As it is well known, the analysis of long-lived tracers are among the best tools to study transport in the stratosphere as given by the combination of wave-induced diabatic circulation and isentropic mixing. Appropriate diagnostics applied to tracer distributions can give a clearer and more complete picture of where, when and how transport occurs, than the simple analysis of tracer fields. Probability distribution functions (PDFs) of long-lived tracer concentrations measured from satellite, in particular, are suitable to identify regions in the stratosphere with different transport features and characterize the interface between tropical and extratropical air masses (so-called subtropical barrier). This methodology is applied to the long-lived tracer nitrous oxide (N2O) measured by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board ENVISAT, with the aim of showing how tracer PDFs appear and which kind of information on tracer distributions and stratospheric transport across the edge regions can be extracted from them. Sample applications to nitrous oxide observations from the Microwave Limb Sounder (MLS) instrument on board AURA and to methane observations from the HAlogen Occultation Experiment (HALOE) instrument on board UARS are also presented, with the aim of showing to which extent instruments with different spatial and temporal resolution, sampling characteristics, and measuring different species can reproduce mixing and barrier regions in the stratosphere, as diagnosed through the statistical analysis of long-lived tracer observations. The proposed diagnostics are designed to extract the maximum information not only from global satellite data, but also from Chemistry-Climate Model (CCM) data, encouraging comparisons and process-oriented validation of models. This research is performed at the Institute of Atmospheric Sciences and Climate (ISAC) of the Italian National Research Council (CNR), within the project DIMITRI (Diagnostics of Mixing and Transport in atmospheric Interfaces) as a part of the ESA Changing Earth Science Network initiative.

This event is part of the eventgroup Atmospheric trace gases and remote sensing

Speaker
Dr. Elisa Palazzi

Bologna, Italy
ISAC-CNR

Organizer
Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU)
Karlsruher Institut für Technologie (KIT)
Kreuzeckbahnstraße 19
82467 Garmisch-Partenkirchen
Mail: hape schmid ∂does-not-exist.imk kit edu