Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 7 5 2007 10.5194/acpd-7-13989-2007 http://www.atmos-chem-phys-discuss.net/7/13989/2007/ http://www.atmos-chem-phys-discuss.net/7/13989/2007/acpd-7-13989-2007.html http://www.atmos-chem-phys-discuss.net/7/13989/2007/acpd-7-13989-2007.pdf 13989 14010 2007-09-28 Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter K. Krüger kkrueger@ifm-geomar.de S. Tegtmeier M. Rex IFM-GEOMAR, Kiel, Germany University of Toronto, Toronto, Canada Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. 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