کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4736534 1640905 2011 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Noble gases as proxies of mean ocean temperature: sensitivity studies using a climate model of reduced complexity
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Noble gases as proxies of mean ocean temperature: sensitivity studies using a climate model of reduced complexity
چکیده انگلیسی

Past global mean ocean temperature may be reconstructed from measurements of atmospheric noble gas concentrations in ice core bubbles. Assuming conservation of noble gases in the atmosphere-ocean system, the total concentration within the ocean mostly depends on solubility which itself is temperature dependent. Therefore, the colder the ocean, the more gas can be dissolved and the less remains in the atmosphere. Here, the characteristics of this novel paleoclimatic proxy are explored by implementing krypton, xenon, argon, and N2 into a reduced-complexity climate model. The relationship between noble gas concentrations and global mean ocean temperature is investigated and their sensitivities to changes in ocean volume, ocean salinity, sea-level pressure and geothermal heat flux are quantified. We conclude that atmospheric noble gas concentrations are suitable proxies of global mean ocean temperature. Changes in ocean volume need to be considered when reconstructing ocean temperatures from noble gases. Calibration curves are provided to translate ice-core measurements of krypton, xenon, and argon into a global mean ocean temperature change. Simulated noble gas-to-nitrogen ratios for the last glacial maximum are δKratm = −1.10‰, δXeatm = −3.25‰, and δAratm = −0.29‰. The uncertainty of the krypton calibration curve due to uncertainties of the ocean saturation concentrations is estimated to be ±0.3 °C. An additional ±0.3 °C uncertainty must be added for the last deglaciation and up to ±0.4 °C for earlier transitions due to age-scale uncertainties in the sea-level reconstructions. Finally, the fingerprint of idealized Dansgaard-Oeschger events in the atmospheric krypton-to-nitrogen ratio is presented. A δKratm change of up to 0.34‰ is simulated for a 2 kyr Dansgaard-Oeschger event, and a change of up to 0.48‰ is simulated for a 4 kyr event.


► With a climate model, noble gases as proxies of mean ocean temperature are tested.
► Past atmospheric noble gas concentrations can be measured in ice cores.
► It is found that noble gases are suitable proxies of global mean ocean temperature.
► The sea-level history must be taken into account in the temperature reconstruction.
► Sea ice has the potential to decouple the noble gas from the temperature signal.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Quaternary Science Reviews - Volume 30, Issues 25–26, December 2011, Pages 3728–3741
نویسندگان
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