A new model of cosmogenic production of radiocarbon C-14 in the atmosphere

作者：Kovaltsov Gennady A; Mishev Alexander; Usoskin Ilya G^*

来源：Earth and Planetary Science Letters, 2012, 337: 114-120.

DOI：10.1016/j.epsl.2012.05.036

• cosmic rays
• Earth%26apos
• s atmosphere
• cosmogenic isotopes
• radiocarbon C-14

We present the results of full new calculation of radiocarbon C-14 production in the Earth atmosphere, using a numerical Monte-Carlo model. We provide, for the first time, a tabulated C-14 yield function for the energy of primary cosmic ray particles ranging from 0.1 to 1000 GeV/nucleon. We have calculated the global production rate of C-14, which is 1.64 and 1.88 atoms/cm(2)/s for the modern time and for the pre-industrial epoch, respectively. This is close to the values obtained from the carbon cycle reservoir inventory. We argue that earlier models overestimated the global C-14 production rate because of outdated spectra of cosmic ray heavier nuclei. The mean contribution of solar energetic particles to the global C-14 is calculated as about 0.25% for the modern epoch. Our model provides a new tool to calculate the C-14 production in the Earth%26apos;s atmosphere, which can be applied, e.g., to reconstructions of solar activity in the past.

• 出版日期2012-7-1