DOI: 10.1007/s00382-011-1262-3
Scopus记录号: 2-s2.0-84856327905
论文题名: Synoptic and mesoscale controls on the isotopic composition of precipitation in the western United States
作者: Berkelhammer M. ; Stott L. ; Yoshimura K. ; Johnson K. ; Sinha A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2012
卷: 38, 期: 2017-03-04 起始页码: 433
结束页码: 454
语种: 英语
英文关键词: Global hydrologic cycle
; Isotope hydrology
; Model validation
英文摘要: We present a new event-scale catalog of stable isotopic measurements from 5 years of storm events at 4 sites in southern California, which is used to understand the storm to storm controls on the isotopic composition of precipitation and validate the event-scale performance of an isotope-enabled GCM simulation (IsoGSM) (Yoshimura et al. 2008). These analyses are motivated to improve the interpretation of proxy records from this region and provide guidance in testing the skill of GCMs in reproducing the hydrological variability in the western US. We find that approximately 40% of event-scale isotopic variability arises from the percentage of precipitation that is convective and the near surface relative humidity in the days prior to the storms landfall. The additional isotopic variability arises from the fact that storms arriving from different source regions advect moisture of distinct isotopic compositions. We show using both field correlation and Lagrangian trajectory analysis that the advection of subtropical and tropical moisture is important in producing the most isotopically enriched precipitation. The isotopic catalog is then used along with satellite-derived δD retrievals of atmospheric moisture to benchmark the performance of the IsoGSM model for the western US. The model is able to successfully replicate the observed isotopic variability suggesting that it is closely reproducing the moisture transport and storm track dynamics that drive the large storm-to-storm isotopic range. Notably, we find that an increase in moisture flux from the central tropical Pacific leads to a convergence of isotopically enriched water vapor in the subtropics and consequently an increase in δ18O of precipitation at sites along the entire west coast. Changes in poleward moisture flux from the central Tropical Pacific have important implications for both the global hydrological cycle and regional precipitation amounts and we suggest such changes can be captured through instrumental and proxy-reconstruction of the spatiotemporal isotopic patterns in the precipitation along the west coast of the US. © 2011 Springer-Verlag. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/55385
Appears in Collections: 过去全球变化的重建
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作者单位: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, United States; Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States; Center for Climate System Research, University of Tokyo, Tokyo, Japan; Earth Systems Science, University of California, Irvine, CA, United States; Department of Earth Sciences, California State University, Dominguez Hills, CA, United States; Scripps Institute of Oceanography, University of California, San Diego La Jolla, CA, United States
Recommended Citation:
Berkelhammer M.,Stott L.,Yoshimura K.,et al. Synoptic and mesoscale controls on the isotopic composition of precipitation in the western United States[J]. Climate Dynamics,2012-01-01,38(2017-03-04)