast Iowa , 1992, Science.

[16]  E. Grossman,et al.  Oxygen isotopes in meteoric calcite cements as indicators of continental paleoclimate , 1991 .

[17]  J. Zachos,et al.  Stable isotope stratigraphy and paleoclimatology of the Paleogene Bighorn Basin (Wyoming, USA) , 1995 .

[18]  J. Fontes,et al.  The altitude effect on the isotopic composition of tropical rains , 2001 .

[19]  R. Amundson,et al.  Isotopic evidence for shifts in atmospheric circulation patterns during the late Quaternary in mid–North America , 1996 .

[20]  C. Covey,et al.  A model of oxygen isotope composition of precipitation: Implications for paleoclimate data , 1984 .

[21]  B. Wolfe,et al.  Influence of Changing Atmospheric Circulation on Precipitation δ18O–Temperature Relations in Canada during the Holocene , 1996, Quaternary Research.

[22]  J. R. O'neil,et al.  The correlation between 18O/16O ratios of meteoric water and surface temperature: its use in investigating terrestrial climate change over geologic time , 1999 .

[23]  R. Koster,et al.  Stable water isotope behavior during the last glacial maximum: A general circulation model analysis , 1994 .

[24]  Z. Sharp,et al.  Fossil isotope records of seasonal climate and ecology: Straight from the horse's mouth , 1998 .

[25]  C. Chamberlain,et al.  Reconstructing the paleotopography of mountain belts from the isotopic composition of authigenic minerals , 2000 .

[26]  W. Simpkins.  Isotopic composition of precipitation in central Iowa , 1995 .

[27]  E. Bettis,et al.  Evidence for increased cool season moisture during the middle Holocene , 1999 .

[28]  P. Koch,et al.  Paleocene–Eocene climatic variation in western North America: Evidence from the δ18O of pedogenic hematite , 1999 .

[29]  J. Bryant,et al.  Oxygen isotope partitioning between phosphate and carbonate in mammalian apatite , 1996 .

[30]  E. Boyle.  Cool tropical temperatures shift the global δ18O‐T relationship: An explanation for the ice core δ18O ‐ borehole thermometry conflict? , 1997 .