Comparison of accumulation rates and stable isotope ratios

The high spatial and interannual variability, however, means that trends must be interpreted with care. In spite of the highly irregular accumulation distribution, stable-isotope ratios show little spatial variability. The mean annual d18O values of cores B04 and FB0198 agree fairly well for the time period 1955-82 covered by both cores. d18O values have increased during most of the 20th century; since the late 1980s a decrease is observed.

This change is not related to air temperature, since mean annual air temperatures at Neumayer show no significant trend over the last two decades.