Open AccessObservations of convective and dynamical instabilities in tropopause folds and their contribution to stratosphere‐troposphere exchange
Author(s) -
Cho John Y. N.,
Newell Reginald E.,
Bui T. Paul,
Browell Edward V.,
Fenn Marta A.,
Mahoney Michael J.,
Gregory Gerald L.,
Sachse Glen W.,
Vay Stephanie A.,
Kucsera Tom L.,
Thompson Anne M.
Publication year - 1999
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jd900430
Subject(s) - tropopause , troposphere , stratosphere , instability , convection , convective instability , atmospheric sciences , geophysics , geology , physics , mechanics
With aircraft‐mounted in situ and remote sensing instruments for dynamical, thermal, and chemical measurements we studied two cases of tropopause folding. In both folds we found Kelvin‐Helmholtz billows with horizontal wavelength of ∼900 m and thickness of ∼120 m. In one case the instability was effectively mixing the bottomside of the fold, leading to the transfer of stratospheric air into the troposphere. Also, we discovered in both cases small‐scale secondary ozone maxima shortly after the aircraft ascended past the topside of the fold that corresponded to regions of convective instability. We interpreted this phenomenon as convectively breaking gravity waves. Therefore we posit that convectively breaking gravity waves acting on tropopause folds must be added to the list of important irreversible mixing mechanisms leading to stratosphere‐troposphere exchange.