Determination of volcanic aerosols from Aurora Basin North, an ice core from East Antarctica

Volcanic eruptions are important natural drivers of short term climate changes and knowledge of their effects will lead to a greater understanding of how the climate system works under future human induced changes. Defining small and moderate eruptions can be challenging and appears to be dependent on individual ice core site characteristics, leading to some confusion regarding their climatic impacts. In this study, ice core aerosol records from a new inland East Antarctica site, Aurora Basin North (ABN), were compared to other Antarctic sites using ternary plots to investigate the characteristics of sea salts. At ABN, the most dominant mode in the ternary plots was sulfate rich, sea salt deficient, indicating the site is heavily influenced on additional sources of sulfate with minimal influence of sea salts. In the period 1800-2000CE, a total of eight volcanic eruptions were identified, in agreement with other ice cores. Despite this, the dominance of sulfate lead to difficulty in separating small eruptions from the background sulfate and a weak seasonal cycle. The sulfate record at ABN provides for a useful volcanic ice core record, particularly for estimating the magnitude of the moderate and large eruptions. By using ternary plots and the ABN sulfate record, characteristics for a useful volcanic ice core record were identified. The ice core site should be where the seasonal sea salt record is maintained and the overall influence of sources other than volcanic sulfate is minimal.