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

High-frequency gravity waves and homogeneous ice nucleation in tropical tropopause layer cirrus. By E.J. Jensen et al. in Geophysical Research Letters.

High-resolution tropospheric carbon monoxide profiles retrieved from CrIS and TROPOMI. By D. Fu et al. in Atmospheric Measurement Techniques.

The Impact of GCM Dynamical Cores on Idealized Sudden Stratospheric Warmings and their QBO Interactions. By W. Jao and C. Jablonowski in the Journal of the Atmospheric Sciences.

Simulated 2050 aviation radiative forcing from contrails and aerosols. By C.-C. Chen and A. Gettelman in Atmospheric Chemistry and Physics.

Reversal of global atmospheric ethane and propane trends largely due to US oil and natural gas production. By D. Helmig et al. in Nature Geoscience.

Tuning of a convective gravity wave source scheme based on HIRDLS observations. By Q.T. Trinh et al. in Atmospheric Chemistry and Physics.

The linkage between stratospheric water vapor and surface temperature in an observation-constrained coupled general circulation model. By Y. Wang et al. in Climate Dynamics.

On the ambiguous nature of the 11-year solar cycle signal in upper stratospheric ozone. By S.S. Dhomse et al. in Geophysical Research Letters.

Classification of stratospheric extreme events according to their downward propagation to the troposphere. By T. Runde et al. in Geophysical Research Letters.

The impact of lightning on tropospheric ozone chemistry using a new global lightning parametrisation. By D.L. Finney et al. in Atmospheric Chemistry and Physics.

MiKlip – a National Research Project on Decadal Climate Prediction. By J. Marotzke et al. in the Bulletin of the American Meteorological Society.

New and improved infrared absorption cross sections for chlorodifluoromethane (HCFC-22). By J.J. Harrison in Atmospheric Measurement Techniques.

Discussion papers – open for comment

Interannual variations of early winter Antarctic polar stratospheric cloud formation and nitric acid observed by CALIOP and MLS. By A. Lambert et al. in Atmospheric Chemistry and Physics Discussions.

Intercomparison and evaluation of satellite peroxyacetyl nitrate observations in the upper troposphere – lower stratosphere. By R.J. Pope et al. in Atmospheric Chemistry and Physics Discussions.

Retrievals of heavy ozone with MIPAS. By B. Jonkheid et al. in Atmospheric Measurement Techniques Discussions.