Mean age-of-air in the stratosphere

Abstract

The dataset contains model derived mean age-of-air. Age-of-air is calculated in the EMAC model from a passive tracer with linearly increasing mixing ratio specified at the surface. To calculate age-of-air relative to the tropical tropopause, the average age at 10°N to 10°S at the tropopause is subtracted. The simulation analyzed here is branched from a free‐running hindcast run, ensuring that the tracer field is fully spun up at the start of the period considered (Jöckel et al. 2016, RC1SD-base-10). Dynamics are specified with Newtonian relaxation, i.e. nudging, up to 10 hPa with ERA Interim (Dee et al. 2011).