Forecasting CMEs - transit times and impact speed 

The drag based model (DBM) is an analytical tool which calculates the transit time and impact speed of coronal mass ejections (CMEs). The analytical drag based model covers the differences in speed as well as density between the CME and the ambient solar wind flow. In addition it takes into account the size of the CME. The method is described in detail in Vršnak and Žic (2007, A&A, 472, p.937), the evaluation of the tool is given in Vršnak et al. (2014, APJSS, 213, id.21), the further development of the tool is published in Žic, Vršnak, and Temmer, 2015 (ApJSS, 218, id.32). 

Recently, the ensemble version of DBM, DBEM, was developed and released as ESA SSA service. For more details see Dumbovic et al., 2018.


  • Real-time DBM+ESWF combines the results from the solar wind forecast and gives the current interplanetary conditions in which an 'almost real-time' CME might propagate
    (Note that this option is only meaningful for Earth-directed CMEs!).
  • Custom DBM uses the interplanetary conditions and individual targets as given by the user
  • Input DBEM has real-time and custom options and one may apply ESWF to estimate the ambient solar wind speed at target Earth. Input is given by the user for CME characteristics, its uncertainties, and target from which a probability of impact is given and for the impacting events a range of possible arrival times and impact speeds
  • Documentation for all services includes a manual and further references for interested users

Results from calculation:

  • CME arrival time and impact speed as well as travel time are given
  • v(R) and R(t) plots as well as an animation of the CME geometry as propagating in interplanetary space is shown
  • A zip file containing numerical and visual results can be downloaded

Please use the ESA services DBM and DBEM for calculating CME arrival times and impact speeds at different targets.

Example output:

Kinematic evolution Animation