Related Activities

CFMIP is related to a number of other activities, which include other WCRP programmes, international observation campaign and model intercomparison projects.

WCRP Grand Challenge on Clouds, Circulation and Climate Sensitivity

In 2013, WCRP initiated Grand Challenges which target several science issues to be solved within ten years in climate research area. Read more about GCs ...

Among seven GC themes, Grand Challenge on Clouds, Circulation and Climate Sensitivity is particularly relevant to the CFMIP. In this "cloud GC", four important questions have been identified;

  • What role does convection play in cloud feedbacks?

  • What ontrols the position, strength and variability of storm tracks?

  • What controls the position, strength and variability of the tropical rain belts?

  • What role does convective aggregation play in climate?

For more details, please see the cloud GC position paper in Nature Geoscience:

Bony, S., B. Stevens, D. Frierson, C. Jakob, M. Kageyama, R. Pincus, T. Shepherd, S. Sherwood, P. Siebesma, A. Sobel, M. Watanabe, and M. Webb, 2015: Clouds, circulation and climate sensitivity. Nature Geoscience, 8, 261-268, doi:10.1038/ngeo2398.

The cloud GC has opened a number of new opportunities including workshops, summer schools model intercomparison, and observational campaign. An initial accomplishment of this GC activity has been summarized by Sandrine Bony and Bjorn Stevens.

CFMIP/GCSS Intercomparison of LES and SCMs (CGILS)

The EUCLIPSE project (2010-2014) was an international effort, funded under theme 9 "Environment" of Framework Program 7 of the European Union, designed to improve the evaluation, understanding and description of the role of clouds in the Earth's climate with a focus on the cloud feedback in a warming climate.

Cloud feedbacks in Earth System Models (ESMs) remain the largest source of uncertainty in projections of future climate. They are also a major contributor to uncertainty in other feedbacks (e.g., surface albedo, carbon cycle) in the Earth System. Through interactions with the large-scale circulation, cloud processes also contribute to synoptic circulations and regional climate. They are therefore critical to the prediction of future changes in precipitation patterns, climate variability and extreme events.

The central objective of EUCLIPSE is to reduce the uncertainty in the representation of cloud processes and feedbacks in the new generation of Earth System Models (ESMs), in support of the IPCC's fifth assessment report. Novel, process-oriented evaluations of clouds in present-day and future climate simulations made by the leading European ESMs will identify the cloud types and processes responsible for the spread in climate sensitivity and future precipitation changes across the models, and for deficiencies in the simulation of the present-day climate. The new diagnostics and metrics developed in EUCLIPSE will inform targeted sensitivity experiments to isolate the processes responsible for cloud feedback uncertainty.

In EUCLIPSE, four distinct communities will work together across a set of integrated work packages over a four-year period: the observational community will provide state-of-the-art measurements from ground- and space-based active and passive remote sensing; the numerical weather prediction community will provide analyses of short timescale model biases induced by cloud processes; the cloud modeling community will provide fine-scale models as an additional tool for understanding cloud behavior in a changing climate; finally, the climate modeling community will synthesize the physical understanding and observational constraints identified by the other communities to improve the representation and assessment of cloud processes in ESMs and so improve the predictive skill of ESMs.

The strength of the EUCLIPSE project is the combination of detailed modeling and observation at the level of individual clouds and the evaluation and analysis of clouds in the climate system in global climate models using the latest diagnostic techniques and satellite products.

The EUREC4A project, the Field Study, is a French-German initiative in support of the World Climate Research Programme's Grand Science Challenge on Clouds, Circulation and Climate Sensitivity. EUREC4A will take place between 20 January and 20 February 2020 with operations based out of Barbados.

EUREC4A aims at advancing understanding of the interplay between clouds, convection and circulation and their role in climate change: How resilient or sensitive is the shallow cumulus cloud amount to variations in the strength of convective mixing, surface turbulence and large-scale circulations? How do the radiative effects of water vapor and clouds influence shallow circulations and convection? What are the implications for the spatial organization of clouds and convection in the tropics, and for climate sensitivity?

To address these questions the core, and presently supported, EUREC4A measurements will focus on quantifying how cloud amount in shallow cumulus layers responds to changes in the large-scale environment, and how shallow clouds affect the radiation field and contribute to convective aggregation. The measurements will also test retrievals of cloud and atmospheric properties, and numerical simulations of shallow cumulus cloud regimes by large-eddy simulation, weather prediction and climate models. Through international cooperation complementary objectives could be explored. These range from investigations of the role of ocean mesoscale eddies in air-sea interactions and the organization of shallow clouds, to the much broader question of the dynamics of the Atlantic Tropical Convergence Zone.

The nucleus for the EUREC4A Field Study involves the deployment of two research aircraft (the German HALO and the French ATR42), an array of research vessels, advanced ground based remote sensing, a new generation of sophisticated satellite remote sensing and state-of-the-art turbulence-resolving modelling (100 m, over thousands of km). These operations build on a decade of measurements in the tropical Atlantic, initiated with the establishment of the Barbados Cloud Observatory in 2010, and continued with two aircraft campaigns with HALO: NARVAL in December 2013, and NARVAL2 in August 2016 (information about these experiments is provided here).

EUREC4A operations will focus on an area over the shelf oceans east of Barbados (57 W 13 N) for a six week period between 12 Jan and 23 Feb 2020, with aircraft operations between 20 Jan to 20 Feb 2020. This period will overlap with ADM-Aeolus and EarthCARE, two flagship satellite platforms of the European Space Agencies Living Planet Programme. More information about EUREC4A is provided in an overview paper describing the field study.