DOI: 10.1007/s00382-014-2074-z
Scopus记录号: 2-s2.0-84942077011
论文题名: Characterizing atmospheric circulation signals in Greenland ice cores: insights from a weather regime approach
作者: Ortega P. ; Swingedouw D. ; Masson-Delmotte V. ; Risi C. ; Vinther B. ; Yiou P. ; Vautard R. ; Yoshimura K.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 43, 期: 2017-09-10 起始页码: 2585
结束页码: 2605
语种: 英语
英文关键词: Greenland climate variability
; Ice cores
; Isotope reanalyses
; Modes of climate variability
; North Atlantic weather regimes
; Water stable isotopes
英文摘要: Greenland ice cores offer seasonal to annual records of δ18O, a proxy for precipitation-weighted temperature, over the last few centuries to millennia. Here, we investigate the regional footprints of the North Atlantic weather regimes on Greenland isotope and climate variability, using a compilation of 22 different shallow ice-cores and the atmospheric pressure conditions from the twentieth century reanalysis (20CR). As a first step we have verified that the leading modes of winter and annual δ18O are well correlated with oceanic (Atlantic multidecadal oscillation) and atmospheric [North Atlantic oscillation (NAO)] indices respectively, and also marginally with external forcings, thus confirming earlier studies. The link between weather regimes and Greenland precipitation, precipitation-weighted temperature and δ18O is further explored by using an isotope simulation from the LMDZ-iso model, where the 3-dimensional wind fields are nudged to those of 20CR. In winter, the NAO+ and NAO− regimes in LMDZ-iso produce the largest isotopic changes over the entire Greenland region, with maximum anomalies in the South. Likewise, the Scandinavian blocking and the Atlantic ridge also show remarkable imprints on isotopic composition over the region. To assess the robustness and model dependency of our findings, a second isotope simulation from the isotopic model is also explored. The percentage of Greenland δ18O variance explained by the ensemble of weather regimes is increased by a factor near two in both LMDZ-iso and IsoGSM when compared to the contribution of the NAO index only. Similarly, weather regimes provide a net gain in the δ18O variance explained of similar magnitude for the whole set of ice core records. Greenland δ18O also appears to be locally affected by the low-frequency variations in the centres of action of the weather regimes, with clearer imprints in the LMDZ-iso simulation. This study opens the possibility for reconstructing past changes in the frequencies of occurrence of the weather regimes, which would rely on the sensitive regions identified here, and the use of additional proxies over the North Atlantic region. © 2014, Springer-Verlag Berlin Heidelberg. 资助项目: ANR, Agence Nationale de la Recherche
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54509
Appears in Collections: 过去全球变化的重建
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作者单位: LSCE/IPSL, CEA Saclay, Gif-sur-Yvette, France; LMD/IPSL, CNRS, Paris, France; Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark; Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
Recommended Citation:
Ortega P.,Swingedouw D.,Masson-Delmotte V.,et al. Characterizing atmospheric circulation signals in Greenland ice cores: insights from a weather regime approach[J]. Climate Dynamics,2014-01-01,43(2017-09-10)