Comments welcome until 25 September

A panel of experts has created an updated draft position of the American Geophysical Union (AGU) on geoengineering. AGU first formulated an official position on geoengineering in 2009, when it adopted a statement in collaboration with the American Meteorological Society. AGU last updated its geoengineering statement in 2012. The organization encourages its members to provide written feedback about this draft statement during a 30-day comment period that opens today and closes on Monday, 25 September at 11:59 p.m. Eastern time. Find more information on their website: https://eos.org/agu-news/position-statement-on-geoengineering-call-for-comments.

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

Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere. By J.W. Greenside et al. in Atmospheric Chemistry and Physics.

The version 3 OMI NO₂ standard product. By N.A. Krotkov et al. in Atmospheric Measurement Techniques.

Lightning NOx Emissions: Reconciling measured and modeled estimates with updated NOx chemistry. By B.A. Nault et al. in Geophysical Research Letters.

Stratospheric intrusion-influenced ozone air quality exceedences investigated in the NASA MERRA-2 Reanalysis. By K.E. Knowland et al. in Geophysical Research Letters.

Does the lower stratosphere provide predictability for month-ahead wind electricity generation in Europe? By R. Beerli et al. in the Quarterly Journal of the Royal Meteorological Society.

Discussion papers – open for comment

Characterizing Sampling and Quality Screening Biases in Infrared and Microwave Limb Sounding. By L.F. Millan et al. in Atmospheric Chemistry and Physics Discussions.

View SPARC eNews September 2017.

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

Large wind shears and their implications for diffusion in regions with enhanced static stability: the mesopause and the tropopause. By H.-L. Liu in the Journal of Geophysical Research: Atmospheres.

The strength of the meridional overturning circulation of the stratosphere. By M. Linz et al. in Nature Geoscience.

CCl₄ distribution derived from MIPAS ESA v7 data: intercomparisons, trend, and lifetime estimation. By M. Valeri et al. in Atmospheric Chemistry and Physics.

Intercomparison of NOx emission inventories over East Asia. By J. Ding et al. in Atmospheric Chemistry and Physics.

Small-scale wind fluctuations in the tropical tropopause layer from aircraft measurements: occurrence, nature and impact on vertical mixing. By A. Podglajen et al. in the Journal of the Atmospheric Sciences.

Variability of Stratospheric Reactive Nitrogen and Ozone Related to the QBO. By M. Park et al. in the Journal of Geophysical Research: Atmospheres.

Discussion papers – open for comment

Characterization and Correction of OMPS Nadir Mapper Measurements for Ozone Profile Retrievals. By J. Bak et al. in Atmospheric Measurement Techniques Discussions.

Tomographic retrievals of ozone with the OMPS Limb Profiler: algorithm description and preliminary results. By D.J. Zawada et al. in Atmospheric Measurement Techniques Discussions.

The Arosa site is well known in the ozone community for its continuous total ozone column observations recorded since 1926. Originally based on Dobson sun spectrophotometers, the site has been gradually complemented by three automatic Brewer instruments, in operation since 1998. To secure the long term ozone monitoring in this Alpine region and to benefit from synergies with the World Radiation Center, the feasibility of moving this activity to the nearby site at Davos (aerial distance of 13 km) has been explored. Join the discussion on the paper by Stuebi et al. published in Atmospheric Measurement Techniques.

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

A Case Study of Convectively Sourced Water Vapor Observed in the Overworld Stratosphere over the United States. By J.B. Smith et al. in the Journal of Geophysical Research: Atmospheres.

On the spatio-temporal representativeness of observations. By N. Schutgens et al. in Atmospheric Chemistry and Physics.

Modeling the inorganic bromine partitioning in the tropical tropopause layer over the eastern and western Pacific Ocean. By M.A. Navarro et al. in Atmospheric Chemistry and Physics.

Sensitivity of the tropical stratospheric ozone response to the solar rotational cycle in observations and chemistry–climate model simulations. By R. Thiéblemont et al. in Atmospheric Chemistry and Physics.

Processes maintaining tropopause sharpness in numerical models. By L. Saffin et al. in the Journal of Geophysical Research: Atmospheres.

Downward Influence of QBO-like Oscillation on Moist Convection in a Two-Dimensional Minimal Model Framework. By H.H. Bui et al. in the Journal of the Atmospheric Sciences.

Discussion papers – open for comment

Multi-model comparison of the volcanic sulfate deposition from the 1815 eruption of Mt. Tambora. By L. Marshall et al. in Atmospheric Chemistry and Physics Discussions.

On the distortions in calculated GW parameters during slanted atmospheric soundings. By A. de la Torre et al. in Atmospheric Measurement Techniques Discussions.

Retrieval of ozone profiles from OMPS limb scattering observations. By C. Arosio et al. in Atmospheric Measurement Techniques Discussions.

Chemical and climatic drivers of radiative forcing due to changes in stratospheric and tropospheric ozone over the 21st century. By A. Banerjee et al. in Atmospheric Chemistry and Physics Discussions.

The SPARC Office is in the transition of moving from ETH Zurich to the German Aerospace Center (DLR) in Oberpfaffenhofen. Apply for the position of Project Scientist in the new SPARC Office before 15 September.

Find vacancy.

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

Impact of Volcanic Aerosols on Stratospheric Ozone Recovery. By V. Naik et al. in the Journal of Geophysical Research: Atmospheres.

The characteristics of the lower stratospheric gravity wave field above Halley (75°S, 26°W), Antarctica, from radiosonde observations. By T. Moffat-Griffin and S.-R. Colwell in the Journal of Geophysical Research: Atmospheres.

Mirrored Changes in Antarctic Ozone and Stratospheric Temperature in the late 20th versus early 21st Centuries. By S. Solomon et al. in the Journal of Geophysical Research: Atmospheres.

Gravity Wave Spectra in the Lower Stratosphere Diagnosed from Project Loon Balloon Trajectories. By M.R. Schoeberl et al. in the Journal of Geophysical Research: Atmospheres.

Dynamical Heating of the Arctic Atmosphere during the Springtime Transition. By X. Long and W.A. Robinson in the Journal of Climate.

Contributions of climate feedbacks to changes in atmospheric circulation. By P. Ceppi and T.G. Shepherd in the Journal of Climate.

Connecting Tropical Climate Change with Southern Ocean Heat Uptake. By Y.-T- Hwang et al. in Geophysical Research Letters.

The relationship between northern hemisphere winter blocking and tropical modes of variability. By G. Gollan and R.J. Greatbatch in the Journal of Climate.

Discussion papers – open for comment

The Network for the Detection of Atmospheric Composition Change (NDACC): History, status and perspectives. By M. de Mazière et al. in Atmospheric Chemistry and Physics Discussions.

VESPA-22: a ground-based microwave spectrometer for long-term measurements of Polar stratospheric water vapor. By G. Mevi et al. in Atmospheric Measurement Techniques Discussions.

Drift corrected Odin-OSIRIS ozone product: algorithm and updated stratospheric ozone trends. By A.E. Bourassa et al. in Atmospheric Measurement Techniques Discussions.

WCRP and the World Weather Research Programme are seeking nominations for the International Prize for Model Development, awarded annually for an outstanding contribution to weather and climate model development by an early- to mid-career researcher. Find information on IPMD 2017.

In addition, WCRP together with the Global Climate Observing System (GCOS) are seeking nominations for the International Data Prize 2017. The prize is awarded annually to an early- to mid-career researcher for his or her outstanding contribution to the Earth system science community. Find information on IDP 2017.

Nominations for both prizes close on 1 October 2017.

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

Observational evidence of the downstream impact on tropical rainfall from stratospheric Kelvin waves. By L. Zhang et al. in Climate Dynamics.

Assessment of NOAA NUCAPS Upper Air Temperature Profiles Using COSMIC GPS Radio Occultation and ARM Radiosondes. By M.L. Feltz et al. in the Journal of Geophysical Research: Atmospheres.

Assessment of COSMIC radio occultation and AIRS hyperspectral IR sounder temperature products in the stratosphere using observed radiances. By M.L. Feltz et al. in the Journal of Geophysical Research: Atmospheres.

Dynamics and Predictability of Downward Propagating Stratospheric Planetary Waves Observed in March 2007. By H. Mukougawa et al. in the Journal of the Atmospheric Sciences.

Discussion papers – open for comment

Sensitivity of the radiative forcing by stratospheric sulfur geoengineering to the amount and strategy of the SO₂ injection studied with the LMDZ-S3A model. By C. Kleinschmitt et al. in Atmospheric Chemistry and Physics Discussions.

Accuracy and precision of lower stratospheric polar reanalysis temperatures evaluated from A-train CALIOP and MLS, COSMIC GPS RO, and the equilibrium thermodynamics of supercooled ternary solutions and ice clouds. By A. Lambert and M.L. Santee in Atmospheric Chemistry and Physics Discussions.

Intercomparison of AIRS and HIRDLS stratospheric gravity wave observations. By C.I. Meyer et al. in Atmospheric Measurement Techniques Discussions.