Ice Cores

Because ice cores clearly show different layers of ice, dust, volcanic ash, etc, years and seasons are clearly distinguishable. This means that scientists can zero in on different years fairly easily and analyze what was happening during that time. Ice cores reveal atmospheric circulation patterns, because they show dust, volcanic ash, salts, etc. This means that scientists can analyze what they find in the ice cores in order to see what was happening but also why. They are able to determine wind strengths and pressure centers from the concentration of dust, ash, salt, etc. Ice cores also hold information about carbon dioxide concentrations. From the concentration of carbon dioxide in a particular part of the ice core, scientists can determine if that part of the Earth was experiencing a glacial or interglacial period because lower concentrations correlate with colder temperatures and visa versa.

Figure 1: Ice Core Data

Image Source: http://joannenova.com.au/globalwarming/graphs/ice-cores/vostok-ice-core-petit-web.gif

This figure shows the relationship between carbon dioxide concentrations found in ice cores in Antarctica as well as the temperatures. Seeing this correlation, scientists can now further relate lower concentrations with colder temperatures and high concentrations of carbon dioxide with high temperatures.