THE CLIMATE SIGNAL IN THE STABLE ISOTOPES OF SNOW FROM SUMMIT, GREENLAND - RESULTS OF COMPARISONS WITH MODERN CLIMATE OBSERVATIONS

Recent efforts to link the isotopic composition of snow in Greenland w ith meteorological and climatic parameters have indicated that relativ ely local information such as observed annual temperatures from coasta l Greenland sites, as well as more synoptic scale features such as the North Atlantic Oscillation (NAG) and the temperature seesaw between J akobshaven, Greenland, and Oslo, Norway, are significantly correlated with delta(18)O and delta D values from the past few hundred years mea sured in ice cores. In this study we review those efforts and then use a new record of isotope values from the Greenland Ice Sheet Project 2 and Greenland Ice Core Project sites at Summit, Greenland, to compare with meteorological and climatic parameters. This new record consists of six individual annually resolved isotopic records which have been average to produce a Summit stacked isotope record. The stacked record is significantly correlated with local Greenland temperatures over th e past century (r = 0.471), as well as a number of other records inclu ding temperatures and pressures from specific locations as well as tem perature and pressure patterns such as the temperature seesaw and the North Atlantic Oscillation. A multiple linear regression of the stacke d isotope record with a number of meteorological and climatic paramete rs in the North Atlantic region reveals that five variables contribute significantly to the variance in the isotope record: winter NAG, sola r irradiance (as recorded by sunspot numbers), average Greenland coast al temperature, sea surface temperature in the moisture source region for Summit (30 degrees-20 degrees N), and the annual temperature seesa w between Jakobshaven and Oslo. Combined, these variables yield a corr elation coefficient of r = 0.71, explaining half of the variance in th e stacked isotope record.