SPARC leadership is composed of experts from around the world who dedicate their time to SPARC’s international activities. These include the SPARC Scientific Steering Group (SSG), who serve to guide SPARC’s scientific focus. SPARC is now accepting nominations (or self-nominations) for SSG membership to serve from January 2018 – December 2020 (initial three-year term can be extended by two additional years). If you are interested please complete the online form available here. The deadline for nominations is 30 September 2016.

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

Direct injection of water vapor into the stratosphere by volcanic eruptions. By C.E. Sioris et al. in Geophysical Research Letters.

Gravity-wave effects on tracer gases and stratospheric aerosol concentrations during the 2013 ChArMEx campaign. By F. Chane Ming et al. in Atmospheric Chemistry and Physics.

UV and infrared absorption spectra, atmospheric lifetimes, and ozone depletion and global warming potentials for CCl₂FCCl₂F (CFC-112), CCl₃CClF₂ (CFC-112a), CCl₃CF₃ (CFC-113a), and CCl₂FCF₃ (CFC-114a). By M.E. Davis et al. in Atmospheric Chemistry and Physics.

Regional and Seasonal Stratospheric Temperature Trends in the Last Decade (2002-2014) from AMSU observations. By B.M. Funatsu et al. in the Journal of Geophysical Research: Atmospheres.

The STRatospheric Estimation Algorithm from Mainz (STREAM): estimating stratospheric NO2from nadir-viewing satellites by weighted convolution. By S. Beirie et al. in Atmospheric Measurement Techniques.

North Atlantic summer storm tracks over Europe dominated by internal variability over the past millennium. By M.H. Gagen et al. in Nature Geoscience.

The millennium water vapour drop in chemistry–climate model simulations. By S. Brinkop et al. in Atmospheric Chemistry and Physics.

Quantifying Eddy Feedbacks and Forcings in the Tropospheric Response to Stratospheric Sudden Warmings. By P. Hitchcock and I.R. Simpson in the Journal of Atmospheric Sciences.

Impact of Aerosols on Precipitation from Deep Convective Clouds in Eastern China. By M. Jiang et al. in the Journal of Geophysical Research: Atmospheres.

Hybrid ensemble 4DVar assimilation of stratospheric ozone using a global shallow water model. By D.R. Allen et al. in Atmospheric Chemistry and Physics.

Discussion papers – open for comment

Time varying changes in the simulated structure of the Brewer Dobson Circulation. By C.I. Garfinkel et al. in Atmospheric Chemistry and Physics Discussions.

Derivation of Antarctic stratospheric sulfuric acid profiles and nucleation modeling of the polar stratospheric CN layer. By S. Münch and J. Curtius in Atmospheric Chemistry and Physics Discussions.

The role of methane in projections of 21st century stratospheric water vapour. By L. Revell et al. in Atmospheric Chemistry and Physics Discussions.

A workshop on "The Future of Cumulus Parametrisation" will be held from 10-14 July 2017 in Delft, the Netherlands. Please save the date!

Registration will close on 15 May 2017.

Find website.

The Intergovernmental Panel on Climate Change (IPCC) is seeking responses to a questionnaire that will inform a special report on the impacts of a 1.5°C increase in global temperature. The Steering Committee for the Special Report on 1.5ºC has prepared this questionnaire ahead of the Scoping Meeting to be held in August 2016, with the intent to help form the structure and contents of the report.

The questionnaire is available here: https://www.ipcc.ch/report/sr15/pdf/sr15_prescoping_questionnaire.pdf

If you wish to contribute, please return the questionnaire to: tsu@ipcc-wg1.universite-paris-saclay.fr by 15 July 2016.

For further information you can visit the IPCC webpage: https://www.ipcc.ch/report/sr15/ or consult the Future Earth website: http://futureearth.org/news/complete-questionnaire-upcoming-ipcc-report-15degc-climate-target

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

Impact of geographic variations of the convective and dehydration center on stratospheric water vapor over the Asian monsoon region. By K. Zhang et al. in Atmospheric Chemistry and Physics.

Reconciling the Observed and Modeled Southern Hemisphere Circulation Response to Volcanic Eruptions. By M.C. McGraw et al. in Geophysical Research Letters.

The response of high-impact blocking weather systems to climate change. By D. Kennedy et al. in Geophysical Research Letters.

Emergence of healing in the Antarctic ozone layer. By S. Solomon et al. in Science.

Persistence of upper stratospheric wintertime tracer variability into the Arctic spring and summer. By D.E. Siskind et al. in Atmospheric Chemistry and Physics.

Discussion papers – open for comment

Multi-model dynamic climate emulator for solar geoengineering. By D.G. MacMartin and B. Kravitz in Atmospheric Chemistry and Physics Discussions.

Multidecadal Variations of the Effects of the Quasi-Biennial Oscillation on the Climate System. By S. Brönnimann et al. in Atmospheric Chemistry and Physics Discussions.

Decadal changes in global surface NO_x emissions from multi-constituent satellite data assimilation. By K. Miyazaki et al. in Atmospheric Chemistry and Physics Discussions.

The Nonequilbrium Thermodynamics of Atmospheric Blocking. By A. Jensen in Atmospheric Chemistry and Physics Discussions.

A long term study of polar ozone loss derived from data assimilation of Odin/SMR observations. By K. Sagi and D. Murtagh in Atmospheric Chemistry and Physics Discussions.

A side meeting on "Ozone Profile Trend Uncertainty" is planned following the Quadrennial ozone symposium. The meeting aims to address the fundamental question of whether the positive trend of ozone in the post-2000 period is statistically significant or not. Among topics for discussion are uncertainties of ozone trend estimates, statistical tools, comparison between observation and model trend estimates, and next steps for the upcoming WMO ozone assessment of 2018. This meeting is a follow up of the 2011-2014 SPARC/IO3C/IGACO initiative (SI2N).

9 September 2016, 16:00-18:00 and 10 September 2016, 9:00 – 12:00

The University of Edinburgh Outreach Centre, Holyrood Road, Edinburgh, EH8 8AQ

Organisers: Irina Petropavlovskikh, Sophie Godin- Beekmann, Elizabeth Weatherhead, Richard Stolarski, Paul Newman, and Neil Harris.

Proposed presentations:

1. Serge Gullias (UCL) – Presentation of results published by Ah Yeon (ACP) and Kai-Lan (AMT), with emphasis on uncertainties in statistical analysis of data for trends (a functional principal component analysis and stochastic partial differential equation (SPDE) approach with the covariance-based kriging).
2. Jos Laat de (KNMI) – Presentation from the perspective of ozone depletion in the Antarctic Ozone Hole.
3. René Stübi (MeteoSwiss) – Report on the updated trend from Payerne soundings and comparison with those evaluated from the ESA CCI-Ozone satellites records. The problem of “too” short time series to accurately determine the proxies could be also discussed as well as the fact that some proxies have themselves an underlying trend.
4. Roeland Van Malderen (Royal Meteorological Institute of Belgium (RMI), Belgium) – Correction strategies of ozonesonde data and their impact on (simple linear) trends (with 2-sigma uncertainties), and how sampling frequency (once a week vs 3 times a week) affects these trends (by comparing Uccle and De Bilt datasets).
5. Johanna Tamminen (Finnish Meteorological Institute) – Statistical significance of estimated trends in stratospheric ozone profiles.
6. Herman Smit (Research Centre Jülich, Germany) – Uncertainty of ozonesondes, particularly from the most recent ozonesonde-homogenization efforts.
7. Thomas von Clarmann (IMK, KIT) – Desiderata for a community analysis tool, summary of is available from IMK, problems encountered, ongoing activities on uncertainty assessment (particularly of satellite data), etc.
8. Victoria Sofieva (FMI) – ESA Ozone_CCI experience of satellite limb ozone profiles merging and uncertainty characterization.
9. Robert Domadeo (LARC, NASA) – Limitations of the multiple linear regression tool commonly used for trend analysis and how things like diurnal variability, drifts, and sampling patterns fundamentally limit what datasets can be used for these analyses.
10. Daan Hubert (Royal Belgian Institute for Space Aeronomy, Belgium) – The Monte Carlo approach to estimating ozone trend uncertainties.

If you are interested in participating, please contact Irina Petropavlovskikh: irina.petro@noaa.gov

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

Missing orographic drag leads to climate model biases in jet streams, blocking and storm tracks. By F. Pithan et al. in Geophysical Research Letters.

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

MJO-related intraseasonal variation of gravity waves in the southern hemisphere tropical stratosphere revealed by high-resolution airs observations. By C. Tsuchiya et al. in the Journal of Geophysical Research: Atmospheres.

Diverse policy implications for future ozone and surface UV in a changing climate. By A.H. Butler et al. in Environmental Research Letters.

Strong modification of stratospheric ozone forcing by cloud and sea-ice adjustments. By Y. Xia et al. in Atmospheric Chemistry and Physics.

The Sub-seasonal to Seasonal Prediction (S2S) Project Database. By F. Vitart et al in the Bulletin of the American Meteorological Society.

Tracking the delayed response of the northern winter stratosphere to ENSO using multi reanalyses and model simulations. By R. Ren et al. in Climate Dynamics.

Understanding the links between subtropical and extratropical circulation responses to climate change using aquaplanet model simulations. By T. Shaw and A. Voigt in the Journal of Climate.

Discussion papers – open for comment

Lidar studies on microphysical influences on the structure and lifetime of tropical cirrus clouds. By G.S. Motty et al. in Atmospheric Chemistry and Physics Discussions.

Long-range transport pathways of tropospheric source gases originating in Asia into the northern lower stratosphere during the Asian monsoon season 2012. By B. Vogel et al. in Atmospheric Chemistry and Physics Discussions.

A large number of SPARC-related sessions have been organised for this year’s fall AGU meeting (abstract submission deadline 1 August 2018). The following is a non-exhaustive list:

A016: Atmospheric Trace Species: Budget and transport of stratospheric-ozone-related and climate-related trace gases

Convenors: Paul A. Newman, Qing Liang, Guus J M Velders, and Stefan Reimann

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session12535

A017: Atmospheric Trace Species: Observations and Analyses of the Effects of Changing Atmospheric Composition on Stratospheric Ozone and Climate

Convenors: Michael J. Kurylo III, Anne M. Thompson, Joris P. Veefkind, and Martyn Chipperfield.

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session12533

A064: Large-scale atmospheric transport and mixing: observations, modeling and theory

Conveners: Chengji Liu, Elizabeth A Barnes, Clara Orbe, Gang Chen

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session12755

SA005: Atmospheric gravity wave sources, propagation, instabilities, and regional and global effects from the surface into the thermosphere and ionosphere

Conveners: David C. Fritts, Michael J. Taylor, Kaoru Sato, Erdal Yigit

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session13072

A086: Processes and linkages in the upper troposphere and lower stratosphere: observations and models

Conveners: Rei Ueyama, William John Randel, Tao Wang

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session12421

A099: The dynamical processes of stratosphere-troposphere interactions and their relationship with climate

Conveners: Marianna Linz, Aditi Sheshadri, Alison Ming, Peter Hitchcock

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session13040

A003: Advances in High Resolution Climate Modeling in the atmosphere

Conveners: Philip J Rasch, Shaocheng Xie, Julio T Bacmeister, Jon Petch

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session13113

A049: Evaluating Reanalysis: Learning about past weather and climate

Conveners: Jan Dominik Keller, Masatomo Fujiwara, Sean M. Davis

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session13068

A037: Data Assimilation, Inverse Methods, Reanalysis, and Observing System Simulation Experiments

Conveners: Isaac Moradi, Thomas Auligne, Nancy L. Baker, Zhaoxia Pu

https://agu.confex.com/agu/fm16/preliminaryview.cgi/Session13673

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.