Intrusions of mid-latitude and stratospheric air into the troposphere of the tropical americas: Evidence from Ticosonde and EOS satellite remote sensing measurements

Ozonesonde profiles made in Costa Rica since July 2005 have from time to time included enhancements of concentration in distinct shallow layers; these have been observed in the troposphere and in the tropical tropopause layer (TTL). Here we show through trajectory analysis of two ascents on consecutive days in July 2005 that narrow layers of enhanced ozone, often termed laminations, may be intrusions of air from middle latitudes, and in this case probably due to extrusion of middle latitude air associated with Rossby wave-breaking processes in the summer hemisphere. Remote sensing measurements of ozone and water vapor from the MLS instrument on the NASA Aura satellite provide a large-scale and regional context for these observations as well as support the identification of origins identified in the trajectory analysis.