Workshop: Stratospheric predictability and impact on the troposphere

ECMWF | Reading | 18-21 November 2019

Figure courtesy: Corwin Wright

Workshop description

This workshop will bring together experts to discuss and propose ways forward in representing the stratosphere in current and future numerical weather prediction models (1-50 km resolution, forecast lead times from medium-range to seasonal), and pathways by which better treatment of the stratosphere can improve predictive skill in the troposphere. The topics will include understanding and diagnosing stratosphere-troposphere interactions, improved parametrizations and numerical schemes, the role of water vapour and ozone, observational evaluation and data assimilation. The aim of the workshop is to provide guidance to ECMWF on the priorities for representing the stratosphere in the coming decade.

The workshop will aim to shed light on the following key questions:

  • Which stratospheric processes are important for improved tropospheric predictability on medium-range to seasonal timescales?

  • What are the pathways and/or mechanisms for stratosphere-troposphere coupling? What can be done to represent these pathways and processes more accurately in NWP models?

  • Which tropospheric processes are important to represent accurately for improved stratospheric predictability? What is the role of teleconnections and how do we meaningfully evaluate their strength on medium-range to seasonal timescales.

  • What are the best tools and metrics to objectively evaluate the strength of the stratosphere-troposphere coupling, and, the skill provided by the stratosphere in tropospheric predictability?

  • What can be done to eradicate persistent stratospheric biases shared by many models? Is there an indication that certain biases are more important than others for tropospheric predictability?

  • Can physical parametrizations be improved in the stratosphere? Are the assumptions made in the parametrization design valid in high-resolution models, in which many processes (e.g., gravity waves) are partially resolved?  How do the resolved processes interact with the parametrized processes?

  • What are the important numerical issues to bear in mind when developing high-top NWP models?  

  • Can we use output from observational campaigns to improve the representation of the stratosphere?

Attendance

If you wish to attend this workshop, please complete the registration form before 31 July 2019.

Organising committee

Inna Polichtchouk, Peter Bechtold, Michail Diamantakis, Robin Hogan, Irina Sandu, Tim Stockdale, Nils Wedi