Speaker
Description
A new full model of the atmospheric transport of cosmogenic 10Be is presented which allows linking its production by cosmic rays with the measured concentrations in ice cores. The model is based on the focused SOCOL‐AERv2‐BE chemistry‐climate model coupled with the CRAC:10Be isotope production model. It includes all the relevant atmospheric processes and allows computing the isotope concentration in air at any given location and time for the given cosmic-ray flux. The model is validated with the measurements of 10Be in several polar ice cores located in Antarctica and Greenland for 1980–2007. The results imply that the model correctly reproduces the large‐scale atmospheric dynamics but does not accurately resolve synoptic‐scale variability. The dominant source of 10Be is found to be located in the middle stratosphere (25–40 km), in the tropical (<30° latitudes) and polar (>60°) regions, as produced by galactic cosmic rays and solar energetic particles, respectively. It is shown that the majority of 10Be produced in the atmosphere reaches the Earth's surface within one–two years. We also present a practical parameterization of the full‐model results that are easy to compute and offer an accuracy of 20% in polar regions. This practical approach can be applied to studies of solar and geomagnetic variability using cosmogenic isotopes.
