IGAC’s Tropospheric Ozone Assessment Report (TOAR) is being published as a series of papers in the peer-reviewed, open-access journal, Elementa:  Science of the Anthropocene.  The papers are appearing in a Special Feature of Elementa as they are accepted for publication, with the latest paper, TOAR-Observations now available:

From the earliest observations of ozone in the lower atmosphere in the 19th century, both measurement methods and the portion of the globe observed have evolved and changed. In this study, various ozone measurement methods and ozone datasets are reviewed and selected for inclusion in the historical record of background ozone levels, based on relationship of the measurement technique to the modern UV absorption standard, absence of interfering pollutants, representativeness of the well-mixed boundary layer and expert judgement of their credibility.  We found no unambiguous evidence in the measurement record back to 1896 that typical mid-latitude background surface ozone values were below about 20 nmol mol^-1, but there is robust evidence for increases in the temperate and polar regions of the northern hemisphere of 30-70%, with large uncertainty, between the period of historic observations, 1896-1975, and the modern period (1990-2014).  Independent historical observations from balloons and aircraft indicate similar changes in the free troposphere. Changes in the southern hemisphere are much less. Regional representativeness of the available historical observations remains a potential source of large errors, which are difficult to quantify.

Tarasick*, D. W., I. E. Galbally*, O. R. Cooper, M. G. Schultz, G. Ancellet,  T. Leblanc, T. J. Wallington, J. Ziemke, X. Liu, M. Steinbacher, J. Staehelin, C. Vigouroux, J. W. Hannigan, O. García, G. Foret, P. Zanis, E. Weatherhead, I. Petropavlovskikh, H. Worden, M. Osman, J. Liu, K.-L. Chang, A. Gaudel, M. Lin, M. Granados-Muñoz, A. M. Thompson, S. J. Oltmans, J. Cuesta, G. Dufour, V. Thouret, B. Hassler, T. Trickl and J. L. Neu (2019), Tropospheric Ozone Assessment Report: Tropospheric ozone from 1877 to 2016, observed levels, trends and uncertainties. Elem Sci Anth, 7(1), DOI: http://doi.org/10.1525/elementa.376.

*coordinating lead authors

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

Stratospheric ozone trends for 1985–2018: sensitivity to recent large variability. By W.T. Ball et al. in Atmospheric Chemistry and Physics.

Multiscale extratropical barotropic variability on the subseasonal‐to‐seasonal timescale. By L. Boljka and T.G. Shepherd in the Quarterly Journal of the Royal Meteorological Society.

Diagnosing topographic forcing in an atmospheric dataset: the case of the North American Cordillera. By K. Hartung et al. in the Quarterly Journal of the Royal Meteorological Society.

Evidence of small-scale quasi-isentropic mixing in ridges of extratropical baroclinic waves. By D. Kunkel et al. in Atmospheric Chemistry and Physics.

The Buffer Zone of the Quasi-Biennial Oscillation. By A. Match and S. Fueglistaler in the Journal of the Atmospheric Sciences.

Unified quantitative observation of coexisting volcanic sulfur dioxide and sulfate aerosols using ground-based Fourier transform infrared spectroscopy. By P. Sellitto et al. in Atmospheric Measurement Techniques.

Discussion Papers – open for comment:

Diurnal cycle of clouds extending above the tropical tropopause observed by spaceborne lidar. By T. Dauhut, V. Noël, and I.-A. Dion in Atmospheric Chemistry and Physics.

Ice injected into the tropopause by deep convection – Part 2: Over the Maritime Continent. By I.-A. Dion et al. in Atmospheric Chemistry and Physics.

Simulation of convective moistening of extratropical lower stratosphere using a numerical weather prediction model. By Z. Qu et al. in Atmospheric Chemistry and Physics.

FESSTVaL (Field Experiment on submesoscale spatio-temporal variability in Lindenberg) is a measurement campaign initiated by the Hans-Ertel-Center for Weather Research. It will take place in the summer months of the year 2020 at the Meteorological Observatory Lindenberg – Richard-Aßmann-Observatorium (MOL-RAO) of the German Weather Service (DWD) near Berlin. During the intensive observation period in July 2020, a summer school is offered by the participating scientists of FESSTVaL, complemented by additional lecturers. As FESSTVaL is a joint project of about a dozen scientists from seven different institutions in Germany, most of them being junior scientists (PhD and Postdoc), the working environment is dynamic and expert knowledge is brought together.

For further information on the campaign, please visit http://fesstval.de

The summer school takes place from 13 to 24 July 2020 in Lindenberg (Mark), Brandenburg, Germany, close to Berlin. It is aimed to MSc and PhD students, and Postdocs in meteorology, physics and related research areas. The seminars, group projects and lectures during FESSTVaL Summer School
are offered by national and international experts. The 12 day long intensive program will provide participants with insights into observing and understanding submesoscale atmospheric dynamics, such as convective scale observations from different platforms, submesoscale dynamics and modeling. The deadline for submission of your application is 30 November 2019. More information and details about the submission can be found at http://fesstval.de/index.php?id=5132&L=2

Download call for applications

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REMINDER: Registration for the CATCH Open Science Workshop is open until
23:59 MDT 11 October 2019

If you wish to request travel support to the workshop, please register immediately and make sure to send your CV to .

CATCH Open Science Workshop

7-8 December 2019
Berkeley, CA
Register here

An important objective of this workshop is to gather ideas and community support to develop CATCH working groups in order to focus research on emerging CATCH topics and research challenges. Therefore, this is a working workshop and all participants will have an active participation role. We are not collecting abstracts, but rather titles of presentations that participants would like to give. Following registration we will put together an agenda with talks, posters, and discussion sessions. Participants will be notified of their presentation type a month prior to the meeting. You are also welcome to attend without giving a presentation and your input to the working workshop will be through the discussion sessions in addition to Q&A during the oral and poster presentations.

There is limited funding available for travel support. Please only apply for travel support if you absolutely need it. Priority for travel support will be for early career scientists (current graduate student or within 4 years of receiving a PhD, excluding career breaks) and scientists from scientifically emerging countries. If you wish to apply for travel support but absolutely cannot afford to pay the registration fee and be reimbursed, please send your CV and a brief paragraph about the research you conduct relevant to CATCH to Jennie Thomas at .

Registration Information:

Registration fee: $150.00
The registration fee includes lunches and coffee/tea breaks for two days, and a group dinner on 7 December.
More information: catchscience.org

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

When and where do ECMWF seasonal forecast systems exhibit anomalously low signal‐to‐noise ratio? By A.J. Charlton-Perez et al. in the Quarterly Journal of the Royal Meteorological Society.

Structural changes and variability of the ITCZ induced by radiation–cloud–convection–circulation interactions: inferences from the Goddard Multi-scale Modeling Framework (GMMF) experiments. By W.K.M. Lau et al. in Climate Dynamics.

Rare warming over Antarctica reveals power of stratospheric models. News article by Dyanni Lewis in Nature.

Improved Simulation of the QBO in E3SMv1. By J.H. Richter et al. In the Journal of Advances in Modeling Earth Systems.

Quantifying stochastic uncertainty in detection time of human-caused climate signals. By B.D. Santer et al. in the Proceedings of the National Academy of Sciences of the Unted States of America (PNAS).

Discussion papers – open for comment:

Improving the prediction of an atmospheric chemistry transport model using gradient boosted regression trees. By P.D. Ivatt and M.J. Evans in Atmospheric Chemistry and Physics.

Modelling the potential impacts of the recent, unexpected increase in CFC-11 emissions on total column ozone recovery. By J. Keeble et al. in Atmospheric Chemistry and Physics.

The SSP greenhouse gas concentrations and their extensions to 2500. By M. Meinhausen et al. in Geoscientific Model Development.

The next Atmospheric Tomography Mission (ATom) Science Team Meeting will be held Nov. 18-20, 2019, NCAR Center Green Campus, Boulder, CO.  All registered guests^± are cordially invited to attend. Abstracts for presentations or posters are welcome and encouraged.

Go to https://forms.gle/vJZ7UkDeyrpq7WGVA to register for the meeting. Due to limited space at Center Green registration for the meeting is mandatory. While registration slots will be prioritized for current ATom team members others outside the current ATom team, who submit 2-3 sentence ATom related abstracts with their registrations, will be considered for those available remaining slots.  The ATom Science Leadership will review and accept these abstracts from outside the ATom Science Team for presentation in the order they come in until the attendance limit is met.

ATom is a NASA Earth Venture – Suborbital mission that was designed to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere.  Four deployments (Aug. 2016, Feb. 2017, Oct. 2017, May 2018), to cover seasonal variation, were conducted using the NASA DC-8 aircraft. The measurements spanned the Pacific and Atlantic Oceans from the Arctic to the Antarctic, sampling the troposphere from the boundary layer up to 12 km. Over 300 species were measured from more than 20 instruments aboard the DC-8 (see http://espo.nasa.gov/atom/).

Steven Wofsy (ATom PI) and the ATom Science Leadership Team

^±Registration is open to ATom Science Team Members and members of the public, up to the size limit of the venue. If you are not currently a registerd participant, please send email to erin.czech[-at-]nasa.gov and request to be included.

In advance of their Science Workshop, the CCMI activity held a summer school on the campus of the Chinese University of Hong Kong focused on atmospheric chemistry as a component of the Earth System and the representation of processes in numerical models. You can read more here.

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

The CMIP6 landscape. Editorial in Nature: Climate Change.

Application of the compressible, nonhydrostatic, balanced omega equation in estimating diabatic forcing for parameterization of inertia–gravity waves: Case study of moist baroclinic waves using WRF. By M. Haghighatnasab et al. in the Journal of Atmospheric Sciences.

Stratospheric Influences on the MJO-Induced Rossby Wave Train: Effects on Intraseasonal Climate. By L.L. Hood et al. in the Journal of the Climate.

Convective hydration in the tropical tropopause layer during the StratoClim aircraft campaign: pathway of an observed hydration patch. By K.-O. Lee et al. in Atmospheric Chemistry and Physics.

Core Concept: To improve weather and climate models, researchers are chasing atmospheric gravity waves. By A. Mann in the Proceedings of the National Academy of Sciences of the Unted States of America (PNAS)

Discussion papers – open for comments:

A Comprehensive Assessment of Tropical Stratospheric Upwelling in Specified Dynamics CESM1.2.2 (WACCM). By N.A. Davis et al. in Geoscientific Model Development.

Bromine from short–lived source gases in the Northern Hemisphere UTLS. By T. Keber et al. in Atmospheric Chemistry and Physics.

Dehydration and low ozone in the tropopause layer over the Asian monsoon caused by tropical cyclones: Lagrangian transport calculations using ERA-Interim and ERA5 reanalysis data. By D. Li et al. in Atmospheric Chemistry and Physics.

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

Modulation of the MJO‐Related Teleconnections by the QBO. By P.-N. Feng and H. Lin in the Journal of Geophysical Research: Atmosphers.

ENSO modulation of the QBO: Results from MIROC models with and without non-orographic gravity wave parameterization. By Y. Kawatani et al. in the Journal of Atmospheric Sciences.

The Horizontal Spectrum of Vertical Velocities near the Tropopause from Global to Gravity-Wave Scales. By U. Schumann in the Journal of Atmospheric Sciences.

Discussion papers – open for comments

Inconsistencies between chemistry climate model and observed lower stratospheric trends since 1998. By W.T. Ball et al. in Atmospheric Chemisty and Physics.

An observation-based climatology of middle atmospheric meridional circulation. By T. von Clarmann et al. in Atmospheric Chemistry and Physics.

A reassessment of the discrepancies in the annual variation of δD-H2O in the tropical lower stratosphere between the MIPAS and ACE-FTS satellite data sets. By S. Lossow et al. in Atmospheric Measurement Techniques.

ESMValTool v2.0 – Technical overview. By M. Righi et al. in Geoscientific Model Development.

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

Advancing Research for Seamless Earth System Prediction. By P. Ruti et al. in the Bulletin of the American Meteorological Society.

Techniques and challenges in the assimilation of atmospheric water observations for numerical weather prediction towards convective scales. By R.N. Bannister, H. Chiplski, and O. Martinez-Alvarado in the Quarterly Journal of the Royal Meteorological Society.

An expanded definition of the odd oxygen family for tropospheric ozone budgets: Implications for ozone lifetime and stratospheric influence. By K.H. Bates and D.J. Jacob in the Geophysical Research Letters.

The effect of atmospheric nudging on the stratospheric residual circulation in chemistry–climate models. By A. Chrysanthou et al. in Atmospheric Chemistry and Physics.

Physical mechanisms controlling the offshore propagation of convection in the tropics. Part I: Flat island. By D. Coppin and G. Bellon in the Journal of Advances in Modeling Earth Systems.

Physical mechanisms controlling the offshore propagation of convection in the tropics. Part II: Influence of topography. By D. Coppin and G. Bellon in the Journal of Advances in Modeling Earth Systems.

Assimilation of satellite data in numerical weather prediction. Part I: the early years. By J.R. Eyre, S.J. English, and M. Forsythe in the Quarterly Journal of the Royal Meteorological Society.

Evaluating the Joint Influence of the Madden‐Julian Oscillation and the Stratospheric Polar Vortex on Weather Patterns in the Northern Hemisphere. By M.R. green and J.C. Furtado in the Journal of Geophysical Research: Atmospheres.

A stochastic representation of temperature fluctuations induced by mesoscale gravity waves. By B. Kärcher and A. Podglajen in the Journal of Geophysical Research: Atmospheres.

Changes in mean flow and atmospheric wave activity in the North Atlantic sector. By H. Paeth and F. Pollinger in the Quarterly Journal of the Royal Meteorological Society.

Monsoon Mission: A targeted activity to improve monsoon prediction across scales. By S.A. Rao et al. in the Bulletin of the American Meteorological Society.

Discussion papers – open for comment:

Response of middle atmospheric temperature to the solar 27-day cycle: an analysis of 13 years of MLS data. By P. Rong et al. in Atmospheric Chemistry and Physics.