ISWAT - International Space Weather Action Teams 

The kinetic forces induced by the (flare) reconnection processes make the CME propagate fastly away in all directions from the rotating Sun. For forecasting purposes, we need to know the initial speed, propagation direction and geometry of the CME as well as the uncertainties of the measurements. Furthermore, models need to be capable to simulate physical processes telling us at which distances the kinetic forces cease due to the drag by the ambient solar wind. Transit times and consequently geomagnetic effects are strongly depending on the impact speed of the CME. .

• The CME front itself is a subjective boundary and may in most cases picture the shock front, but sometimes also the magnetic structure. Those are two different CME signatures covering different physical processes in the solar wind interaction, hence, evolve differently.
• Another key problem is that CMEs are optically thin structures and line-of-sight integrated white light images, that are the standard imagery to track CMEs, may not be sufficient to get reliable kinematics and geometry. Even having non-standard stereoscopic data showed, that we are not able to fully resolve the complex CME structure in 3D. A problem of a higher degree is the CME’s magnetic field (most important its Bz component). It cannot be measured in interplanetary space from remote sensing data, and in-situ data show only local variations of the magnetic structure and may therefore be also insufficient to reconstruct the global magnetic orientation.
• The interaction process with the solar wind (see Cluster H1), in a simple way described as drag force, is not fully understood. The uncertainties, the lack of measurements, hence, the reliable input for physics-based models is another issue that we need to focus on in our studies.

A great community effort to improve CME propagation tools and solar wind forecasting/modeling: Get in the ring and face an open competition! Unite and combine available data, models and ideas.

• Analysis, modelling and prediction of interplanetary space (solar wind, CMEs) and their
  solar sources (active regions, flares, coronal holes - S2, H1, ...)
• Definition and quantification of uncertainties for the observational input parameters to
  CME propagation models 
• Development of CME propagation models for isolated and complex events
• Assessment and improvement of capabilities to predict CME arrival and impact at L1.
• Generating inputs to global space weather roadmap.