The fifth Chemistry-Climate Model Initiative (CCMI) Science Workshop will be held in Toulouse at Centre International de Conférences of Météo-France, 13-15 June 2017.

The Chemistry-Climate Model Initiative (CCMI) is a joint activity between Future Earth's International Global Atmospheric Chemistry (IGAC) Project and the World Climate Research Programme's (WCRP's) Stratosphere and troposphere Processes and their Role in Climate project (SPARC).

The scope of this international activity is to study the chemistry and dynamics of the global troposphere and stratosphere in a one-atmosphere approach in global models in order to understand the complex interactions and feedbacks between them and to understand their impact on climate, air pollution, and the ozone layer. Particular goals are to challenge the performance of these models by observations and process analyses, and to disentangle the different natural and anthropogenic drivers of observed changes.

CCMI consists of a wide range of researchers, including chemistry-climate modellers, observationalists, and data analysts, which are all encouraged to join our Science Workshop 2017.

The main focus of the workshop will be on the most recent analyses of CCMI phase-1 simulations, which are centered on understanding trends and interannual variability of tropospheric and stratospheric composition over the past and into the future, and how the composition interacts with changes in the physical climate. Specific topics of the workshop include:

• Identifying natural and anthropogenic drivers of past and future composition changes and their implications for climate, air quality, and the ozone layer;
• Evaluating model ability to simulate past and predict future composition changes;
• Augmenting the use of ground-based, balloon, aircraft and satellite observations for process-oriented model evaluation;
• Investigating novel ways to use observations and models to constrain Earth-system processes;
• Analyzing stratosphere-troposphere coupling, also its impact on the ocean;
• Understanding the causes of inter-model differences;
• Linking model performance to future projections.

	Scientific committee
		Michaela Hegglin	University of Reading	CCMI leader
		the IGAC/SPARC CCMI Scientific Steering Group

	Local organizing committee
		Béatrice Josse	Météo-France	CNRM
		Virginie Marécal	Météo-France	CNRM
		Martine Michou	Météo-France	CNRM
		Isabelle Varin	Météo-France	CIC secretary
		Jean Maziejewski	Météo-France	CIC secretary
		Philippe Caille	Météo-France	CIC