How unusual is today's solar activity? (reply)

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Muscheler et al.1 claim that the solar activity affecting cosmic rays was much higher in the past than we deduced2 from 14C measurements. However, this claim is based on a problematic normalization and is in conflict with independent results, such as the 44Ti activity in meteorites and the 10Be concentration in ice cores.

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Correspondence to S. K. Solanki.

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Solanki, S., Usoskin, I., Kromer, B. et al. How unusual is today's solar activity? (reply). Nature 436, E4–E5 (2005) doi:10.1038/nature04046

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