SpreadFast Project

The CASHeW framework provides a streamlined framework of data analysis and data-driven modelling procedures for the quick characterization of coronal shocks and their particle acceleration potential. It uses automated techniques for the detection and fitting of the coronal front kinematics and the extraction of their physical parameters. The framework is described in detail in Kozarev et al. (2017)¹. It contains several tools for the characterization of EUV fronts observed with the Atmospheric Imaging Assembly (AIA) instrument on the Solar Dynamics Observatory (SDO), whose products are relevant for determining the level of SEP acceleration low in the corona. The coronal bright front kinematics (CK) module characterizes the kinematic evolution of EUV fronts (Fig. 1A). Its output is passed to the Coronal Shock Geometric Surface (CSGS) module, which generates 3D geometric models of the fronts for all epochs of the EUV observations (Fig. 1B). The density and temperature characterization (DTC) module uses the multi-wavelength AIA EUV data to calculate DEM models for the fronts, for every pixel and observational epoch in the AIA sub-frame. This is the basis of estimating the density, density change, and Alfvènic Mach numbers. Finally, the Magnetic Field orientation and Heliospheric Connectivity (MFHC) module creates global coronal magnetic field maps (up to ∼2.5 R_ʘ) just prior to the event (Fig. 1C). It combines these maps with CK and CSGS module output to produce shock-to-field angle and heliospheric SEP spread diagnostics.

As part of the proposed activity, in Work Package 2 we will develop for the CASHeW framework a synthetic synoptic shock module (S3M), which will produce synthetic shock waves from Active Regions (ARs) with the potential to erupt, on continual basis. This module will be developed taking into consideration previous observations from the CASHeW catalog, and studies performed by the team. It will be tested on actual solar eruptions, and will use pre-determined typical shock dynamics parameters (Work Package 3). It will interact with the data-driven coronal magnetic field and plasma models, to produce the necessary parameters for time-dependent modelling of the diffusive shock acceleration of ions. Note that for the purpose of the proposed work, we assume that most of the acceleration occurs at the shock waves, and not in flares. This assumption may be relaxed in future work if suitable models of source ion spectra are available.

Another addition to the prototype system (WP2) will be functionality to characterize the shock wave driver, the amount of overexpansion, if any, as well as its stand-off distance from the leading shock front. This information will be useful for the development of the typical eruption parameter tables in Work Package 3, as multiple scientific results point to the driver (eruptive filament or coronal loops) overexpansion actually causing the shock wave.

Finally, during the development of the prototype forecasting system, we will evaluate the possibility for future use of data from the current ESA Proba-2 mission (the SWEAP EUV imaging instrument), as well as from the future ESA Proba-2 mission (ASPIICS coronagraph instrument).