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Title: Improved high‐resolution global and regionalized isoscapes of δ18O , δ2H and d‐excess in precipitation
Abstract

Patterns ofδ18O andδ2H in Earth's precipitation provide essential scientific data for use in hydrological, climatological, ecological and forensic research. Insufficient global spatial data coverage promulgated the use of gridded datasets employing geostatistical techniques (isoscapes) for spatiotemporally coherent isotope predictions. Cluster‐based isoscape regionalization combines the advantages of local or regional prediction calibrations into a global framework. Here we present a revision of a Regionalized Cluster‐Based Water Isotope Prediction model (RCWIP2) incorporating new isotope data having extensive spatial coverage and a wider array of predictor variables combined with high‐resolution gridded climatic data. We introduced coupling ofδ18O andδ2H (e.g.,d‐excess constrained) in the model predictions to prevent runaway isoscapes when each isotope is modelled separately and cross‐checked observed versus modelledd‐excess values. We improved model error quantification by adopting full uncertainty propagation in all calculations. RCWIP2 improved the RMSE over previous isoscape models by ca. 0.3 ‰ forδ18O and 2.5 ‰ forδ2H with an uncertainty <1.0 ‰ forδ18O and < 8 ‰ forδ2H for most regions of the world. The determination of the relative importance of each predictor variable in each ecoclimatic zone is a new approach to identify previously unrecognized climatic drivers on mean annual precipitationδ18O andδ2H. The improved RCWIP2 isoscape grids and maps (season, monthly, annual, regional) are available for download athttps://isotopehydrologynetwork.iaea.org.

 
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NSF-PAR ID:
10449646
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Hydrological Processes
Volume:
35
Issue:
6
ISSN:
0885-6087
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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