HELCATS

This WP builds on the catalogue of identified CME by applying various analysis and modelling techniques in order to determine the kinematic properties (such as direction and speed) of the solar wind transients as they propagate away from the sun. This workpackage exploits the skills in geometrical modelling, inverse modelling and forward modelling from the groups involved, using the catalogues established in WP2. It includes a comparison of the performance of the techniques.

The work package consists of four tasks.

• Geometrical modelling of STEREO/HI CMEs
• Forward modelling of STEREO/HI CMEs
• Inverse modelling of STEREO/HI CMEs
• Comparison of modelling results

This activity takes detailed time elongation profiles and other characteristics determined from sequences of images taken with the STEREO/HI instruments for the CMEs identified in WP2. Using this information, and some underlying assumptions built into the different modelling techniques, it is possible to deconvolve plane of the sky propagation into the actual kinematic properties of the CME.

Task 1: Geometrical modelling of STEREO/HI CMEs

The objective of Task 1 is to perform geometrical modelling of the STEREO/HI CMEs, identified and catalogued in WP2, to derive their kinematic properties. This allows us to project back to the Sun and forward to specified solar system locations. From time-elongation maps (J-maps) generated from the HI data, the time-elongation profile of each CME will (where possible) be extracted and analysed using a range of single-spacecraft and stereoscopic geometric models (see Davies et al. 2012) to provide estimates of CME propagation speed, direction and potentially size; the STEREO/HI catalogue will be augmented with this information. Back-projected CME launch time/location, derived from the geometrical modelling, will be incorporated into the catalogue. This enables potential source signatures associated with CME onset to be identified (WP4.1). The geometrically-modelled CME speeds/trajectories will also be used to generate a catalogue of CME arrival time estimates at Mercury, Venus, Earth, Mars and Saturn, thereby providing support to European-funded space missions around these planets. The in-situ observations of CMEs will be compared to their white-light counterparts in WP4.2. The catalogues will be integrated in AMDA, offering access to the catalogues to the community of planetary scientists that use the European Research infrastructure (EUROPLANET).

Task 2: Forward modelling of STEREO/HI CMEs

The principal objective of Task 3.2 is to apply the GCS (Graduated Cylindrical Shell) model (e.g. Thernisien et al. 2006; Bosman et al. 2012) to the STEREO/HI observations of the CMEs in the WP2 catalogue. This will enable CME geometries, speeds, propagation directions and mass estimates to be derived. As in Task 3.1, the catalogue will be augmented with this information, as well as back-projected launch time/location and forward-projected arrival time estimates at various solar system locations. Note this task includes updating the STEREO/COR2 CME catalogue, initiated in the SOTERIA FP7 project, until the end of 2011 (this also includes forward modelling).

Task 3: Inverse modelling of STEREO/HI CMEs

Task 3 will prototype the use of inverse modelling to derive typical parameters (speed, size and mass) for the CMEs in the STEREO/HI CME catalogue (speed, size and mass), for photospheric and low coronal source regions typically associated with CMEs.

Task 4: Comparison of modelling results

In Task 4, we will inter-compare the results of the geometrical, forward and inverse modelling of STEREO/HI observations (Tasks 1, 2 and 3, respectively), as well as comparing with the COR2 model results.

Description of work package.

Description of work package.

Description of work package.