Stable isotope stacks from GRIP and GISP ice cores

Recent efforts to link the isotopic composition of snow in Greenland with meteorological and climatic parameters have indicated that relatively local information such as observed annual temperatures from coastal Greenland sites, as well as more synoptic scale features such as the North Atlantic Oscillation (NAO) and the temperature seesaw between Jakobshaven, Greenland, and Oslo, Norway, are significantly correlated with d18O and dD values from the past few hundred years measured 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 the past century (r=0.471), as well as a number of other records including temperatures and pressures from specific locations as well as temperature and pressure patterns such as the temperature seesaw and the North Atlantic Oscillation. A multiple linear regression of the stacked isotope record with a number of meteorological and climatic parameters in the North Atlantic region reveals that five variables contribute significantly to the variance in the isotope record: winter NAO, solar irradiance (as recorded by sunspot numbers), average Greenland coastal temperature, sea surface temperature in the moisture source region for Summit (30°-20°N), and the annual temperature seesaw between Jakobshaven and Oslo. Combined, these variables yield a correlation coefficient of r=0.71, explaining half of the variance in the stacked isotope record.

过往将格陵兰雪层同位素组成与气象、气候参数建立关联的研究表明，诸如格陵兰沿岸站点实测年温这类局地信息，以及北大西洋涛动（North Atlantic Oscillation, NAO）、格陵兰雅各布港与挪威奥斯陆间温度跷跷板这类天气尺度特征，均与近数百年间冰芯（ice cores）测得的d18O与dD值存在显著相关性。本研究首先梳理了此类研究进展，随后利用取自格陵兰冰盖顶端（Summit）的格陵兰冰盖计划2（Greenland Ice Sheet Project 2）与格陵兰冰芯计划（Greenland Ice Core Project）站点的同位素新记录，与气象、气候参数开展对比分析。该新记录包含6条独立的年分辨率同位素序列，经平均整合后得到格陵兰冰盖顶端堆叠同位素记录。该堆叠记录与过去一个世纪的格陵兰局地温度存在显著相关性（相关系数r=0.471），同时也与诸多其他记录存在关联——包括特定站点的温压数据，以及温度跷跷板、北大西洋涛动这类温压环流型。针对北大西洋区域多组气象与气候参数与该堆叠同位素记录开展的多元线性回归（multiple linear regression）分析显示，共有5个变量对同位素记录的方差贡献显著：冬季北大西洋涛动、以太阳黑子数表征的太阳辐照度、格陵兰沿岸平均温度、格陵兰冰盖顶端水汽源区（30°-20°N）的海表温度，以及雅各布港与奥斯陆间的年际温度跷跷板。上述变量组合后得到的相关系数达r=0.71，可解释该堆叠同位素记录约一半的方差。