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.

In April 1815 the Tambora volcano in Indonesia erupted, bringing immediate devastation to Sumbawa and the neighbouring islands. The impacts of this eruption were felt around the world for many months. In Europe and North America 1816 became known as the "Year Without a Summer" and over 100’000 people died.

The Tambora event is fascinating because it demonstrates how closely the Earth and human systems are connected. While scientific interest evolves from many specific questions at various interfaces within this system, it is also the “big picture” that matters. The bicentenary of the Tambora eruption 2015 was an opportunity to review our current understanding of the numerous aspects as a SPARC-supported conference held in Bern, Switzerland, in April 2015. Now, for the bicentenary of the 1816 “Year Without a Summer”, the picture has become much clearer. A booklet was put together to synthesise our knowledge of the Tambora eruption and the “Year Without a Summer”. Find the booklet here.

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

Ground-based assessment of the bias and long-term stability of 14 limb and occultation ozone profile data records. By D. Hubert et al. in Atmospheric Measurement Techniques.

An Observationally Constrained Evaluation of the Oxidative Capacity in the Tropical Western Pacific Troposphere. By J.M. Nicely et al. in the Journal of Geophysical Research: Atmospheres.

Decadal climate prediction with a refined anomaly initialisation approach. By D. Volpi et al. in Climate Dynamics.

Sensitivity of volcanic aerosol dispersion to meteorological conditions: a Pinatubo case study. By A.C. Jones et al. in the Journal of Geophysical Research: Atmospheres.

Role of quasiresonant planetary wave dynamics in recent boreal spring-to-autumn extreme events. By V. Petroukhov et al. in the Proceedings of the National Academy of Sciences of the United States of America.

Future Aerosol Reductions and Widening of the Northern Tropical Belt. By R.J. Allen and O. Ajoku in the Journal of Geophysical Research: Atmospheres.

Zonal-mean circulation response to reduced air-sea momentum roughness. By I. Polichtchouk and T.G. Shepherd in the Quarterly Journal of the Royal Meteorological Society.

A two-dimensional Stockwell transform for gravity wave analysis of AIRS measurements. By N.P. Hindley et al. in Atmospheric Measurement Techniques.

Discussion papers – open for comment

Effect of volcanic aerosol on stratospheric NO₂ and N₂O₅ from 2002–2014 as measured by Odin-OSIRIS and Envisat-MIPAS. By C. Adams et al. in Atmospheric Chemistry and Physics Discussions.

Trends of tropical tropospheric ozone from twenty years of European satellite measurements and perspectives for Sentinel-5 Precursor. By K.-P. Heue et al. in Atmospheric Measurement Techniques Discussions.

First detection of ammonia (NH₃) in the Asian monsoon upper troposphere. By M. Höpfner et al. in Atmospheric Chemistry and Physics Discussions.

Global distribution of CO₂ in the Upper-Troposphere and Stratosphere. By M. Diallo et al. in Atmospheric Chemistry and Physics Discussions.

Atmospheric abundance and global emissions of perfluorocarbons CF₄, C₂F₆ and C₃F₈ since 1900 inferred from ice core, firn, air archive and in situ measurements. By C.M. Trudinger et al. in Atmospheric Chemistry and Physics Discussions.

Direct Inversion of Circulation and Mixing from Tracer Measurements: I. Method. By T. von Clarmann and U. Grabowski in Atmospheric Chemistry and Physics Discussions.

Recent divergences in stratospheric water vapor measurements by frost point hygrometers and the Aura Microwave Limb Sounder. By D.F. Hurst et al. in Atmospheric Measurement Techniques Discussions.

Altitude Registration of Limb-Scattered Radiation. By L. Moy et al. in Atmospheric Measurement Techniques Discussions.

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

Towards a chemical reanalysis in a coupled chemistry-climate model: An evaluation of MOPITT CO assimilation and its impact on tropospheric composition. By B. Gaubert et al. in the Journal of Geophysical Research: Atmospheres.

An intensified hydrological cycle in the simulation of geoengineering by cirrus cloud thinning using ice crystal fall speed changes. By L.S. Jackson et al. in the Journal of Geophysical Research: Atmospheres.

Convective Transport of Formaldehyde to the Upper Troposphere and Lower Stratosphere and Associated Scavenging in Thunderstorms over the Central United States during the 2012 DC3 Study. By A. Fried et al. in the Journal of Geophysical Research: Atmospheres.

Impact of major volcanic eruptions on stratospheric water vapour. By M. Löffler et al. in Atmospheric Chemistry and Physics.

Space-based detection of missing sulfur dioxide sources of global air pollution. By C.A. McLinden et al. in Nature Geoscience.

Distinct effects of anthropogenic aerosols on the East Asian summer monsoon between multi-decadal strong and weak monsoon stages. By X. Xie et al. in the Journal of Geophysical Research: Atmospheres.

Ubiquitous Influence of Waves on Tropical High Cirrus Cloud. By J.-E. Kim et al. in Geophysical Research Letters.

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

Spectral distribution of gravity wave momentum fluxes over the antarctic peninsula from concordiasi super-pressure balloon data. By R.L. Walterscheid et al. in the Journal of Geophysical Research Letters: Atmospheres.

Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon region. By Y. Gu et al. in Atmospheric Chemistry and Physics.

Representation of the tropical stratospheric zonal wind in global atmospheric reanalyses. By Y. Kawatani et al. in Atmospheric Chemistry and Physics.

Discussion papers – open for comment

A comparison of Loon balloon observations and stratospheric reanalyses products. By L.S. Friedrich et al. in Atmospheric Chemistry and Physics Discussions.

Impacts of heterogeneous uptake of dinitrogen pentoxide and chlorine activation on ozone and reactive nitrogen partitioning: Improvement and application of WRF-Chem model in southern China. By Q. Li et al. in Atmospheric Chemistry and Physics Discussions.

Submission period now open: 1 June – 31 July

The EGU encourages individual scientists, working groups or committees to submit proposals for EGU topical meetings, training schools and workshops, as well as applications for EGU sponsorship of external meetings. The next call for EGU co-sponsored meetings is now open and runs from 1 June – 31 July. For more details see: www.egu.eu/meetings/support-request.

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

Fast descent routes from within or near the stratosphere to the surface at Fukuoka, Japan, studied using ⁷Be measurements and trajectory calculations. By H. Ito and Y. Narazaki in Atmospheric Chemistry and Physics.

Limitations of ozone data assimilation with adjustment of NO_x emissions: mixed effects on NO₂ forecasts over Beijing and surrounding areas. By X. Tang et al. in Atmospheric Chemistry and Physics.

The non-Gaussianity and spatial asymmetry of temperature extremes relative to the storm track: the role of horizontal advection. By C.I. Garfinkel and N. Harnik in the Journal of Climate.

Applications close Friday 27 May

Each year, JPL’s Center for Climate Sciences (CCS), along with co-sponsors, the Keck Institute for Space Studies (KISS) at Caltech and NASA’s Earth Science Division, brings together the next generation of climate scientists to engage with premier climate scientists from NASA, universities and other agencies. Applications are now being accepted from science and engineering graduate students and postdocs to fill approximately 24 slots for the 2016 event. You can find information about the school, as well as a link to apply at: http://climatesciences.jpl.nasa.gov/events/summer-school/about. All student travel, accommodation, and per diem expenses will be paid.

This annual event focuses on "Using Satellite Observations to Advance Climate Models". Students will explore how satellite observations can be used to evaluate and improve climate models, and will hear from a range of speakers on climate model diagnostics and evaluation in remote sensing of the planet.

Program Topics include:

• Global Climate Models
• Satellite Remote Sensing
• Climate Model Diagnostics and Evaluation

Most participants will be graduate students or postdoctoral researchers that are actively engaged in climate modelling, using satellite observations of Earth, or researching the physical climate system. However, we will also consider applications from Master’s degree students working in this area.

The SPARC Annual Report 2015 summarises the project’s activities of the past year as well as plans for the upcoming months. You can download it here.

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

Inter-comparison of stratospheric mean-meridional circulation and eddy mixing among six reanalysis data sets. By K. Miyazaki et al. in Atmospheric Chemistry and Physics.

ML-CIRRUS – The airborne experiment on natural cirrus and contrail cirrus with the high-altitude long-range research aircraft HALO. By C. Voigt et al. in the Bulletin of the American Meteorological Society.

Response of lightning NO_x emissions and ozone production to climate change: Insights from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). By D.L. Finney et al. in Geophysical Research Letters.

Climate change reduces warming potential of nitrous oxide by an enhanced Brewer-Dobson circulation. By D. Kracher et al. in Geophysical Research Letters.

Ozone variability in the troposphere and the stratosphere from the first 6 years of IASI observations (2008-2013). By C. Wespes et al. in Atmospheric Chemistry and Physics.

Evaluation of UTLS carbon monoxide simulations in GMI and GEOS-Chem chemical transport models using Aura MLS observations. By L. Huang et al. in Atmospheric Chemistry and Physics.

Climatology and ENSO-related interannual variability of gravity waves in the southern hemisphere subtropical stratosphere revealed by high-resolution AIRS observations. By K. Sato et al. in the Journal of Geophysical Research.

Midlatitude cloud shifts, their primary link to the Hadley cell, and their diverse radiative effects. By G. Tselioudis et al. in Geophysical Research Letters.

An idealized stratospheric model useful for understanding differences between long-lived trace gas measurements and global chemistry-climate model output. By E.A. Ray et al. in the Journal of Geophysical Research.

Reduction of climate sensitivity to solar forcing due to stratospheric ozone feedback. By G. Chiodo and L.M. Polvani in the Journal of Climate.

Transport vs. energetic particle precipitation: Northern polar stratospheric NO_x and ozone in January-March 2012. By S.-M. Päivärinta et al. in the Journal of Geophysical Research.

Kinematic and diabatic vertical velocity climatologies from a chemistry climate model. By A.M. Hoppe et al. in Atmospheric Chemistry and Physics.

Stratospheric age of air variations between 1600-2100. By S. Muthers et al. in Geophysical Research Letters.

The airborne mass spectrometer AIMS – Part 2: Measurements of trace gases with stratospheric or tropospheric origin in the UTLS. By T. Jurkat et al. in Atmospheric Measurement Techniques.

Discussion papers – open for comment

Projection of North Atlantic Oscillation and its effect on tracer transport. By S. Bacer et al. in Atmospheric Chemistry and Physics Discussions.

A laser-induced fluorescence instrument for aircraft measurements of sulfur dioxide in the upper troposphere and lower stratosphere. By A.W. Rollins et al. in Atmospheric Measurement Techniques Discussions.

The Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) database: A long-term database for climate studies. By S.M. Davis et al. in Earth System Science Data Discussions.

Advancements, measurement uncertainties, and recent comparisons of the NOAA frostpoint hygrometer. By E.G. Hall et al. in Atmospheric Measurement Techniques Discussions.

Validation of ACE-FTS version 3.5 NO_y species profiles using correlative satellite measurements. By P.E. Sheese et al. in Atmospheric Measurement Techniques Discussions.

Changes in the Width of the Tropical Belt due to Simple Radiative Forcing Changes in the GeoMIP Simulations. By N. Davis et al. in Atmospheric Chemistry and Physics Discussions.

Model – TCCON comparisons of column-averaged methane with a focus on the stratosphere. By A. Ostler et al. in Atmospheric Measurement Techniques Discussions.

Seasonal Variability of Stratospheric Methane: Implications for Constraining Tropospheric Methane Budgets Using Total Column Observations. By K.M. Saad et al. in Atmospheric Chemistry and Physics Discussions.

Stratospheric gravity waves at southern hemisphere orographic hotspots: 2003-2014 AIRS/Aqua observations. By L. Hoffmann et al. in Atmospheric Chemistry and Physics Discussions.

Role of vertical and horizontal mixing in the tape recorder signal near the tropical tropopause. By A.A. Granville and T. Birner in Atmospheric Chemistry and Physics Discussions.

Case Studies of the Impact of Orbital Sampling on Stratospheric Trend Detection and Derivation of Tropical Vertical Velocities: Solar Occultation versus Limb Emission Sounding. By L.F. Millán et al. in Atmospheric Chemistry and Physics Discussions.

A comparison of very short-lived halocarbon (VSLS) and DMS aircraft measurements in the Tropical West Pacific from CAST, ATTREX and CONTRAST. By S.J. Andrews et al. in Atmospheric Measurement Techniques Discussions.

Phosgene in the UTLS: seasonal and latitudinal variations from MIPAS observations. By M. Valeri et al. in Atmospheric Measurement Techniques Discussions.

The call for nominations to CLIVAR Scientific Steering Group (SSG) and CLIVAR panels is now open. The call for nominations to CLIVAR panels and groups is now open. Deadline for nominations for appointments starting in 2017 (and 2018 for the SSG) is 20 July 2016, and nominations can be submitted online here.