engleski

The drag-based model in a complex numerical environment

The drag-based model (DBM), due to its simplicity and speediness of the calculation, is often used for forecasting kinematics of coronal mass ejections (CMEs) in the interplanetary space, especially for prediction of the CME arrival times and impact speeds at arbitrary position in the heliosphere. The model basically relies on the observational fact that the CMEs which are faster than solar wind decelerate, whereas slower ones accelerate and the dominant force acting on CMEs is the “aerodynamic” drag force. Furthermore, the basic DBM assumes the drag domination in the interplanetary space beyond 20 solar radii from the Sun and that CMEs propagate in steady unperturbed interplanetary environment. Therefore, the previous rudimentary DBM version is extended to the general option where perturbed environment is plausible and where the constancy of CME properties are relieved. This generalization provides an application of the drag-based model in a real-time space-weather forecasting and integration into a more complex numerical models, such as ENLIL, EUHFORIA, etc. The basic and advanced on-line prognostic tool as well as the demonstration of the DBM integration into ENLIL-produced background solar-wind data are freely available on the 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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