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

Upper tropospheric water vapour variability at high latitudes – Part 1: Influence of the annular modes. By C.E. Sioris et al. in Atmospheric Chemistry and Physics.

A new class of vacillations of the stratospheric polar vortex. By R.K. Scott in the Quarterly Journal of the Royal Meteorological Society.

The atmospheric partial lifetime of carbon tetrachloride with respect to the global soil sink. By R. Rhew and J. Happell in Geophysical Research Letters.

Long-term validation of ESA operational retrieval (version 6.0) of MIPAS Envisat vertical profiles of methane, nitrous oxide, CFC11, and CFC12 using balloon-borne observations and trajectory matching. By A. Engel et al. in Atmospheric Measurement Techniques.

Satellite-based global volcanic SO₂ emissions and sulfate direct radiative forcing during 2005-2012. By C. Ge et al. in the Journal of Geophysical Research: Atmospheres.

An assessment of the consistency between satellite measurements of upper tropospheric water vapor. By E.-S. Chung et al. in the Journal of Geophysical Research: Atmospheres.

Polar stratospheric cloud evolution and chlorine activation measured by CALIPSO and MLS, and modeled by ATLAS. By H. Nakajima et al. in Atmospheric Chemistry and Physics.

Global HCFC-22 measurements with MIPAS: retrieval, validation, global distribution and its evolution over 2005–2012. By M. Chirkov et al. in Atmospheric Chemistry and Physics.

Convective sources of trajectories traversing the tropical tropopause layer. By A.-S. Tissier and B. Legras in Atmospheric Chemistry and Physics.

Atmospheric histories and global emissions of halons H-1211 (CBrClF₂), H-1301 (CBrF₃), and H-2402 (CBrF₂CBrF₂). By M.K. Vollmer et al. in the Journal of Geophysical Research: Atmospheres.

Trapping, chemistry, and export of trace gases in the South Asian summer monsoon observed during CARIBIC flights in 2008. By A. Rauthe-Schöch et al. in Atmospheric Chemistry and Physics.

Variational data assimilation for the optimized ozone initial state and the short-time forecasting. By S.-Y. Park et al. in Atmospheric Chemistry and Physics.

Discussion papers – open for comment

Results from the validation campaign of the ozone radiometer GROMOS-C at the NDACC station of La Réunion Island. By S. Fernandez et al. in Atmospheric Chemistry and Physics Discussions.

30 years of upper air soundings on board of R/V POLARSTERN. By A. Driemel et al. in Earth System Science Data Discussions.

Spectral analysis of atmospheric composition: application to surface ozone model-measurement comparisons. By D.R. Bowdalo et al. in Atmospheric Chemistry and Physics Discussions.

The Tropical Tropopause Inversion Layer. By R.P. Kedzierski et al. in Atmospheric Chemistry and Physics Discussions.

AerGOM, an improved algorithm for stratospheric aerosol retrieval from GOMOS observations. Part 2: Intercomparisons. By C.E. Robert et al. in Atmospheric Measurement Techniques Discussions.

The natural oscillations in stratospheric ozone observed by the GROMOS microwave radiometer at the NDACC station Bern. By L. Moreira et al. in Atmospheric Chemistry and Physics Discussions.

Evaluation of Water Vapour Assimilation in the Tropical Upper Troposphere and Lower Stratosphere by a Chemical Transport Model. By S. Payra et al. in Atmospheric Measurement Techniques Discussions.