Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 8 4 2008 10.5194/acp-8-813-2008 http://www.atmos-chem-phys.net/8/813/2008/ http://www.atmos-chem-phys.net/8/813/2008/acp-8-813-2008.html http://www.atmos-chem-phys.net/8/813/2008/acp-8-813-2008.pdf 813 823 2008-02-19 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 Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany now at: IFM-GEOMAR, Kiel, Germany now at: University of Toronto, Toronto, Canada 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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