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Last 15K years DomeC

Notes:

The temperature spike in recent history is an anomaly in the data. It's a data point from 1900, where the next 2 data points (1910 and 1920) reverse most of the increase seen from 1890 to 1900. This increase is not otherwise recorded in the climate record, although around 1910 was unusually cold. The spike seems to be due to aliasing of seasonal or sunspot variability into seemingly longer term components.

There are no data points more recent than 1920, although there are 12 more recent ice core samples. These have either never been analyzed for deuterium, which is how temperature is estimated, or the results were inconclusive. This could be a consequence of the uncertainty in determining time scales and the differences between the 'Gas Age' and the 'Ice Age', which is a result of gases migrating through the ice cores and not necessarily aligning with deposited ice layers. Another complication is related to the aliasing of periodic variability, which would produce more unexpected deviations from the thermometer record.