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:

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.

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.