English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

. The paper presents a comparative study of age of air (AoA) derived fromseveral approaches: a widely used passive-tracer accumulation method, the SF6 accumulation, and a direct calculation of an ideal-age tracer. Thesimulations were performed with the Eulerian chemistry transport modelSILAM driven with the ERA-Interim reanalysis for 1980–2018. The Eulerian environment allowed for simultaneous application of several approacheswithin the same simulation and interpretation of the obtained differences. A seriesof sensitivity simulations revealed the role of the vertical profile of turbulentdiffusion in the stratosphere, destruction of SF6 in the mesosphere, and the effect of gravitational separation of gases with strongly different molar masses. The simulations reproduced well the main features of the SF6 distribution in the atmosphere observed by the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) satellite instrument.It was shown that the apparent very old air in the upper stratosphere derived from the SF6 profile observations is a resultof destruction and gravitational separation of this gas in the upper stratosphereand the mesosphere. These processes make the apparent SF6 AoA in the stratosphere several years olderthan the ideal-age AoA, which, according to our calculations, does not exceed 6–6.5 years.The destruction of SF6 and the varying rate of emission make SF6 unsuitablefor reliably deriving AoA or its trends.However, observations of SF6 provide a very useful dataset for validation ofthe stratospheric circulation in a model with the properly implemented SF6 loss.

Simulating age of air and the distribution of SF&lt;sub&gt;6&lt;/sub&gt; in the stratosphere with the SILAM model

Simulating age of air and the distribution of SF<sub>6</sub> in the stratosphere with the SILAM model