Modeling the water isotopes in Greenland precipitation 1959–2001 with the meso-scale model REMO-iso

• Published in: Journal of Geophysical Research
• Main Authors: Sjolte, J., Hoffmann, G., Johnsen, S. J., Vinther, B. M., Masson-delmotte, V., Sturm, C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-Blackwell 2011
• Subjects: Meteorology and Atmospheric Sciences; Greenland; Remo; Svalbard; Greenland ice core; ice core; Iceland; North Atlantic; North Atlantic oscillation
• Online Access: https://lup.lub.lu.se/record/b7379750-d336-4ef0-9fb1-897afe8c45b6; https://doi.org/10.1029/2010JD015287

Ice core studies have proved thed18O in Greenland precipitation to be correlated to thephase of the North Atlantic Oscillation (NAO). This subject has also been investigated inmodeling studies. However, these studies have either had severe biases in thed18O levels,or have not been designed to be compared directly with observations. In this study wenudge a meso‐scale climate model fitted with stable water isotope diagnostics (REMO‐iso)to follow the actual weather patterns for the period 1959–2001. We evaluate thissimulation using meteorological observations from stations along the Greenland coast,andd18O from several Greenland ice core stacks and Global Network In Precipitation(GNIP) data from Greenland, Iceland and Svalbard. The REMO‐iso output explains up to40% of the interannuald18O variability observed in ice cores, which is comparable to themodel performance for precipitation. In terms of reproducing the observed variabilitythe global model, ECHAM4‐iso performs on the same level as REMO‐iso. However,REMO‐iso has smaller biases ind18O and improved representation of the observed spatiald18O‐temperature slope compared to ECHAM4‐iso. Analysis of the main modes of wintervariability ofd18O shows a coherent signal in Central and Western Greenland similarto results from ice cores. The NAO explains 20% of the leadingd18O pattern. Based on themodel output we suggest that methods to reconstruct the NAO from Greenland ice coresemploy bothd18O and accumulation records