International Atmospheric Transport Modelling Workshop 2024

Vienna International Centre
Vienna, Austria 
(Note: In case of an unforeseen contingency the workshop can be held in an online format)

3-5 July 2024

The working language will be English


The objective of the workshop is to consolidate a forum for scientific knowledge exchange to strengthen the Atmospheric Transport Modelling (ATM) community affiliated to CTBTO’s verification regime. This forum is for specialists and  enthusiasts who seek a common goal in building this capacity.

The three main areas to cover are: 

  • In general: Technological advancements in Atmospheric Transport Modelling pertinent to the improvement of CTBT’s radionuclide verification technology. 
  • More specific: Uncertainty quantification and its scientific methods for data analysis to gain more confidence in ATM.
  • Datafusion: Methodologies to spatial-temporally link SHI (seismic, hydroacoustic, infrasound) and RN (radionuclide) events.


Theme I
An operational ATM system and what to expect from it.


  1. CTBTO’s ATM pipeline (CTBTO-FLEXPART and visualizing the ATM data with WebGrape).
  2. The strengths, weaknesses, and future of different ATMs (FLEXPART, HYSPLIT, others).   
  3. Wet/dry deposition, turbulence, and the dispersion of different radionuclides.
  4. Spatial-temporal (source-receptor) sensitivity in general.
  5. High-resolution ATM: Preparing for ECMWF’s future resolution improvements and accompanying challenges when it comes to downloading and locally processing (and storing) with full resolution.

Theme II
Addressing open scientific problems to enhance CTBTO's analyses


  1. Ensemble prediction systems and the feasibility of backward ensemble analysis. 
  2. Source-term localization and background estimation (e.g. statistical approaches and nudging).
  3. High-resolution ATM (e.g., WRF) for mesoscale simulations (e.g., for more confidence in localization analysis). 
  4. Uncertainty quantification (for the above).

As always, CTBT-related contributions on additional relevant topics are also welcome.

The workshop is aimed at all scientists, engineers and other persons involved in atmospheric transport modelling. 

Please be informed that the Provisional Technical Secretariat solicits presentations and posters from participants on the topics of the workshop. 


Applicants are requested to register online at the Commission’s CTNW platform by the registration deadline of 8 April 2024. 

Financial support may be available to a limited number of participants. Such assistance must be requested at the time of registration (by selecting the relevant box during online registration) and no later than Monday 8 April 2024. 

Financial support will be considered only for those who have submitted an abstract that will be accepted. Participants are strongly encouraged to first seek travel and participation funds from non-CTBTO sources.

States Signatories wishing to nominate experts are requested to inform the Provisional Technical Secretariat (see Point of Contact) through their respective Permanent Mission by the deadline set for application.

Applicants are invited to submit an abstract relevant to the objectives of the Workshop at before the registration deadline. 

Applicants will be prompted to select whether they prefer a poster or an oral presentation (see also: Other Pertinent Information).

Note: By submitting an abstract, the applicant confirms that the submitted abstract represents their own work or ideas, and that in all cases material from the work of others is acknowledged, and quotations and paraphrases are clearly indicated. It is also hereby declared that the submitted abstract adheres to scientific and professional ethics regarding plagiarism, fabrication, and falsification. Any violation of these requirements may result in the rejection of the submitted abstract.

Applicable to PTS-funded participants only

In accordance with the Staff regulations and rules and Administrative Directives, the PTS will provide the following:

  • A Daily Subsistence Allowance (DSA) that is sufficient to cover the related expenses during the workshop program will be paid on the first day of the workshops to the participants; 
  • The PTS travel agent will reserve, issue and forward the flight ticket to the participants for the most direct and economic route;
  • Funded participants are not allowed to purchase their own tickets unless, under exceptional circumstances, be authorized to do so and only if this proves to be most cost efficient for the PTS;
  • The PTS will book a hotel and cover the costs for the accommodation; and
  • Health insurance will be provided that covers the duration of the workshop. 

Requirement: Scanned passport copies.



  • PowerPoint presentations (shall not exceed 20 minutes).
  • Posters (should be in either A0 or B1 portrait format).
  • Round table discussion for two relevant workshop topics. Applicants can submit a separate abstract (on top of the presentation or poster) for a topic that they deem of particular importance to the workshop. The respective participants are then able to (co-)moderate the round table discussion, which will be arranged beforehand.    

Participants should apply for visas, if needed, upon receipt of an acceptance Note Verbale from the Secretariat, in order to ensure timely processing. 

Health/Accident Insurance 
It is strongly recommended that prior to departure all participants should acquire health and accident insurance for the duration of the workshop.

Point of Contact

Capacity Building and Training Section (IDC/CBT)
CTBTO Preparatory Commission
Vienna International Centre
P.O.Box 1200, 1400 Vienna, Austria 
Tel :    +43 1 26030 6132 
Email: [email protected]