engleski

The drag-based model application

The drag-based model (DBM) is an analytical model appropriate for calculating kinematics of coronal mass ejections (CMEs) in the interplanetary space and allows the prediction of their arrival times and impact speeds at any point in the heliosphere (“target”). The model is based on the assumption that beyond a distance of about 20 solar radii from the Sun, the dominant force acting on CMEs is the “aerodynamic” drag force. In the previously used form of DBM, the input parameters of the model are chosen on statistical basis, considering average and unperturbed conditions in the interplanetary space and common CME properties which are not necessarily appropriate for a particular CME under study. Therefore, we advanced the model, providing a DBM usage in a perturbed and time dependent environment without constraint on the distances above 20 solar radii. A modified and extended version of DBM is suitable for various applications, starting from automatic least-square fitting on initially detected CME kinematic data suitable for a real-time space-weather forecasting system, and ending with an embedding of the DBM into various numerical simulations of the interplanetary ambient conditions (solar wind speed, density, CME– CME interactions, etc.). For example, the DBM could be embedded into numerical codes of ENLIL, EUHFORIA, and similar advanced numerical models. A demonstration and evaluation of already available versions of the tool are discussed, and their feasibility of synergy with different numerical models is presented. Various DBM versions are available at web-site: http://www.geof.unizg.hr/~tzic/dbm.html. We acknowledge the support of European Social Fund under the “PoKRet” project.

methods: analytical ; methods: numerical ; solar–terrestrial relations ; solar wind ; Sun: corona ; Sun: coronal mass ejections (CMEs)

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