Magnetic cloud Bs events and their dependence on cloud parameters

It had been found that the duration and intensity of the southward interplanetary magnetic field within magnetic clouds (the magnetic cloud Bs event) correlate linearly with the ecliptic latitude of the cloud's central axial field, the one of eight characteristic parameters of expanding magnetic clouds. On the basis of the parameter list determined using the expanding magnetic cloud model for all clouds to be examined, this work examines the dependence of magnetic cloud Bs events on the other seven parameters as well as the ecliptic latitude of the cloud's central axial field. The correlation of the duration and intensity of magnetic cloud Bs events with the ecliptic latitude of the central axial field hats been confirmed by the new parameter list with correlation coefficients higher than our earlier study. It is found among the eight parameters that in addition to the ecliptic latitude, the strength of the central axial field, the cloud's bulk speed, and the relative impact distance of the spacecraft to the cloud's central axis are the other parameters that are closely associated with the duration and intensity of magnetic cloud Bs events. There are most probable values for most of the eight parameters of expanding magnetic clouds. In predicting the duration and intensity of magnetic cloud Bs events using the expanding cloud model these most probable values may be used to replace those model parameters that are unavailable from solar observations. This provides a possibility to predict the duration and intensity of magnetic cloud Bs events based on a few parameters that are available from solar observations.