Stream-interacting magnetic clouds causing very intense geomagnetic storms Original Research Article

In this work we calculate the magnetic field parameters for two stream-interacting magnetic clouds using Burlagaʹs model and compare with their observed magnetic field behavior. Presumably the model does not take into account the effects of interaction between the magnetic cloud and the high speed stream, so we could estimate quantitatively the increase in the peak Dst value due to this interaction. For this purpose, the observed Dst was used together with the Dst values calculated with the modified Burton formula, using as input the observed parameters and the parameters obtained by Burlagaʹs model. Our results show that the peak Dst value can be increased from (at least) 60 to 100 nT due to the interaction between the magnetic cloud and the high speed stream overtaking it.