Mean residence time in the stratosphere

Abstract

The dataset contains model derived stratospheric residence times. Residence time is determined from idealized tracers with the EMAC model (Jöckel et al. 2016). These tracers are released at 480 points distributed across 20~latitudes in both hemispheres (mirrored around the equator) and 24~altitudes from the surface to the stratopause. While these tracers do not affect chemistry, radiation, or dynamics in the model and vice versa, cloud loss processes are applied at each time step. Hence, the tracers can be seen as idealized water vapor tracers. Employing this "soft" sink around the tropopause and in the troposphere allows tracer loss to follow the tropopause transition layer instead of a "rigid" tropopause definition. In an equilibrium of tracer emission to tracer loss, their ratio then gives residence time values on a multi-year mean basis.