Paleoclimatic tracers: An investigation using an atmospheric general circulation model under ice age conditions. 2. Water isotopes

Journal Article · Sat Feb 20 00:00:00 EST 1993 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JD01920· OSTI ID:6721324

Joussaume, S ^[1]; Jouzel, J ^[2]

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1. Centre National de la Recherche Scientifique, Paris (France)
2. Commissariat a l'Energie Atomique, Saclay (France) Centre National de la Recherche Scientifique, Grenoble (France)

The linear relationship observed between the water isotopic contents of precipitation and surface air temperatures leads to the use of the water isotopes, H[sub 2][sup 18]O and HDO, in paleoclimatology. Applied to the measurements of the isotopic content of paleowaters, like groundwaters and deep ice cores, this relationship is used to infer paleotemperatures. However, this interpretation of paleo-isotopic contents is only valid if the isotope-temperature relationship is not affected by climate change. To address this problem, the authors have developed a water isotope modeling inside an atmospheric general circulation model (AGCM) and performed simultations of both the present-day and Last Glacial Maximum (LGM) climatic conditions. AGCM are indeed the only appropriate tools able to account the whole complexity of the atmospheric circulation. For the present-day climate, preliminary results for January were presented by Joussaume et al. (1984) and are complemented by new simulations performed for both February and August climatic conditions with a higher-resolution version of the model. Model results are well corroborated by observations. They also exhibit some effects of the atmospheric circulation on the isotopic fields. For the simulated LGM climate, the model results compare well with paleoclimatic data of water isotopic contents, except for a higher than observed spatial variability. The overall patterns of the simulated [delta][sup 18]O-temperature relationship for the LGM climate are practically unchanged, which tends to comfort the use of water isotopes in paleoclimatology. However, concerning the deuterium excess, i.e., the relationship between oxyen 18 and deuterium, the model results are not sufficiently valid to allow a discussion of the use of deuterium excess in paleoclimatology. 46 refs., 14 figs., 7 tabs.

• OSTI ID: 6721324
• Journal Information: Journal of Geophysical Research; (United States), Vol. 98:D2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
EARTH ATMOSPHERE
GENERAL CIRCULATION MODELS
GLACIERS
SAMPLING
OXYGEN 18
ECOLOGICAL CONCENTRATION
AIR
ATMOSPHERIC CIRCULATION
DEUTERIUM
ICE
ISOTOPES
PALEOCLIMATOLOGY
PALEOTEMPERATURE
PRECIPITATION
SURFACE AIR
WATER
EVEN-EVEN NUCLEI
FLUIDS
GASES
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
NUCLEI
ODD-ODD NUCLEI
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PALEONTOLOGY
SEPARATION PROCESSES
STABLE ISOTOPES
540110*