Variations in ozone depletion potentials of very short‐lived substances with season and emission region

We present a new approach for calculating the fraction of very‐short lived substances (VSLS) emitted at the surface (and their degradation products) that reach the stratosphere ( β ) using the FLEXPART Lagrangian model. The values of β play a key role in determining the efficiency of these compounds for depleting stratospheric ozone, and are used to estimate ozone depletion potentials (ODPs) of several short‐lived compounds. Calculated β and ODPs of VSLSs show large regional and seasonal variability owing to the importance of convective transport. For instance, β and ODPs associated with emissions from the Indian subcontinent is an order of magnitude larger than that from Europe, mid‐latitude North America, or East Asia. The seasonal cycle of β is mainly driven by transport efficiency from the boundary layer into the tropical stratosphere; β has a minimum in winter and a maximum in summer.