A selection of new science articles from the past week of interest to the SPARC community (a SPARC Office choice).

Characterizing the Lifetime and Occurrence of Stratospheric-Tropospheric Exchange Events in the Rocky Mountain Region Using High Resolution Ozone Measurements. By J.T. Sullivan et al. in the Journal of Geophysical Research: Atmospheres.

Reassessment of MIPAS age of air trends and variability. By F.J. Haenel et al. in Atmospheric Chemistry and Physics.

A potential vorticity-based determination of the transport barrier in the Asian summer monsoon anticyclone. By F. Ploeger et al. in Atmospheric Chemistry and Physics.

Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons. By T. Verhoelst et al.in Atmospheric Measurement Techniques.

A Solar Irradiance Climate Data Record. By O. Coddington et al. in the Bulletin of the American Meteorological Society.

Discussion papers – open for comment

Vortex-wide chlorine activation by a mesoscale PSC event in the Arctic winter of 2009/10. By T. Wegner et al. in Atmospheric Chemistry and Physics Discussions.

Atmospheric changes caused by galactic cosmic rays over the period 1960–2010. By C.H. Jackman et al. in Atmospheric Chemistry and Physics Discussions.