Methanesulphonic acid loss during ice-core storage: recommendations based on a new diffusion coefficient

The loss of methanesul phonic acid (MSA) from stored ice cores can be significant over typical storage times, with diffusion to the ice-core surface controlling the loss. Methods for minimizing this loss are discussed and it is shown how measurements can be corrected by calculating the amount of MSA lost. A revised diffusion coefficient for MSA in solid ice, (4.1 × 10−13) ± (2.5 × 10−14) m2 s−1, is derived to improve such MSA loss corrections.