Premium
Is the residual vertical velocity a good proxy for stratosphere‐troposphere exchange of ozone?
Author(s) -
Hsu Juno,
Prather Michael J.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl061994
Subject(s) - stratosphere , tropopause , troposphere , atmospheric sciences , environmental science , climatology , ozone , residual , forcing (mathematics) , flux (metallurgy) , proxy (statistics) , ozone layer , meteorology , geology , chemistry , physics , algorithm , organic chemistry , machine learning , computer science
Stratosphere‐troposphere exchange (STE) of ozone (O 3 ) is key in the budget of tropospheric O 3 , in turn affecting climate forcing and global air quality. We compare three commonly used diagnostics meant to quantify cross‐tropopause O 3 fluxes with a Chemistry‐Transport Model driven by two distinct European Centre forecast fields. Our reference case calculates accurate, geographically resolved net transport across an isosurface in artificial tracer e90 representing the tropopause. Hemispheric fluxes derived from the ozone mass budget of the lowermost stratosphere yield similar results. Use of the Brewer‐Dobson residual vertical velocity as a scaled proxy for ozone flux, however, fails to capture the interannual variability. Thus, the common notion that the strength of stratospheric overturning circulation is a good measure for global STE does not apply to O 3 . Climatic variability in the modeled O 3 flux needs to be diagnosed directly rather than indirectly through the overturning circulation.