DOI: 10.1016/j.epsl.2017.10.035
Scopus记录号: 2-s2.0-85033706708
论文题名: Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores
作者: Miller M.F.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 481 起始页码: 316
结束页码: 327
语种: 英语
英文关键词: 17O-excess
; Antarctica
; ice cores
; precipitation
; water isotopologues
Scopus关键词: Dust
; Humidity control
; Isotopes
; Precipitation (chemical)
; Precipitation (meteorology)
; Snow
; Supersaturation
; Antarctica
; Ice core
; Relative humidity changes
; Temperature differential
; Temporal and spatial scale
; Water isotopologues
; West antarctic ice sheets
; ^17O-excess
; Ice
; accumulation
; Holocene
; ice core
; oxygen isotope
; paleoclimate
; parameterization
; precipitation (climatology)
; relative humidity
; snow
; Antarctic Ice Sheet
; Antarctica
; West Antarctic Ice Sheet
; West Antarctica
英文摘要: The relative abundance of 17O in meteoric precipitation is usually reported in terms of the 17O-excess parameter. Variations of 17O-excess in Antarctic precipitation and ice cores have hitherto been attributed to normalised relative humidity changes at the moisture source region, or to the influence of a temperature-dependent supersaturation-controlled kinetic isotope effect during in-cloud ice formation below −20 °C. Neither mechanism, however, satisfactorily explains the large range of 17O-excess values reported from measurements. A different approach, based on the regression characteristics of 103ln(1+δ17O) versus 103ln(1+δ18O), is applied here to previously published isotopic data sets. The analysis indicates that clear-sky precipitation (‘diamond dust’), which occurs widely in inland Antarctica, is characterised by an unusual relative abundance of 17O, distinct from that associated with cloud-derived, synoptic snowfall. Furthermore, this distinction appears to be largely preserved in the ice core record. The respective mass contributions to snowfall accumulation – on both temporal and spatial scales – provides the basis of a simple, first-order explanation for the observed oxygen triple-isotope ratio variations in Antarctic precipitation, surface snow and ice cores. Using this approach, it is shown that precipitation during the last major deglaciation, both in western Antarctica at the West Antarctic Ice Sheet (WAIS) Divide and at Vostok on the eastern Antarctic plateau, consisted essentially of diamond dust only, despite a large temperature differential (and thus different water vapour supersaturation conditions) at the two locations. In contrast, synoptic snowfall events dominate the accumulation record throughout the Holocene at both sites. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110161
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Planetary and Space Sciences, School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom; British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
Recommended Citation:
Miller M.F.. Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores[J]. Earth and Planetary Science Letters,2018-01-01,481